The ultimate street and trail bike

Ok so its been a while since ive been on here. Before i aske my question let me start from the begining.

I picked up and old 2stroke dirt bike and had nothing but trouble with it its a giant lemon basically thats sucked up more money than it was worth. Last time i got it on a trail i blew the clutches out of it and that was the last straw for me. So began my search for the perfect multi terrain bike for my riding style. 2strokes where out for many reasons the biggest of which is that they just dont suit my riding style. So i narrowed it down to a 4stroke engine. I could get another dirt bike engine. But i wanted more low end grunt yet enough top end to be streetable if i made it road legal as my long term plans where. So i needed something 250cc and up. More the better for street use. But theres an upper limit for reasonable offroad capability without killing myself. I limited my search to a 250cc- 650cc max. Unfortunately dirt bike and dual sport motors are going for stupid prices around here. A klr650 for example goes for over a grand. Just the motor.

My search took a new and interesting turn, im building this so why not a street engine? After doing some research ( a lot more than i actually expected) i came across the advriders forum on "frankenbikes". These are a collection of hand built dual sports using the best of both street bike and dirt bikes and matching them into the ultimate machine for each individual.

I found my inspiration and by pure chance came across the perfect donor. A 1982 yamaha xs650 bobber project with a rebuilt engine and a good title for $200! Ill include a photo if i can figure it out of my inspiration build. The goal if you will.

But now im left with some questions and i remember the mass of knowledge on yamaha motorcycles from the 80s on this forum. So i bow down now and humbley ask for your assistance on this project.

First dirt bike wheels or street wheels? Spokes have a purpose off road but could i get away with mag wheels and dirt tires? Wide 16in dirt tires are hard to find if not impossible. So could i use a front wheel? Would the rotor holes possibly line up with sprocket holes? 19in tires are easy to come by in any dirt tire. I know ill probably have to make axle spacers anyways if i dont use the dirt bike wheel with the donor swingarm.

Gearing? Any ideas on where i should start with for sprocket sizes for something like this? Ive seen conversion sprockets for the xs650 to upgrade chain size so even going to the bigger chain shouldnt be an issue but i dont want a 50mph dog that cant keep the front wheel down or a drag bike with no low end.

Any other ideas or suggestions are welcome but remember that this is being done over time on a budget for now. Oh and the dirt bike is a 92 wr200. So im dubbing this project the wr650 lol.

 

This link is to the inspiration... Its the blue bike. Page 22 if it takes tou to the beginning
http://advrider.com/index.php?threads/converted-to-dual-sport-post-pics.330726/page-22


This is a link to a very similar build inprogress
http://advrider.com/index.php?threads/just-another-650-adv-bike.843072/

 

DO it.

 

Do it. But, you may want to consider the advice of the build thread though. He suggests adapting the XS motor to a YZ490 frame is probably easier than adapting monoshock suspension to the XS frame.
In which case the WR200R is likely not a good candidate.

 

Well thats the rub the wr200 frame i have already. Everything i need is there. Im actually following 2 very similar builds on advriders forums using crf frames and old kawasaki twin motors. The mono shock isnt the hard part per se its the dogbone for the monoshock that seems to give everyone fits. Mostly because they want to stick with aluminum. I think ill probably swap it for a fairly easily fabbed steel one. That bit of weight wont make a difference at this point. Its gonna be a heavy pig either way for a dirt bike though not bad for a dual sport

 

Plus finding a yz490 frame..... With a title.... That i can get street legal.... Whereas the xs frame has a good title.

 

I'm curious to hear the problems you've had with your WR200? I rode one from 1994 - 2005, pretty solid performer although not much power and undersprung suspension.

 

Just didnt have the power i needed until i put a bunch of time in it. It was fine for mostly level trail riding but had a horrible time with any sort of hills of a minor grade. I was able to get a bit more out of it by rejetting removing the powervalve taking the packing from the muffler and uping the rear sprocket. But its been a lemon basically since i got it. Last ride i blew the clutches out of it and instead of dumping money in a motor im not happy with my plan is to mash the suspension that i actually like with a motor i know will perform everything i ask it to and then some. Being street legal at the end of it is only a bonus

 

There was something else wrong with it then, I've ridden them and they have no problems with hills or terrain of any grade, they're a very capable off road bike

 

That was the reason i picked it up. It had a fresh topend and the compression check i did confirmed that. But my theory now is that if im going to sink a couple hundred into rebuilding the entire motor i might as well build the bike i want. I should still only have a few hundred in it this way. The xs650 was only 200bucks because it was still stripped down. That one i know for a fact has a fresh engine as i was there when it was being done. Itll also have the added benefit of being road legal without much modification past what is already planned and itll to it comfortably. The weight should be close to a klr650 when im done probably a bit less.

 

Following with interest. My other bike is a '96 NX650 Dominator, love doing overnight trips up in the hills.

 

reality check
http://altoona.craigslist.org/mcy/5802865511.html
do you want to ride or be a bike builder?

 

I cant do both? Maybe my interest in bikes is such that i enhoy working on them as much as riding them. Plus im 260lbs. That dr350 when new couldnt do highway speeds with me on it. The old xs650 could easily take me to 100mph and cruze there on its stock setup. And should be able to do 65/70 mph all day even when im done with it. Also winter is coming. I have more than a few months for this build. The swing arm from the wr200 is within millimeters of being a perfect fit (slightly narrower so a spacer will be needed but no major machining) also the triple tree tube is the same length and with except for the bearing race seats which ive already removed from the wr200 and will be transplanting onto the xs frame. At this point the hardest part of the build is going to be fabing up the rear monoshock mount. But since the xs frame was already hardtailed when i got it i have a clean slate for whatever i need to do. When this bike is finished it should be able to out perform a klr650 on road and off road and have just as much power as a newer ktm 350sxf on the trails. Sure itll be to heavy to take major jumps properly but thats never been my goal. As far as riding goes though... I have a fully functional 82 xj650 for the street. This is part my ocd at not having what i want and need in a dual sport and part plaything just because i can. This bike will be mine and mine alone. Itll be nearly if not one of a kind.

 

If you're mechanically inclined a monshock shouldn't be a problem. I just finished mine the other day on an xj550 and I had to fit a monoshock while also wanting to lower the rear. Created a few problems trying to get it low butt I'd imagine if you're running dualsport, you'll want a slightly higher rear anyways. Do the math and see where it gets you, I ended up with the perfect amounts of sag and travel so anything's possible, it's just steel.

 

Oh i know its possible thats just going to be the hardest part of the fab work i think figuring out the geometry for it so i get the full travel. I have to do some more research on that part of it yet but im in no hurry as i have all winter to play with it

 

An update on the frame work.

So far the most interesting bit is that the wr200 swingarm is the exact same size as the factory xs650 swing arm at the mounting point including the axle diameter allowing me to use the factory xs axle and avoid extra fab work in that area. Front forks triple tree tube was the same length between bikes but they used different bearings. The xs650 used regular ball bearings. The wr200 used tapered roller bearings. Because of this the tapered roller bearing races had to be cut from the wr200 frame and welded in place of the regular ball bearing races on the xs650 frame to allow the front suspension to mount properly.
The xs 650 frame had already been modified to make it a hard tail so the rear section of frame was previously removed. Because of this i took the rear section of the frame from the wr200 and spliced it into the xs650 frame. This allowed me to use the upper shock mount from the wr200 on the new xs frame. I have to make a new left side frame support as the original from the xs650 interfered with the wr200 rear monoshock and had to be removed. Otherwise even though its a little tall right now things are finally coming along. I was hoping to have the motor in and be wiring it up but finacial issues kept me from getting that far yet. The bike should drop a couple inches once the motor is put into place which should make the height just about right for what i was shooting for.

 

You welded the bearing races? No bueno. Bearing races are always a press-fit. Welding will distort them and cause accelerated wear (and funny handling).
Go to your local bearing house, or All Balls, and get a new set of bearings to match the ID of the stem and the ID of the neck. Use a Dremel or die-grinder to remove the welded-in bearings and carefully clean up the steering head.

 

No no not the races the race cups. The part of the tube the bearing races actually sit in. Took some time to get them level and square but they welded up nice the races fit in just like they should and everything turns smooth without any binding even with my full weight on it.

 

Whew!! Good for that. In the future, bearings come in a huge variety of sizes; it's unusual to not find a bearing that is compatable with a stem swap into a different neck. Saves a lot of work.

 

I probably couldve found something but the tapered rollers are better bearings than the xs frames original ball bearing design for this application. It also keeps me from having to remember what those special bearings are. Now i can just pick up a set of wr200 stem bearings and be golden in the future.