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CRF230F Forks - Replacement and Modification |
Click pictures to supersize.
Alphabetical table of contents
CRF230F riders discover how deficient the stock forks are when they try to ride quickly and/or on difficult terrain. Two methods for rectifying this deficiency are replacement and modification of the suspension. This web page addresses replacement and modification of the stock forks. I have personally performed most of the work mentioned. I have included information from many riders on ADVrider and ThumperTalk threads, with their permission. If you see any errors or omissions, please contact me. I also welcome unsolicited input. My email address is on my home page.
Fork Replacement - Replacing stock forks with CRF150R forks
A popular fork conversion is to replace the stock forks with USD (up side down) forks found on CRF150R, CRF150RB, CR85R, CR85RB, CR80R, and CR80RB models. The R models mentioned have smaller front/rear wheels than the RB models (R-17/14 vs RB-19/16). The forks are nearly identical, differing in spring rates, base valves, and damper rods. As discussed below, you will probably be replacing the springs, so either R or RB forks can be used. I will use the 'R' suffix and drop the 'RB' when mentioning the fork designation herein.
Note - there are other fork conversions you can do, such as these on ThumperTalk:
ULTIMATE FRONT END CONVERSION FOR CRF230F started by MetricMuscle with contributions by many others.
230 Fork swap Spring 2016 - options started by usedtobefast with many contributors.
I've come across at least a dozen of these projects, so don't get hung up on my 150R conversion being your only choice.
RedMesa has posted on ThumperTalk about his outline of five price / performance zones of fork modifications:
230 Fork swap Spring 2016 - options post #59
Link to RedMesa's web page with discussion of the five zone fork mods - Fork upgrade options
Lastly, here are two very good fork conversion projects by frickinjim:
CR80R/CR85R/CRF150R Inverted Fork Swap
CR/CRF125/250/450 Inverted Fork Swap
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The information is presented in the order I did the work. You can do the work in whatever order you want, but sooner or later, you'll have to visit each area described. Click on the topic to go to the discussion.
Forks, Fork springs, Fork suspension fluid, Fork protectors. Other information provided:
Front tire and frame clearance. |
Forks
The CRF150R, CR80R, and the CR85R forks will all work, although you will need 1 less part when using the CRF150R forks. Also note that the CRF150R forks use a 15mm axle, and the CR80R/CR85R forks use a 12mm axle. The CRF150R forks are designed for a heavier bike and thus have slightly better internals to handle the extra weight and will be better suited to the CRF230F. The larger OD of the axle means there will be less flexing of the CRF150R forks compared to the CR80R/CR85R forks.
I think it's a good idea to locate and buy forks as the first step. This can take considerable time, depending on where you plan to buy.
You can buy brand new forks from most Honda dealers, but you can often find much cheaper forks on eBay. Some eBay sellers offer forks in very good condition in the $300 - $500 range. Try to find a set that includes the triple clamps and axle to economize on shipping. Sometimes you can find forks on the web in motorcycle forums that have flea-market or for-sale categories.
If you buy used forks, disassemble them completely and check for any broken parts, worn bushings, scratched, nicked, or gouged fork tubes, and external damage to the fork outers. Replace or repair as needed. You may need to replace the fork seals but won't really know until you've ridden your bike with the forks mounted.
When working on your new forks, make sure to use torque values for the CRF150R forks and not the CRF230F forks. Front axle nut torque is an example. I suggest you buy the Honda CRF150R Service Manual from Helm, Inc. Besides torque values, it shows you the fork service procedure including disassembling everything and how to check for needed replacements due to wear. I used it when I replaced the springs and changed the fork fluid.
Helm is showing the 2007-2017 CRF150R/RB Service Manual as out of stock with no projected release date. The Service Manual sells for $34.95 plus shipping. eBay shows new and used paper copies in the $40-$60 range and a pdf version for $10.
CRF150R USD forks: 2007-2009, 2012-2017
CR85R USD forks: 2003-2007
CR80R USD forks: 1996-2002
Fork springs
Unless you're a light-weight rider or your riding style is very tame, you'll probably want to upgrade the fork springs to a higher/stiffer rate. The CRF150R and CR80/85R bikes are designed for smaller riders and sprung accordingly. When used on the heavier CRF230F with an adult on board, the stock springs will be much too soft.
I weigh 200 lbs. and ride my 230F very lightly (no jumping or air time) on tight technical trails and .40 springs suit me just fine.
The first two sets are Factory Connection springs; the upper springs (rear) are stock CRF150R springs.
.42 and up are available from Cannon Racecraft. You have to sand down the spring guides a bit so the springs don't drag.
To install the springs, follow the procedure in the Honda CRF150R Service Manual or have a look at how I installed them below.
Markings on a set of Factory Connection .40 springs:
304654 (work order) .40 (spring rate)
Dry weights of bikes mentioned:
CR80RB 144
CR85RB 145
CRF150R 177
CRF230F 235
Nomenclature
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My use Fork cap Adjuster rod Damper rod |
Service Manual Fork bolt Adjuster rod Damper rod |
Parts Catalog Fork bolt Rebound needle Piston rod |
Before I start the actual description, I want to tell you something. When you buy used forks, you may find that there is some excessive wear and/or actual damage to one or more fork components. Over the last 10 years, I have bought used CR80/85R and CRF150R forks on eBay with great success. There have been several forks that I found were damaged. The most common damaged component has been the adjuster rod that connects to the fork cap, and that is used to adjust rebound damping.
Fork cap with adjuster rod in excellent condition. The rebound adjuster screw that sticks out of the top of the fork cap is actually the top end of the adjuster rod. When you screw this adjuster in and out, it lowers and raises the bottom end of the rod into and out of the rebound valving stack in the bottom of the fork. Whenever you need to remove the fork cap, you are instructed to unscrew the adjuster screw all the way out, until it lightly tops out. This will withdraw the lower end of the adjuster rod from the valving stack in the bottom of the forks. This is done to ensure that the tip of the rod is not damaged as you remove and replace the fork cap assembly.
After the fork cap is removed from the fork, you can unscrew the adjuster rod out from the bottom of the fork cap and check the internal o-ring.
The picture shows the fork cap and the top end of the adjuster rod with the o-ring. The part to the left of the o-ring is what sticks up out of the fork cap.
Remember the damaged forks I mentioned earlier? This is one such damage. Someone unscrewed the adjuster screw all the way to the top, and then proceeded to continue twisting it until the end busted free, right where the o-ring groove was. Perhaps the person thought the screw was going to come all the way out, just like the small air bleed screw right next to it. Guess what. The person deftly screwed the broken off piece back into the fork cap, and sold the forks to me as 'slightly used'. The 'Rebound needle' as Honda calls it, costs about $18, so it was easy enough to repair the damage and use the fork.
This short narrative is by way of preparing you for the first step in swapping springs - removing the fork cap (and connected adjuster rod). Use care.
Now here's the description of how I swap fork springs.
I've found the best way to mount the forks for working on them is to install them on the motorcycle, right in the triple clamps.
Mount the triple clamp with the triple clamp nuts set finger tight so the upper and lower clamps will move easily and allow the fork tubes to be inserted. Loosen all 6 fork pinch bolts. Slide each fork tube up through the triple clamp holes.
As you insert each fork tube, do step 1 to insure that the tubes don't drop out while you're working.
1 Tighten the lower triple clamp bolts to about 10 ft-lb.
Let the fork tubes hang freely; do not install the axle or brake caliper. The black rubber bungie shown is used to stabilize the forks so they don't tip from side to side while I'm working on them.
2 Unscrew the adjuster rod until it lightly tops out in the full out position. Carefully, as described above.
3 Unscrew the fork cap using a 17mm box end wrench. It may be over-tightened and take some effort. A six-sided wrench or socket will help prevent damage to the aluminum fork cap. In this picture, I'm using a 12-sided wrench because the fork cap was properly tightened and came loose easily. Unscrew until about 5mm of thread is showing. You'll feel a click as the fork cap threads disengage from the fork tube. If you keep twisting, you'll feel the click once per revolution. To check if the threads are really disengaged, use one hand on the fork cap and reach down to the axle mount with your other hand and lift both ends very slightly. You'll see the fork cap clear the fork tube and get a peek at the internal mechanism, as shown in the next picture.
This picture shows the steps for removing one fork cap, the other is identical.
Slide a 14mm open end wrench onto the lock nut hiding inside the spring. You have to force the coils apart slightly to get it all the way on the nut. You need to break the nut loose from the fork cap, so turn the top wrench counterclockwise and the lower wrench clockwise (looking down on the fork cap). Pay attention to the force required; not too little, not too much. You'll be tightening the lock nut up during reassembly.
Once the nut is free, you can unscrew the fork cap by hand.
Be careful. When the fork cap comes free of the threaded damper rod, it will be weakly supported by the adjuster rod. Slide the fork cap with adjuster rod up out of the damper rod.
All the while that the fork cap is free of the damper rod, the damper rod is free to drop down into the fork body. If you work at a normal pace, you'll probably get the fork cap with adjuster rod free and watch as the damper rod drops into the fork body. If you're working slower, the damper rod will drop away while you are lifting the fork cap free. Not to worry.
The fork cap with adjuster rod has been removed. Now remove the spring and set it in a container to allow fluid to drain off. I use a plastic bucket.
The damper rod has reached the bottom of the fork
Now do this all over again with the other fork cap.
After both fork caps and springs have been removed, then remove the forks from the triple clamps and place them upside down in a container for them to drain. Be careful turning the forks upside down - fork fluid will pour out and the damper rod and spring support will come sliding out (but not off because they are retained at the other end). It helps to get most of the fluid out if you pump the fork lower (smooth part) while holding a fork tube upside down. Again, be careful of fluid gushing out...
After you're satisfied that the forks and springs have drained sufficiently, continue. I like to let them drain for 30 minutes or so. Wipe the springs off and set them aside. Wipe the fork tubes off, collapse them fully, and stand them vertically with some support so that you can pour fork oil or suspension fluid inside.
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About fork oil. There are as many theories about fork oil as there are about engine oil. Everyone has their own preference (or not) and everyone will be glad to tell you why what they use is best (or not). You will have to decide on a brand, weight/viscosity, and fluid level. After years of using fork oil, I switched to using suspension fluid about 15 years ago. I did this because most fork tuning write-ups mention using suspension fluid and not fork oil. Supposedly, suspension fluid is higher quality and you have more viscosity range to choose from. Honda recommends Pro Honda HP Fork Oil and Pro Honda Suspension Fluid SS-8 in 5W and 10W depending on year and model of bikes. These are as good a choice as any, and I have used them with satisfaction over the years. I now use Amsoil Shock Therapy Suspension Fluid in #5 and #10. For these forks, I started with #5 but now use #10. You will have to select a brand and weight and try it. If performance is not what you want, adjust as necessary. |
Start with one collapsed fork. Measure 342 cc (11.6 oz) of fluid into a graduated container. Carefully pour the fluid into one fork tube. Also fill the damper rod with fluid as you pour. After all the fluid has been poured in, stroke the damper rod 5-6 times to remove trapped air. Also stroke the outer fork tube slowly, up and down. When you don't hear a gurgle, it's done. The Honda CRF150R/RB Service Manual shows a procedure where you extend the fork, cover the top of the outer tube with your hand and compress the fork leg slowly. Then remove your hand and extend the fork slowly. This is repeated 2-3 times.
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Regardless of which procedure you use, you want to get all the trapped air out so that you can accurately measure the fluid height. This is the only reason you are removing trapped air at this time. Later, as you handle the sealed forks, and you ride your bike, and possibly fall, air may become trapped inside the cartridge and fork valves. This is not a problem because the air will be expelled from the inner chamber as you continue to ride the bike normally. To reiterate - the only reason you want the air out now is to set fluid height. When fluid is removed during subsequent servicing, and the fluid volume is different between the two forks, this will indicate that all the trapped air was not removed during the previous service. You want fluid level/fluid volume the same so the forks are in balance. Having said all that, I note that in the last few years we are seeing forks with a spring in one fork only and different fluid levels, forks with no springs at all, and forks with compression on one side and rebound on the other and commensurate differing fluid levels. Well, for standard cartridge forks of the CRF150R vintage, I will go with the fluid level that Honda recommends at the same level in each fork, as accurately as I can measure. |
Once you are satisfied that all trapped air is removed, measure the fluid height in the fork. With the fork held vertical and totally collapsed, insert a ruler into the fork. In these pictures, I inserted a 150mm steel ruler all the way in to the end of the ruler. The fluid reads somewhere between 142 and 143 (easier to see live). The book calls for 141 mm, so I added a tiny bit.
I usually use a syringe that was sold for removing fork fluid. Recently, I bought some animal syringes at a farm supply store, and tried one (as shown here). It works better than the old one bought at a motorcycle shop.
Disposable Syringe 60 ml Luer Slip without needle 01-7360 - about $8. Similar on Amazon
Disposable Syringe 60 ml Luer Slip without needle 01-7360, Allison Medical - about $2. Murdoch's Ranch and Home Supply online
Du-Bro 800 1/8" x 3' I.D. Tygon Tubing - about $6. Amazon
60ml Fork Oil Tool Ruler Hose Kit Gauge Suspension Tuning Syringe Shock Adjuster - $3.36 Free shipping from Hong Kong!!! eBay
I ordered one on 17/01/03. The kit arrived on 17/01/24 - 3 weeks to the day. The syringe is almost identical to the one I bought at Murdoch's. Two included hoses are clear plastic that will probably get stiff with age but work fine now. I'm spoiled by the Tygon - never had one get stiff. The kit included a metal 6" / 150mm ruler. Other than waiting 3 weeks, the kit is entirely satisfactory.
I went back to Murdoch's and bought a smaller easier-to-handle 35 ml syringe for $1.19; didn't have to wait 3 weeks...
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Fluid height is one of those variables you can adjust to your preference. The higher the fluid level, and thus the smaller the air chamber, the harder the forks will resist bottoming. They will tend to stroke with more resistance, especially deep into their compression. If the forks never bottom and seem harsh, remove fluid in 5 cc decrements until they bottom now and then and stroke easier/softer. Conversely, the lower the fluid level, and thus the larger the air chamber, the easier/lesser the forks will resist bottoming. They will tend to stroke with less resistance, especially deep into their compression. If the forks bottom often, add more fluid in 5 cc increments until they don't bottom very often. |
Pull the damper rod up out of the collapsed fork. Snug the lock nut against the fork spring guide; not too tightly, you don't want to damage the plastic guide. Let the damper rod sink back into the fork.
The next step is to install the spring. After the spring is installed, you have to raise the damper rod up through the spring so you can screw the fork cap onto the damper rod. The Service Manual mentions a mechanic's wire attached to the lock nut on the damper rod before you start, then slide the spring over the wire and damper rod, and pull the damper rod up through the spring.
I don't care for this method. First off, I don't have an official "mechanic's wire" and I can't figure out how you would attach it to the lock nut, and secondly, I don't want a wire scraping the spring and other fork internals. I did consider using a cord or some heavy string, but getting it off when it's inside the spring end would be tedious. So a few years ago, I figured out a way that works for me. I sometimes use a small screwdriver and sometimes a fine needle nose pliers to manipulate the damper rod. Once I used a hooked tool.
Walk the damper rod: You have to reach through the spring and latch onto or against the damper rod and raise the rod and spring at the same time. You pull the tool out, and lower the spring by hand. You then re-insert the tool and engage the damper rod and lift both the rod and spring again. You keep doing this until the top of the damper rod can be grabbed while reaching in through the top of the spring.
Read how I do it and decide what you want to try. Have the screwdriver, pliers, or hooked tool nearby. You might want to read the Honda CRF150R/RB Service Manual to see how they do this part...
When you manipulate the damper rod, spring, and fork cap with adjuster rod, you have the potential to splash oil out of the fork. To prevent this, slide the various parts smoothly and not too fast during assembly. Note in particular that the damper rod will have oil inside it, and when you insert the adjuster rod inside it, oil will come out the top of the damper rod, so go slowly.
Wipe a spring clean and set it close by. Pull up the damper rod, release it, and watch it fall. You have to get the spring in before it falls too far. Actually you need to catch it before it falls into the fork. The damper rod will start to drop. Put the spring in, and don't splash the fluid around. Use your chosen tool to stop the damper rod from dropping. Walk the damper rod up the spring, as described above.
Reach in and pull the damper rod up through the spring far enough to screw the fork cap on a few turns. I grab the threaded end of the damper rod with one hand and push down on the spring with the other hand. In the picture, my finger on the back side of the spring is pushing the spring into the plastic guide, preventing the damper rod from dropping.
Carefully install the fork cap and adjuster rod. By hand, screw the fork cap onto the damper rod until it stops. Slide a 14mm open end wrench onto the nut. Holding it steady, use a 17mm box end wrench on the fork cap, and screw the fork cap down until tight. Remember back when I told you to take note of how hard these two were to separate? Try to match that tightening torque. Tight, but not too tight.
Screw the fork cap into the fork tube with the 17mm wrench. You want the fork cap snug, but not over-tight. The upper fork pinch bolt on the triple clamp will keep the fork cap from coming loose once the fork is mounted. The o-ring on the fork cap will keep the fork fluid inside. All that is necessary is for the cap to be tight enough to not come loose. You'll be glad it's not over-tight when you remove the fork cap for fluid replacement.
Set the fork aside.
Now do the other fork.
Ready to be mounted in the triple clamp.
Extra credit assignment; for those seeking more info CRF230F Fork Details
Fork suspension fluid
Correct fork fluid choice is critical to get good performance, suited to your riding style and terrain. I use Amsoil Shock Therapy Suspension Fluid #10 at the standard 150R fork oil height. Follow the procedure in the Honda CRF150R Service Manual or see my notes above.
Fork protectors, left and right; Fork protector bolts x6
Although you find riders who leave the fork boots off of conventional forks, it's not a good idea for USD forks.
The inner two protectors are new and fit the CR80R/RB, CR85R/RB and CRF150R/RB. The outer two protectors are used. Note the protectors get yellow with age and exposure to sunlight.
Caliper bracket kit
If you want to use your stock CRF230F front wheel and front brake with the CRF150R forks, you will need to install a brake caliper bracket that is designed for the purpose. I know of three caliper brackets: Applied Racing, Emig Racing, and Reger Engineering.
I have not bought nor used this Applied Racing Carrier, so I have no info to offer. Several riders have posted on ThumperTalk about using it; do a search.
CRF150R DUAL PISTON BRAKE CARRIER STK $79.99
EddieG offered this information:
The Applied Racing Carrier should work for a CRF150R size front wheel. Specifically it allows a larger dual piston caliper (CR or CRF 45150-MEN-006) to be used on the CRF150R wheel. I am trying to mount a CRF230F wheel to the CRF150R forks and the carrier does not provide any clearance benefits vs the stock carrier (no offset or distance from forks gained).
So not much use for this project.
I have not bought nor used this Emig Racing Caliper Bracket, which is a 2-piece bracket, so I have no info to offer.
CRF230F / CR85 FORK CONVERSION axle kit $275
Reger Engineering is no longer in business, so the availability of his caliper bracket is limited. A machinist friend of mine made a functional copy (shown in picture left) and they are for sale HERE. Follow the installation instructions provided with the kit.
You must use the correct axle and axle collars when using the CRF230F front wheel; see Reger front axle collars below.
Two brackets and two sets of axle collars are shown for clarity.
Heli-coil
You must tap and install heli-coils in the fork tabs where the brake caliper bracket is mounted. As it turns out, there are other thread replacement products also: Fix-A-Thred, Time-Sert, and Keen-Sert to name a few. The key is to get a long enough thread to allow for a good, solid seat for the caliper bolts. And then to use good quality bolts that won't stretch (like one set of bolts did for me) and tighten to the correct torque. I used Honda bolts:
90124-KZ4-J40 Flange bolt 8X35, $1.30ea x2 and 90107-KZ4-J40 Flange bolt 8X45, $1.20ea x2.
These are included in the caliper bracket kit.
I installed the Fix-A-Thred type of heli-coil on my second set of forks. I'd never worked with heli-coils on such a long length. Tapping was a tedious process and fraught with anxiety - nervous about getting it perpendicular. They weren't long enough to fill the entire length, and I had to install one on each end of each hole.
Nuts and bolts instead
bajatrailrider posted on ThumperTalk that he used nuts and bolts instead of heli-coils. What a great idea. So I did a little checking and decided that M8-1.25x48 or M8-1.25x50 bolts with locking nuts would work. I bought some nuts and bolts and after fitting them with the bolt heads outside and the nuts inside, I discovered that the nuts interfered with the rotor bolts and the bolts were a few threads too long, which also caused a problem. Smaller nuts didn't hold well and trimming the bolt threads was too labor intensive. Also, installing with the bolt heads inside did not work - too big.
After trying several other combinations, I arrived at the following - button head socket cap screws with small round heads. The small heads are mounted inside and clear the rotor bolts just fine. The flanged lock nuts are mounted outside (shown here) with a few threads showing. I was unable to find these bolts in 48mm length. If the look is not acceptable, you can use a band saw to shorten the 50mm bolts about 2 threads.
Bolt heads and inside view, showing clearance.
Click to supersize.
The bolts/nuts are cheaper and easier to install than heli-coils. Test rides did not reveal any problems. The caliper alignment did not vary and the nuts stayed tight. Bolt head clearance is not a problem; they are very much out-of-the-way. I will make up a caliper bracket kit that includes the new bolts/nuts in place of the original bolts.
The Hillman Group 44493 M8-1.25 x 50 Metric Stainless Steel Button Socket Cap Screw, 8-Pack - about $14 for pack of 8. Amazon
Fastenal and MSC also have comparable bolts. Buy a grade sufficient for 22 foot pounds tightening torque.
90309-428-731 NUT, FLANGE (M8-1.25) about $2.08 ea. DiscountHondaParts.com
Front axle, axle nut, and washer
CR85R, CRF230F, and CRF150R axles and axle nuts.
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Left
Honda CR85R axle, washer, and nut.
Reger "Wheel Spacers and Center Support" kit. |
Center
Honda CRF230F axle.
CRF230F axle distance collar and wheel collars.
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Right
Honda CRF150R axle, washer, and nut.
Stock CRF150R axle collars.
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Note the nut/axle sets; no two are alike.
Reger front axle collars
Reger Engineering sells front axle collars for use when installing the CRF150R front axle and forks with a CRF230F front wheel. If you are unable to contact Reger to purchase these, you can make your own collars (or have a machine shop make them up). I measured a used set of collars...
Note - the axle collars are included in the caliper bracket kit.
All measurements are in MM.
Something doesn't look right.
How can a 14.94 i.d. collar fit a 14.95 axle?
I used a caliper to measure the i.d. because I don't have an inside mike small enough.
I'm not that good doing inside measurements with a caliper.
So I suggest using 14.955 as the i.d. of the collars.
Both collars are stainless steel; the smaller one was very slightly magnetic on one end.
Yes, the collars have different o.d.; one fits inside a seal and the other inside a plastic water shield.
There is scoring on the surfaces of both collars: I ride lottsa miles and even metal will give way to plastic and rubber if there is an abrasive and plenty of time.
Triple clamps
You can use CRF150R, CR80R, and CR85R triple clamps to mount the CRF150R forks.
You must modify the triple clamps as described in the next topic below 'Lower triple clamp modification'. Once this is done, the triples install on the steering stem and the CRF150R forks slide right in.
Unlike the stock CRF230F triple clamps, there is no place to mount the CRF230F key switch on this triple clamp. You can make a mount for the key switch and attach it to the triple clamps, the handlebars, or the frame near the steering stem. Or somewhere else that works for you.
You can remove the key switch altogether. You will loose some measure of security, so be sure you want to take the risk before proceeding.
Here is a description of how to rewire your bike if you remove the key switch.
Do this when you've got the fuel tank off to relocate the CDI.
Trace the wire bundle from the key switch to it's junction with 4 wires under the fuel tank.
Disconnect all 4 wires: Black/white, Green, Black, Red.
Pull the key switch wire bundle away; it will go away when you remove the stock triple clamps with key switch attached.
Plug the Black wire male connector into the Red wire female connector.
Cover the ends of the Black/white wire connector and the Green wire connector with electrical tape.
Done.
The small tab sticking out from the lower right of the lower clamp (facing it) is used to mount a brake hose guide on the stock CRF150R. The guide is positioned well when a number plate is mounted on the triple clamp. I mounted a headlight and the guide was no longer useable. So I mounted a brake hose guide I found in my box-o-parts; you can just make it out here.
Lower triple clamp modification
In short, press out stem, machine .25", press in stem.
The CRF150R's steel steering stem is 1/4" too short to fit the CRF230F frame. You can modify the 150R triple clamps to fit the 230F:
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Remove the steering stem nut and washer, then slide the upper triple clamp off. Remove the lower nut and the 4 fork pinch bolts. Scribe the steering stem just above the bearing. Call this the 'bearing line'.
Scribe a line about .25" away from the 'bearing line' marked earlier, closer to the just-machined end. Chuck the steering stem in a lathe and turn the shaft down to the I.D. of the lower steering bearing in the area between the two scribed lines. This allows the bearing to slide down to the lower clamp. The area just above this was under the bearing, so it will already be the correct diameter for a press fit of the bearing. Press the steering stem up through the lower clamp. If you measured and machined the inner step accurately, the second scribed line will be at the top edge of the lower clamp. Slide the bearing onto the steering stem, gently coaxing it down to the lower clamp. Finish reassembly of the triple clamp parts.
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Alternatively, you can press out the 150R stem and press in a '90 - '95 XR250R stem. No grinding or lathe work necessary. Landerz-TT.
I discovered that '87 - '95 have the same steering stem part number: 53200-KT1-770. I found 7 on eBay; cheapest was $20; $32 with shipping. I bought it.
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Here's the important part - the stem lengths compared.
The XR is longer! But how much longer?
Although it looks like 5/16" (top of ruler), it's actually a smidgen over 1/4". (Parallax skews the view.)
Exactly what we need.
All I have to do is press the stems out of the XR and 150R lowers, then press the XR stem into the 150R lower clamp. Lots easier than all that grinding and machining.
But wait, there's more.
There are 7 parts on the CRF150R triple clamps; there are 8 parts on the XR triple clamps. In the list below, you need 2 bearings, so count bearings as 2 parts. All four bearings (upper/lower, 150R/XR) are identical and they are the same as the CRF230F upper and lower bearings. The upper dust seals are the same; lowers are different. The nuts are finer pitch on the 150R; coarser on the XR. The washers are different.
Bottom line - if you use the XR stem, use the XR hardware. But bearings are same-same-same.
The last two parts in each list sit on top of the upper clamp, and are shown on the Handlebar parts page.
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A note about the steering stem bearings AKA head pipe bearing I've never had to replace the steering stem bearings on my two CRF30F bikes. Even when I replaced the stock forks with USD forks, I re-used the stock bearings. As I later found out, the CR80/85 and CRF150R bikes use the same steering stem bearings as the CRF230F. While creating this page and performing the steering stem modifications, I decided to buy new steering stem bearings to insure that I wasn't re-using anyone's cast-offs or poorly maintained bearings. When I ordered the new bearings, I noticed that there was a part supersede 91015-425-832 replacing 91015-425-831. No biggie, happens all the time. I looked at the 2003 on-line parts fiche and it showed the supersede also, so I have no idea when the new part came on-line.
The new bearing is 2.7mm taller and the rollers are longer, providing more bearing contact area. There are 19 rollers in the old bearing and 20 in the new bearing. The races appear identical.
Bearings in their races for a comparison. When installed in the head pipe, the new bearings extend about 1mm more than the old setup, with both races (2 shown on the right). After studying these parts for a while, I believe that Honda has covered the bases - even though the new bearings are taller, they still work just fine because of the location where the bearings are used. There is empty space inside the head pipe, and the extra height of the bearings just pokes into that empty space. I suppose a different use where the vertical clearance was very tight would pose a problem. But for this application, NOT TO WORRY. And you don't have to swap races if the old ones are in good shape. I read that these steering stem bearings were used on many Honda motorcycles in this bike size. When I finished this bearing research, I decided to find which Honda motos were involved. There is a web site that shows you which models a given part is used on. There are 371 bikes from 1981 through 2017 that use this bearing. Removing multi-year uses on a given model yields 105 bikes. List by model List by year |
My machinist friend pressed the stems out of the CRF150R and XR250R lower triples. He used a 12 ton press and had to use a propane torch to heat the aluminum lowers. The XR popped with a loud bang and then slid out in one motion. The CRF popped with a similar loud bang, but the stacked pieces shifted as he was pressing the stem out. The fender mounts sticking out the bottom are off-center from the stem and the spacer he was using shifted. Lesson learned - make sure any spacers are adjusted to be stable. On the continuation press (with re-heat), it took quite a bit of heat and pressure to get the stem sliding again. Another lesson learned - once it's moving, don't slow down.
Note - to avoid damaging the threaded top end of the stems during pressing, we did two things. We used a 1/4 inch thick by 2 inch wide round blank to sit on top of the stem to insure the pressure is applied equally. We also screwed on the upper nut first, then after snuggly mounting the lower spacer, stem, and upper blank in the press, we screwed the nut up to the blank, about one-half flat past just kissing. The ends of the stem are undamaged. This is more important when pressing the aluminum stem. (One-half flat means turn the nut so that the position of any flat on the nut moves half way to the next flat position.)
I'm chasing down reports of a difference in stem outside diameters between the two. My stems are nearly identical o.d.
CRF150R on the left, steel (and rusted on the end);
XR250R on the right, aluminum.
Lengths, mm: CRF150R = 225; XR250R = 235.
Pressing the XR250R stem into the CRF150R lower triple clamp.
Notice the bottom of the stem sticks out a bit (right side picture); the XR250R stem uses a snap ring where the CRF150R stem has none, instead, a larger end on the stem.
NOTE: Before pressing, the aluminum XR250R stem was cooled for 20 minutes in a double paper bag with two chunks of dry ice from the local Safeway. Marvin handled the stem wearing welder's gloves - see thumb in rightmost picture. Once pressed in, the entire lower clamp began to cool rapidly. Discard the dry ice safely - it is a dangerous hazard to pets and kids. It will vaporize safely in a double paper bag. Preferably in a loosely covered bucket in a safe area/structure.
From wikipedia: Dry ice sublimates at -78.5 °C (-109.3 °F) at Earth atmospheric pressures. This extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing (frostbite). While generally not very toxic, the outgassing from it can cause hypercapnia (abnormally elevated carbon dioxide levels in the blood) due to buildup in confined locations. See also SAFETY: Because it sublimes into large quantities of carbon dioxide gas, which could pose a danger of hypercapnia, dry ice should only be exposed to open air in a well-ventilated environment.
XR250R stem pressed into CRF150R lower triple and trial assembly.
This triple matches a set I have installed on one of my CRF230F bikes, top-to-bottom distance. I'll dismount the set currently on my 230F and mount this set to verify the fit.
Here is the modified triple clamp installed on one of my CRF230F bikes.
The lower steering stem nut that locks the upper bearing into the head pipe had plenty of thread-range to set initial torque. The upper nut that locks down the upper triple clamp has more than enough threads sticking up out the top. I did not have a new part #7 locking washer on the stem, but there are plenty of threads to accomodate it (see the XR250R parts list above).
Test rides confirm the XR stem is solidly in place and stable beyond my ability to find fault. Bearing drag remained as installed.
Success!
Some dry ice pix.
Soaking (!) the stem for a bearing install.
The temp after the bearing install: -2.7 F
It was -43 after the soaking, and before I installed the bearing!
Note the new bearing and the lower clamp have frosted up.
I didn't attempt to touch the assembly with my bare hands for 30 minutes.
Front brake hose
The stock CRF230F brake hose will not work with the CRF150R forks - it's too short and the places where it must be clamped are not suitable for clamping.
Having said that the stock 230F brake hose is too short, here's an example of what it looks like with the stock number plate (runnerng on TT). I consider this just barely workable. If you use a headlight, you'll need a longer brake hose.
Note that the stock 230F brake hose is not steel-braided. With these 150R forks, you're gonna be riding a bit harder and will want the better stopping performance of steel-braided over rubber hose.
For my first fork replacement (CR80R), I used a steel-braided brake hose that was left over from some project I had done years ago. I have no information about what bike this brake hose came off of.
When I installed CRF150R forks on my second CRF230F in 2010, the parts included:
2009 CRF250R front brake hose 45125-KRN-A31
This brake hose was long enough to clear the headlight and other items mounted on the triple clamps. Although the brake hose is not steel-braided, it works very good. Compared to the steel-braided hose I installed on my first CRF230F conversion, I can feel no difference.
After-market steel braided hose
I decided to check what an after-market steel-braided brake hose would cost. I took a spare brake hose from my stock that was almost exactly the length of the steel-braided hose of my first conversion and visited a motorcycle dealer. I found a match with the 2015 Suzuki RMZ 250. Then I looked for that brake hose in after-market sales on eBay and found one I liked for $51. When it arrived, I found it was a Galfer, quite a nice item - Frenokit Galfer FK003D412F. I chose a plain-jane standard color, but they offer many different colors of hose, bolts, and banjos.
I removed the CRF250R brake hose and installed this new one. It works great, slightly better than the CRF250R brake hose I removed.
Front brake hose clamp and 2 bolts
Regardless of which brake hose you choose, you should use the front brake hose clamp on the left side fork protector. It will clamp the brake hose so the hose will be out of the way and also positioned correctly for the caliper connection. The clamp is actually 2 parts and you mount it with 2 bolts. See the picture in the Triple clamps section above.
Steering stop
The stock CRF230F steering stops will not work with the CRF150R triple clamps. Reger Engineering sold an aluminum stop that is mounted to the front of the head pipe. My machinist friend made a few of these (see here). If you have the skills, you can make your own.
When fitting the steering stop, I first had to relocate the CDI from the front of the head pipe to a spot under the fuel tank. I moved the CDI box only (I set aside the bracket and rubber holder). I found it was easiest to disconnect the CDI and move it around until I found a spot that I liked, then connect the wiring, then use zip-ties to hold everything in place. I made sure that the plastic wiring connectors were not under any pressure from touching anything. There was adequate clearance from the fuel tank (I checked). While the fuel tank is off, consider whether you want to remove the key switch, and if so, do the rewiring now.
Front fender, bolts, and collars
If you use the stock CRF230F front fender and the forks are set with the tops even with the triple clamp top, AND you ride aggressively, chances are you will find that the front tire hits the front fender on hard landings. I used the 230F fender for a while on my first fork conversion, then tried the 150R fender. In the picture, the CRF230F fender is shown on top; the CRF150R fender below.
Circle-1. The large raised area between the 4 bolt holes is where the tire hits most often. On the 150R fender, this area is considerably lower and the tire will hit the fender less often. The difference between the two fenders in this area is about 3/8 inch more clearance with the 150R fender. To get even more clearance, you can lower the forks below the top of the triple clamps about 1/4 inch, and almost never hear the tire hit the fender. The wear marks in the 150R circle-1 attest to some bottoming. The bottoming happened before I lowered the forks.
Circle-2. Some incidental rubbing occurs at the rear of both fenders when mud builds up on the fender. The shorter 150R fender does not rub so much.
Circle-3. I noticed some rubbing on the 150R fender in this area which was caused by me using the wrong collars; I used some I found in my extra parts bin. When I switched to the correct ones (see below), the rubbing stopped. It only took me a year to notice...
4. The arc of the 150R fender is tighter than the 230F fender, and the end of the 150R fender rubs when mud builds up. You can just see where I trimmed the end of the 150R fender to reduce the mud build-up area. It helps. I should avoid riding in mud. Yeah, right.
I did mount an aftermarket universal-type fender, but it proved to be worse than either of these, so I finally settled on the 150R fender.
If you get the CRF150R fender, make sure to get the matching 4 bolts and 4 collars. They are different than the CRF230F bolts and collars. Actually, I see the collars are included with the fender SUB... so order FR FDR SUB and 4 bolts with washers.
Front tire and frame clearance
I am aware of a concern for the front tire hitting the frame at full fork compression. Several riders have sent emails asking if I had any difficulties with the front tire hitting the frame downtube when the forks are compressed to their minimum length, on a jump landing for instance. I don't recall ever even considering the possibility. When I bought and installed the complete Reger kit in 2006, I had no doubt that there would be no problems whatsoever. The kit was engineered and manufactured to such a high quality, I expected it would perform flawlessly. And it has. The subsequent install of a self-assembled and constructed kit has also been trouble free. But just to be on the safe side, I decided to have a look at my bikes.
A quick look under the front fenders reveals mud on the lower fenders and frame down tubes. If there was any rubbing, it would show in the residual dried mud. No trace that I could see.
(click pics for biggie pics)
I decided I needed more substantive proof, so I chose one bike and got busy. I removed the handlebars and popped the fork caps, then slid the wheel up against the bottom of the front fender.
The gap is 20/64 + plenty of room.
The question is, can the forks collapse any further if the fender wasn't there?
Next, I removed the fender, and jammed the wheel up as far as it would go. The gap measures 5/64.
The fork is collapsed the maximum amount possible. The lower castings on the inner fork tubes are tight against the bottoms of the outer fork tubes.
This condition can only occur when the front fender and fork caps are removed.
In this test, the fork springs are removed, and the fork caps are screwed into the tops of the forks (and incidentally onto the damper rods). The gap is 18/64 (2/64 less than the first test with the fender mounted)
The gap is larger than the test just above because fork travel is more limited. The inner fork tubes slide up until they hit the bottoms of the fork caps, which were removed in the test above.
Note - the tire is a used Pirelli MT43 2.75x21. The knobs are worn down about 1/3 off their new height. CRF150RB forks, axle, and triple clamp. Top of fork caps 1/4 inch below top of triple clamp. CRF230F front wheel.
As the first collapse picture above shows, the tire hits the fender 2/64 sooner than without the fender in this test.
Here is the CRF150R fender mounted permanently. The lower triple clamp fender mounting lugs have been trimmed about 1/8 inch.
The fender does not hit the frame.
The tire is in contact with the 4 fender mounting bolts and the rear of the fender.
The front of the tire does not hit the fender.
This picture shows the same contact as the similar picture above (3rd above). That picture had an extra washer on each of the 2 rear mounting bolts, so the angle is slightly different here, and the clearance to the frame is 1/64 less here; about 19/64 +.
I think this amount of fork collapse will not happen on a bike ridden moderately aggressively. As the forks are collapsed, the air pressure inside the forks rises dramatically, and I think the pressure will not be overcome except in the most extreme cases of bottoming.
This is the normal gap for my bike setup, and I'm ok with it.
Click the picture for a BIGGIE pic.
This gap was measured at 3/8 inch when the picture above was taken. As noted above, the forks can only collapse completely when the front fender and fork caps are removed. Put a zip tie on one of your own fork tubes and see how much travel you're really using.
If you have any doubts about your own forks/tire/frame dynamics, you should do your own checks when you assemble and mount the forks the first time. Before you install the fork springs, screw the fork caps on and check the clearance. Be sure, be safe!
Frame/forks geometry
This exposition was prompted by a ThumperTalk thread:
CRF150R Forks on a 230
jeffrow68 Posted 3/26/2017 at 08:33
Long story; tedious even. Hang in there.
In April of 2006, I switched to trials tires.
Front - IRC TR1 DOT 2.75 x 21
Rear - IRC TR011R 4.00 x 18
The front tire had a lower ride height than the stock and replacement knobbies I had been using.
The rear tire had a much higher ride height than the stock and replacement knobbies I had been using.
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Ride height for tires is the axle center line when the tire is mounted and inflated to normal operating pressure: larger diameter tires and larger cross section height tires have larger/higher ride heights. |
The effect of the tire changes was to steepen the fork angle (decrease rake) and speed up the front end response to turning input. In April when I switched to trials tires, I still had the stock fork setup. To compensate for the different tire sizes, I raised the triple clamps about 5/16", and the steering slowed down to tolerable. I coped with the remaining steering quickness by brute force: my upper body muscles developed adequately to act as a human steering damper, and I lived with the problem.
When I jumped on the CR80/85R and CRF150R bandwagon, I paid no attention to fork length, ride height, sag, and other measurements.
In August, 2006, I bolted on the CR85R Reger kit and rode the bike. The performance sold me. I was a believer. Done and done.
I was back to square one with the new forks at the top of the new triples. Again, I noticed quick steering, and again I raised the triple clamps, this time about 1/4" because I was being cautious about where to clamp the forks. Standard forks have a constant diameter for a very large range in the clamping area. USD forks have a much more restricted clamping area, and you are advised to stay within this smaller range to insure the forks don't slide within the triples.
Again, problem mostly solved, but my arms and shoulders still had to double as a human steering damper.
I rode with this problem for years, unwilling to switch to lower profile non-trials tires. Then, several years ago, I switched to Pirelli MT21 front and rear tires, and bike geometry changed again. To add to the confusion, I was now swapping rear suspension linkage to get the rear of the bike down. The result - tolerable but still quick front-end steering.
Alas, I was still stuck with quicker steering than I liked. AND, I was getting older and more demanding of greater riding comfort with less effort. So I had a thought, why not lower the rear end with a lower profile tire. But there are no low profile trails competition tires nor DOT trials-like tires. Then I stumbled upon the Shinko Trail Pro 255 Radial 110/90R18 M/C 61L, a DOT trials-like tire that I had tried several years earlier and rejected because of its peculiar penchant for following ruts by dropping into them. This tire is considerably smaller than a standard 4.00 trials tire. Note - also available in 120/90R18.
But now, I was using mousse instead of inner tubes, and thought that might make a difference. And it did. The Shinko still drops into ruts but not as readily as before when I was using inner tubes at low pressures. The traction on rocks and roots is not quite as good as with a competition trials tire but is more than adequate for this old coot. And now the bike's geometry is such that I am riding more relaxed with the slower, lower-effort steering.
For 2017, I'm going with a new tire/tube setup on my two CRF230F bikes:
Front Pirelli MT43 2.75-21 DOT
Front Nitro Mousse 80/100-90/90-21
Rear Shinko Trail Pro 255 Radial 110/90R-18 DOT
Rear Nitro Mousse 100/100-18
This setup is what I need for riding tight, technical, single-track trails in central Colorado mountains.
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One other item popped up during all this changing. I was bottoming the front fender on the front tire. One fix was to lower the triples, but that would quicken the steering, and was unacceptable. I then started looking into different front fenders. When I first installed the Reger fork kit, I installed the CR85R fender that came with the kit. Over the years I switched front fenders - first to the stock CRF230F fender, then to several aftermarket fenders. I discovered that all except the CR85R fender would rub the front tire occasionally. I later switched to the CRF150R front fender. Eventually, I switched my second CRF230F to the identical geometry CRF150R forks and CRF150R front fender. I was riding this CRF230F more aggressively and rubbing the front fender constantly. I shortened the fender mounts that stick down under the lower triple. I was only able to shorten the mounts about 1/8", but that actually took care of most of the rubbing. The final solution was to lower the forks below the top of the triple clamps about 1/4 inch. See Front fender for more fender rubbing information. |
In the ThumperTalk thread (CRF150R Forks on a 230), I see that 4strokeridertt has captured the essence of the issue: "The sag height is more important than the free length [of the forks] as the sag height is where you are when riding." And this number can be measured directly: the distance from the ground to the lowest point of the steering stem. As this number changes, so changes the steering. Smaller numbers indicate quicker steering; larger numbers indicate slower steering. There is no absolute reference number that everyone could adjust to. Variables that affect this number are front and rear axle heights (tire profile and tire pressure), fork spring rate (sag), fork length, shock linkage, shock spring rate, and shock preload.
Rear suspension changes will minimally affect this number, although they can change the frame geometry substantially. Be aware of this effect. Actually, measuring to a single point is a compromise. A better number would be the angle of some reference line through the frame with respect to a vertical or horizontal base line. But for fork geometry, this single measured line is a good working number to gauge front end changes.
For some, this information is well known. For me, it has been a slow process of learning, mostly by trial and error. I never connected all the dots until I read the ThumperTalk thread. BTW, I may not have discovered all there is to know in this area. Actually, you can bet on it. :-)
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Discussion is based on stock CRF230F forks and triple clamps; CR80/85R and CRF150R forks and triple clamps (modified to fit the CRF230F); no special frame mods; no aftermarket triple clamps.
CR80/85R axle, front wheel collars, and center support
You can use CR80/85 R or RB forks instead of the CRF150R forks mentioned most often herein. Reger Engineering made the "Wheel Spacers and Center Support" kit which replaced the front axle distance collar on a stock CRF230F front wheel. This allowed the smaller 12 mm CR80/85 axle to be used for CR80/85 fork conversions. See the picture and description of the CR85R axle and parts in the 'Left' column of the Front axle, axle nut, and washer section above. All other parts of the fork replacement description on this page apply. This is the only place where the two fork replacements differ.
I had read on ThumperTalk in several posts that an easier (and cheaper) conversion would be to replace the stock CRF230F wheel bearings with 12 mm i.d. bearings. I have a kit with two SKF 12x35x11 bearings and two 12 mm axle spacers for sale HERE.
Parts list; prices Aug 2016
| Forks | Purchase from Honda dealer, eBay, or other | New about $1,200; used $300-$500 |
| Fork springs | Factory Connection, Race Tech, or eBay | New about $100 |
| Fork suspension fluid | Purchase from Honda dealer or other | $8-$30 |
| Fork protectors, left and right Fork protector bolts x6 |
Purchase from Honda dealer Right 51610-GBF-680ZB or 51610-KSE-A50 Left 51620-GBF-680ZB or 51620-KSE-A50 Bolt x6 90113-MAC-780 |
New protectors $62-$76 for both New bolts about $14 for 6 |
| Caliper bracket kit | See here. | $125 |
| Heli-coil | Shop work; see here. | Nuts and bolts alternative - about $10 |
| Front axle, axle nut, and washer Axle collars are included in the caliper bracket kit. |
Purchase from Honda dealer Axle 44301-KSE-000 Nut (14mm) 90305-197-013 Washer (15mm) 90510-KY1-000 |
New axle about $17 New nut about $4 New washer about $2 |
| Triple clamps |
Purchase from Honda dealer, eBay, or other On eBay, often the triple clamps come with the forks. |
New about $310; used about $100 |
| Lower triple clamp modification | Shop work; see here. | Cost depends on which method you choose. |
| Front brake hose |
Purchase from Honda dealer, eBay, or other 2009 CRF250R front brake hose 45125-KRN-A31 Frenokit Galfer FK003D412F Suzuki RMZ250 04-15 |
New about $55; used about $25 |
| Front brake hose clamp and 2 bolts |
Purchase from Honda dealer Clamp A and B 45461-GBF-J00 45462-GBF-J00 Bolt x2 90113-KZ3-000 |
New clamps about $12 for both New bolts about $4 for 2 |
| Steering stop | See here. | $35 |
| Front fender, bolts, and collars |
Purchase from Honda dealer, eBay, or other Fender assy - fender and collars 61110-KSE-000 Bolt (6x16) x4 93404-06016-08 |
New fender assy about $41 New bolts with washers about $3 for 4 |
| Custom SKF bearings CR80/85R axle, wheel collars, and center support |
See here. Reger Engineering "Wheel Spacers and Center Support" kit Try eBay |
$65 - - |
All Honda part numbers in the preceding table are for various years of CRF150R/RB models (13 numbers).
Some of the part numbers are also found on various years of CR80R/RB and CR85R/RB models (6 of the 13).
Verify part numbers before ordering:
DiscountHondaParts.com You can order parts by entering the part number in a search box.
PartsFish.com You can look a part number up (search box) and get a list of where it's used, then order.
Fork Modification - Modifying stock forks
Stay tuned...
