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Montesa 4RT - Modifications
December 17, 2016 version

 Introduction 

 Modifications 

Rick's Home Page

Click pictures to supersize.



Parts are in, back to work.

                      Alphabetical table of contents  

Bags 
Bank sensor 
Crankcase vent 
Cylinder head vent 
Footpeg relocation and large footpegs 16/12/17
Fork bleeders 
Fork seal protectors 
Front fender 
Fuel 
Gearing/Sprockets 
Handlebar pad 
Handlebar, grips, and handguards 
Head light, taillight, brake light, horn, mirror 
Hour - Tach Meter 
Kickstand 
Manufacturer stickers and imprints 
Odometer/speedometer 
Rear fender 
Seat 
Shifter bolt 
Spark arrestor 
Tires 
Water bottle 
Weigh-in 
Date in red is date of most recent change; yy/mm/dd.

Trials To Trails

I looked at the pictures and specs of the new Montesa 4Ride and compared them to the 4RT. After several weeks of cogitation, I decided to buy the 4RT and modify it slightly so I could enjoy it on trails here in central Colorado. I'm naming the project 'TrialsToTrails'.

I've divided my mods into two major sections:

Licensing mods - what it takes to be street-legal in Colorado. This includes equipment required by Colorado state law, as defined on state form DR 2686 (06/18/15) - Certification of Equipment Compliance for Motorcycles. I'm also adding a spark arrester, which is not called out on DR 2686 but is required by the US Forest Service and Bureau of Land Management when riding on public lands.

Trail riding mods - adding trail riding ability and comfort. This includes items such as suitable fuel capacity, handlebar mods for comfort, and footpeg mods as almost a matter of necessity, as well as other mods I find very useful on trail bikes.

Besides these mods, I will be giving the 4Ride parts catalog a close look to see what 4Ride parts can be fitted to the 4RT and that would be helpful in my project. The fuel tank is one such part that I very much want to try.

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Weigh-in

I like to weigh new bikes when I get them home from the dealer before I add, remove, or change anything.
My scale is a Walmart bathroom mid-price, not too accurate, but it allows me to compare bike weights one-to-another.

12/12/15 stock with all fluids except gas - 164 pounds.
   This is only the second bike I've ever owned that weighed less than I do.
   The first one was a Honda 90 step-through in 1964 or so.

12/12/15 added new seat plus storage area, with all fluids except gas - 169 pounds.


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Handlebar pad

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The first and easiest mod, by far, is the removal of the handlebar pad. Unhook, and it's done.

I'll be installing new handlebars and have no need for this protective pad. Besides, at 47 grams, it gives me some headroom when doing other mods, where the new parts may weigh more than what they are replacing. 47 grams goes a long way.



Licensing mods - what it takes to be street-legal in Colorado.

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Head light, taillight, brake light, horn, mirror

I decided that the best way to add electrical components that are required for street-legal licensing was to look at the schematic for the Euro street-legal 4RTs and add my new electrical components in a similar manner. All of my electrical additions are on a single branch circuit which is activated by an on/off switch located on the handlebars. I call this switch the master switch, but it's just a master for my additions, not the whole bike. Normal trail riding does not require my electrical add-ons to be active, so I will usually be riding with the master switch in the off position. When I come to a county road or state highway, I will activate my electrical add-ons with the master switch.

Just as the street-legal 4RTs and 300RRs do not use a battery to power lights and horn, my modified 4RT will also not require a battery to power the street-legal electronics that I am installing.

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For reference, here is a Euro street-legal schematic.
Click to supersize.

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The US model schematic with the red (+12V approx) and green (GND) take-off points marked. For red, I will use the currently unused red pin in the 4P connector. For green, I will use the ground wire collection connector.
Click to supersize.

The arrows point to the take-off points.

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I'm not showing the schematic for my add-ons; it's very simple and easily derived by others. Riders will probably want to have their own electrical mods custom designed for their specific needs.

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Here is my wiring loom; simple and direct. The front section goes to the handlebars and has connections for the master switch, headlight, and horn. This section is routed along the frame up to the triple clamps and then the handlebars. Note - turn signals are not required for street-legal registration in Colorado.

The rear section of the loom goes to the taillight, with a pickup at the rear brake switch, and has connections for the taillight and brake light. This section is routed through the rear fender stiffener/flare and stock rear fender sandwich (see Rear fender).

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Here are the mounted handlebar switches; they're not connected yet.

1. Lights off/lo/hi switch and kill button.

2. Horn button. Note - I may replace this with a more conveniently located button.

3. Dual map switch.

4. Master switch.

I found a smallish LED headlight on eBay; made in China.
The LED taillight/brake light, horn, and mirror are on hand.
A fuse holder is also on hand.

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Headlight test fit.


Although I've purchased all of these parts from various sources and fabricated my own wiring harness, you should know that the Honda street legal parts and sub harnesses that are on the Euro 4RTs are available for you to purchase instead. I estimate that you will pay 2-3 times what I have, but you will do a lot less leg-work chasing down parts and you won't have to learn how to design electrical circuits. You'll save time installing everything also. Lastly, if you're in Europe or anywhere else that sells the street legal 4RTs, you can just buy one of them as a starting point.

Head light: Red motorcycle Streetfighter headlight LED - about $21.  oncemore2015 on eBay
BikeMaster mini LED taillight with license plate light - about $22.  Powersport Parts on Amazon
Hydraulic brake switch, Brembo brakes - about $15.  Rocky Mountain ATV MC
Trail Tech (040-HBS-05) three position light switch plus kill switch - about $27.  Amazon
Master switch: Trail Tech (040-HBS-01) two position light switch - about $20.  Amazon
TOOGOO universal motorcycle horn - about $4.  Amazon
Horn button - about $33.  HighwayDirtBikes
Mirror - about $5.  Local auto parts store.




Trail riding mods.

The rest of the mods are related to using the 4RT as a trail bike. Yes, I'm going to waste the excellent trials design and features and I'm going to convert the 4RT to a trail bike that I can use for riding tight single-track trails in central Colorado. This is a project just for me, not necessarily for others. Many will think it's a waste to ruin such a fine trials bike, but I look at it as using exactly those features that make it so trials-worthy to re-cast it into a trail-worthy moto. The extreme light weight of the 4RT is the primary reason for starting with it as a base. The ability to ride virtually any trail obstacle with ease only adds to the allure.

Note - this is not a dual-sport conversion. I've had to make the 4RT street-legal by necessity; I must be able to ride short distances of highways and byways that require street licensing. I've done the minimum here; this is not in any way a dual-sport bike.

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Spark arrestor

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I saw a trick lookin' aluminum spark arrestor while cruising for parts and jumped right on it. It's a teensy bit loose, but the 3 set screws seem up to the job.

I'll through-drill it on one side and put a split pin in for insurance.

Aluminum Trials Spark Arrestor, size 1.125" - about $65.  Trials Superstore


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Handlebar, grips, and handguards

I like Pro Taper SE handlebars and will install a set, cut to my preferred width. Spider SLR grips for my wide hands are a must. I like the feel, too. I'll be foregoing aluminum/plastic handguards and installing an all-plastic setup to save weight.
CRF250L Handlebar, grips, and handguards

Preliminary look at the handlebar installation; final pictures after the holidays when all parts are installed.

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The left picture is looking at the front of the bike; the right picture is the cockpit view.
The Rox Risers are also installed.

The stock handlebar plus left grip weighs 697 g and the Pro Taper SE plus left grip weighs 841 g, thus adding 144g.

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The Rox Risers moved the handlebar back 15 mm / .6" and up 30 mm / 1.2". The new handlebar width and position necessitated relocating the throttle cable and the clutch and front brake hydraulic lines. They work best in a more conventional layout than the stock layout. The stock layout seems very wrong to me, cables and lines running vertically and above the handlebars. This would never do for trail riding, where a high arcing cable/line can easily get snagged.

The stock handlebar clamps weigh 116 g and the Rox Risers weigh 306 g, thus adding 190 g.

Pro-Taper SE 7/8" Handlebar CR High Bend Platinum Grey - about $63.  Rocky Mountain ATV MC
Spider Grips SLR Open End Grips Red/Black - about $17.  Rocky Mountain ATV MC
Acerbis Rally III Handguards - about $80.  Rocky Mountain ATV MC
PMB FASTWAY threaded bar inserts - about $21.  seismiccycles on eBay


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Seat

The next mod is to install the supplementary seat and under-seat storage area. The two pieces, plus hardware, weigh 4 pounds 13 ounces - I'll call it 5 pounds. I removed 4 bolts from the bike, placed the seat base (includes storage area) into position and secured it with two metal mounts and 2 long bolts at the front and 2 spacers and bolts at the rear sides. The seat clicked into place. All done - easy peasy.

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Fuel

The fuel tank holds 1.9 liters (.5 gal), and that isn't enough fuel for my normal trail ride. I had several options in mind (see below), but after thinking about it, I decided to go with the HM seat/fuel tank combo. I found TrialMotor, a shop in Lousã, Portugal listed the seat on their on-line shop, but after ordering it, I was advised that HM would be making a new model that would be available SOON. New models often take a while to get into production, but I waited patiently, and the seat finally arrived. TrialMotor owner Filipe Paiva was my contact for the duration of the transaction, and he kept me well-informed of the several delays and eventual shipment. He was always positive and I never doubted that an HM seat would eventually be mine.

Here's a trial fit; looks great.
The seat/tank combo holds about 2.2 liters of fuel.

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I also purchased a small fuel tank that fits on the front forks, behind the light.

Hebo HI8065 fuel tank, 1.1 liter / 1.16 qt


Stock tank + seat/tank + fork tank
1.9 + 2.2 + 1.1 = 5.2 liters = 1.37 gal = about 55 miles (40 MPG)


I'll try to order the 4Ride tank (4.4 liters) which is now available.


4Ride tank + seat/tank + fork tank
4.4 + 2.2 + 1.1 = 7.7 liters = 2 gal = about 80 miles (40 MPG)


Here are some options I considered, but did not use for various reasons.

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Carry  Touratech 2 Liter Spare Fuel Canisters  under the seat.

Won't work - not enough room. Here are two 500 ml bottles in the storage area, and they barely fit. Not even one of the 2 liter Touratech canisters fit because of their shape.

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Carry the TT canisters in the Mojavi - doable, but awkward.

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Carry a bladder under the seat.

Here is a plastic bag of water tucked into the storage area; lottsa room.

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2 Litre Touring Bladder from "Liquid Containment" in Australia.

The bladder material is so stiff, it cannot be bent to fit into the supplementary under-seat storage area. Too bad; the bladder looks cool. I may fasten it to the rear fender for longer rides. 2 liters is about 20 more miles of riding.


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Cylinder head vent

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I replaced the catch bottle that was in the steering head area with a Uni filter. Now the cylinder head will vent to the open air. The original Honda design vents into the airbox, in the clean air flow after the air filter then into the throttle body. I've had throttle bodies get very dirty with this type of venting; thus my redesign.

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The removed bottle and one hose are shown here (upper); I re-used the shorter hose to hook up the Uni filter (lower).

The small plastic piece (nipple) with the red vinyl cap goes into the front of the airbox. When I tried to pull the hose off of it when it was still in the airbox, the whole nipple came out. I managed to get it back into the airbox easily; even added some silicon sealant:

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Uni breather filter UP121 - about $12.  Amazon


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Crankcase vent and bank sensor

busy I replaced the crankcase vent hose with a shorter hose and Uni filter. To make room for the filter, I removed the bank sensor. I had to remove the side panel and muffler to get to the sensor - it still wasn't easy. I jumpered the end connector then covered it with Kydex and white Gaffers tape.

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Uni breather filter UP121 - about $12.  Amazon


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Gearing/sprockets

I looked at the gearing specs for the 4Ride to see what Honda/Montesa thought would be suitable for road and trail use. The 4Ride first through fifth gears have the same spread as the 4RT second through fifth. The overall gearbox width is 2.93 compared to the 4RT 3.44. This is not good for dirt road use.

I decided that keeping the stock 4RT tranny gearing and changing the sprockets was the better course of action. I wanted to put an 11T front sprocket on, but no one sells anything other than a 9T and 10T (stock). So I ordered a 38T rear sprocket, 3 less than the stock 41T, until I find a front 11T.

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The chart shows speed for all gears at various RPMs.
Speed in 5th gear at 8000 RPM is raised from 59.1 to 63.7 MPH.

Max RPM should probably be kept under 8K...
7K would yield about 55 MPH; plenty fast for short highway sections.

I installed the 38T rear sprocket and had to move the axle back to take up the chain slack. I'm at the last position on the axle cams and still have some chain slack, and expect more as the chain wears. I ordered aftermarket cams that are slightly larger than stock but I can ride the 4RT while I wait. Take off in first gear is more trail-like and less trials-like, and the lower gears last longer, if you catch my drift.

I do not like the chain tensioner, but it is necessary because of the frame design near the swingarm pivot. A solution is possible, but would be expensive and time-consuming. What was Honda thinking? Grrrr.

Jitsie 38T rear sprocket - about $50.  LewisportUSA


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Footpeg relocation and large footpegs

I asked a local machinist guru to design and fabricate new footpeg brackets which will enhance trail riding comfort. The new brackets place the footpegs further forward than the stock location and allow me to shift without raising my foot off of the footpeg. The new location is very similar to conventional motorcycle footpeg location.

Outstanding!
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Just beautiful. The shifter distance fits my foot perfectly.
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LATEST - Almost final.
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Plans are afoot to extend the brake pedal.
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First cut at the brake pedal; just needs a few tweaks.
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Mounted.    Most Excellent.
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Besides relocating the footpegs, I also made them larger. I suffer from instep fatigue when I ride for longer than about 5 hours. I use ortho inserts in my riding boots, but that doesn't completely solve the problem. Some time ago, I discovered that larger footpegs provided a great deal of relief. So I went looking for larger footpegs for the 4RT. Although I bought a set of RQ footpegs, I was not satisfied with the size.

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I slipped a set of Works Connection footpeg wideners on the stock footpegs. They look great. A friend welded them for me.


About the Works Connection footpeg wideners.

When I had my 2009 WR250R I had a need to widen the footpegs, just like I'm needing on the 4RT now. I had used a footpeg widening product on several bikes I owned in the 70s, and I went looking for them on the interweb. Lo and behold, I found some Works Connection footpeg wideners. They looked just like the ones I used on my bikes from the '70s with the wimpy footpegs. Exactly like 'em.

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They come in many widths so they fit virtually any footpeg out there. I ordered a set of 1 1/2" for my WRR and a set of 1 5/8" for my CRF230F. Actually, I ordered several of each.

When they arrived, I noticed the 1 1/2" wideners didn't fit the WRR footpegs exactly. I used a grinder to take off 1/32" or so on the inside of the spacer and then they fit just fine. The local welding shop charged me $15 to weld the wideners on and walla, wide footpegs.

The wideners add 1/2" to the width and about 1/4" to the length, and that is just about right for my small 8 1/2 foot.

In the picture, the upper two WRR footpegs have the wideners welded on and I'm showing a top and bottom view. A stock footpeg is just below for comparison. The two wideners are very simple, with just an extra strip of spacer welded to the inside edge to get the teeth away from the stock teeth. Click the picture to see the details up close.

Works Connection footpeg wideners - about $30 per set.  MXSouth and Works Connection


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Front fender

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I raised the front fender (for mud clearance) with these trick spacers from V-Mar.
They added 31 g, not as much as I thought they'd add.

Fender spacer set - about $15.  V-Mar Racing


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Rear fender

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Here's a very nice road conversion effort from a rider in Belgium.

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Another very clean looking conversion.

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I now have one of these.

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If I can't track down any of the fenders above, I may end up with one of these.


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Shifter bolt

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The stock bolt on the shifter can come loose and then the shifter starts wearing the splines on the shifter itself and possibly on the shift shaft. I always install a longer bolt and a locking nut on the extended length. That sucker will never come loose. It does add a little extra weight, but it's more than worth it.


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Water bottle - I don't use a hydration pack; can't stand weight on my back and having my shoulders pulled back. I'll mount a water bottle on the front handlebars.


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Fork bleed valves - A must-do mod. There are no air bleed screws on the stock fork caps, so I may have to machine something up.
Fork bleeders


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Fork seal protectors - Reliability/protection mod.
Fork seal protectors


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Hour - Tach Meter

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I've been putting Hour-Tach Meters on my new bikes. It's handy to be able to check RPMs and the hour meter is great for judging maintenance needs.

No power required; you wrap a wire around the spark plug lead. It's magic.

Trail Tech Hour-Tach Meter - about $34.  Amazon


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Odometer/speedometer - I'll be installing a Trail Tech Endurance II odometer/speedometer. Besides odometer/speedometer functions, this unit has average and maximum speed, and also trip and accumulated wheel time (time while bike is moving), all of which are of some interest to me for trail stats.


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Kickstand

I found a way to eliminate the auto-retract feature of the kickstand. Pictures soon.


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Bags, tools, et al - Gotta carry tools, rain gear, snacks. The 4RT doesn't look to have many places to carry these items, so I'll probably add a Mojavi saddlebag on the back. I'm reserving the under-seat storage area for extra fuel.
MoJavi saddlebags

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Here's another possibility - I like the color, it almost matches.


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Tires - Install a TechnoMousse in the front tire. The rear is good to go; it's a tubeless.

Forum info:   Dunlop Trials Tyre - Trials Central

Front tire markings when new.

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D803FGP

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80/100-21    M/C 51M

All markings, starting at DUNLOP and running clockwise:

Right side of tire.*
DUNLOP
TUBE TYPE
B
E11    75R-003463
MADE IN JAPAN
SUMITOMO RUBBER INDUSTRIES, LTD.
MST
D803FGP
80/100-21    M/C 51M
FOR TRIAL COMPETITION USE ONLY


Left side of tire.*
DUNLOP
TUBE TYPE
LOAD RANGE B
EUEK X2015
MAX. LOAD 195 kg (430 LBS)
AT 230 kPa (33 PSI) COLD
PLIES
   TREAD 2 NYLON
   SIDEWALL 2 NYLON
D803FGP
1A5220
5732
80/100-21    M/C 51M
FOR TRIAL COMPETITION USE ONLY


* There are no tire mounting directional markings on the tires, so there are no left or right sides. This left and right side text corresponds to the text on the left and right sides of my tires as mounted when my 4RT was new.

Rear tire markings when new.

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D803GP

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120/100R18    M/C 68M

All markings, starting at DUNLOP and running clockwise:

Right side of tire.*
DUNLOP
TUBELESS
B
E11    75R-003462
MADE IN JAPAN
SUMITOMO RUBBER INDUSTRIES, LTD.
MST
D803GP
RADIAL
120/100R18    M/C 68M
FOR TRIAL COMPETITION USE ONLY


Left side of tire.*
DUNLOP
TUBELESS
LOAD RANGE B
EUEF X2015
MAX. LOAD 315 kg (694 LBS)
AT 230 kPa (33 PSI) COLD
PLIES
   TREAD 2 POLYESTER + NYLON
   SIDEWALL 2 POLYESTER
D803GP
1A5318
RADIAL
5733
120/100R18    M/C 68M
FOR TRIAL COMPETITION USE ONLY

Front rim.

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MORAD SPAIN  1.60 X 21"  10LCD  32T  10/8/15  E  DOT

Rear rim.

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MORAD SPAIN  2.15 X 18"  2H  32T  10CD  22/7/15  E  DOT



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Manufacturer stickers and imprints

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Fuel tank.
Owner's Manual legend:
Caution label
For your protection always wear your helmet while riding.
Read Owner's Manual carefully.
Use premium unleaded gasoline only.

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Chain guard.
Owner's Manual legend:
Keep chain adjusted and lubricated
25-35 mm (1.0 - 1.4 in)
Read Owner's Manual.
 
 
 
 
 


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Storage area.
I guess we won't be doubling, Chad.

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Rear fender, hidden under the fender.


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ECU

"3ED" is the model designation for the US bike.
This matches the model number shown in the Owner's Manual.
The parts manual shows parts for 4 different models; pay attention.


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Miscellaneous stickers scattered around the bike; sample selection.
Gotta save weight, so off they come.


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Frame. This one stays; looks nice to me.

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Steering tube.


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Left fork.

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Rear sprocket.


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Radiator cap.
I can't quite make out the Japanese... I think it says hot-hot-hot.


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Engine serial number.


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17 character VIN struck into the metal surface of the steering tube.
My bike's serial number (in these pictures) has been rendered illegible.

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Vehicle identification plate affixed to the steering tube.
 



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