Montesa 4RT - Modifications
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Click pictures to supersize.
Parts are in, back to work.
Alphabetical table of contents
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.
Weigh-in
I like to weigh new bikes when I get them home from the dealer before I add, remove, or change anything.
12/12/15 stock with all fluids except gas - 164 pounds.
12/12/15 added new seat plus storage area, with all fluids except gas - 169 pounds. |
Licensing mods - what it takes to be street-legal in Colorado.
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.
The arrows point to the take-off points. 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.
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).
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. 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 |
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.
Spark arrestor
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 |
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. Preliminary look at the handlebar installation; final pictures after the holidays when all parts are installed.
The left picture is looking at the front of the bike; the right picture is the cockpit view. The stock handlebar plus left grip weighs 697 g and the Pro Taper SE plus left grip weighs 841 g, thus adding 144g.
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 |
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.
Hebo HI8065 fuel tank, 1.1 liter / 1.16 qt
I'll try to order the 4Ride tank (4.4 liters) which is now available. Here are some options I considered, but did not use for various reasons.
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.
Here is a plastic bag of water tucked into the storage area; lottsa room.
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. |
Cylinder head vent
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: Uni breather filter UP121 - about $12. Amazon |
Crankcase vent and bank sensor
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. Uni breather filter UP121 - about $12. Amazon |
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.
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 |
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.
Just beautiful. The shifter distance fits my foot perfectly.
Plans are afoot to extend the brake pedal.
First cut at the brake pedal; just needs a few tweaks.
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.
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.
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 |
Front fender
Fender spacer set - about $15. V-Mar Racing |
Rear fender
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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. |
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 seal protectors - Reliability/protection mod. |
Hour - Tach Meter
No power required; you wrap a wire around the spark plug lead. It's magic.
Trail Tech Hour-Tach Meter - about $34. Amazon |
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. |
Kickstand I found a way to eliminate the auto-retract feature of the kickstand. Pictures soon. |
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.
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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
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