Flat Track 200X Questions

[Levithan]

Hi guys, i just had a few questions about how to set up a bike for mx/ flat track. I have a 85 200X roller and i would like to know what i need to do as far as the suspension is concerned. All the flat track bikes ive seen look lower than a stock 200x. Is this true? Also, would a +2 axle be enough for this bike? What size tires should i put on it. Then, what sorts of reliable engine mods should i put into this bike. The engine that came with the bike came with a box of parts, and there is a piston in there that I believe is a 12:1 ratio. Also, there is a racing cam in there as well, with what appears to be some slight etching where the bearing rides. So I am pretty unsure about that. I also have a supertrapp exhaust with the disc setup, so that would be going on there as well. So what do you guys think? I would like to make a reliable racer, with good mid range torque and a decent top end. Well, let me know what you guys think about this. Either way, I am very serious about setting up a good MX bike. After seeing all of those pics of those guys racing flat track recently, i think ive caught the bug!

[SWIGIN]

id go with at least a plus 4 axle and if your useing the stock wheels then go plus 6

12-1 is a great race piston...but you WILL need race fuel to go with it

[Billy Golightly]

You'll probably want a +4 rear axle, some type of custom rear suspension linkage to get it lower in the back (or a shorter shock) mod the front forks to get shorter in the front. On my 250R I'm running a custom 10inch front wheel with a Duro "Scorcher" tire. And I'm using Burris brand 16inch rear tires, which would probably work great on the 200x. You cant buy these from Burris anymore but American Racer has the exact same tires. They are kinda spendy though (But all tires for this type of racing are)

[Levithan]

What if I run wheel spacers? Where can i purchase those? Also, do i have to get a stroker setup for a 12:1? This engine looks as if the high comp piston may have impacted the top of the head where the valves are. What would cause this? Any other sugguestions are appreciated, thanks!

[Billy Golightly]

Hmmm. Loose main or connecting rod bearing that got a little bit to much play in it? If your really wanting to go big on the motor, www.powroll.com and then use a newer CRF230 cylinder head. Coeshow says they are a huge step up in performance from the 200x heads.

[Levithan]

You'll probably want a +4 rear axle, some type of custom rear suspension linkage to get it lower in the back (or a shorter shock) mod the front forks to get shorter in the front.

How would I mod the front forks to make them shorter? Also, where would I have to go to get the custom suspension linkage? Is there any way I could fab up something myself? I do have an Acetaline Torch at my house, and my dad is an experienced welder, so those are a couple plusses. Anything else I should look into? Thanks! :beer

[Billy Golightly]

The front is pretty easy. I haven't been into the forks on a 200x but on my Rs here is what you do. The 1985 models had 2 springs. One real long one, and a shorter one about 3.5 inches at the top. You pull the forks apart and dissasemble them, remove the small top spring and place it under the dampening rod in the fork (It'll help to look at a shcematic to understand this). What this does is so that the machine now sites 3.5 inches lower and when the front end gets light, instead of having the previous 3.5 inches of just free travel with no restriction since you removed the spring out of the top (Would make wheelies easier, bad thing on the track) the weight of the front tire now has to pull and compress that shorter spring before it can lift up.

On the rear, you might be able to make a linkage where the shock mounts further back or down on the swingarm to allow it to go lower. Or you might have to make a whole new swingarm with adjustable mounting points. That'd be bad ass heh.