XR 100 Must haves

Well what are they? Looks like I am picking up an all stock 98 next week, I would like to do more of a DT/Ice racer than a RR build. TIA

 

BBR spring or shock, clean the carb. Ride.

On the dirt, makes a great training tool. Although I have a feeling if you start doing ice riding with it, you'll immediately want something bigger/faster.

 

And bring it to the GNF and leave it stock and IT's ON!!!!!!!!!

 

I have only road raced mine, but the Moose Racing bark busters have saved me from a lot of lever purchases.

Buy a folding shift lever as well. my stocker was easy enough to bend back for the first 3 or 4 crashes, but I was having to pit-in to grab pliers to do it. the folding lever has performed flawlessly over the last year or so, and I've only been crashing it at higher speeds...

OEM brake cable seems to be better (IMHO) than the motion pro. Better meaning "slightly less awful."

 

Geez don't make me whip on you again lol

 

A 16" front rim? I have one ill sell if you need one, rim only still in original packaging.

 

Dirt track racing? Check the local clubs mad dog rules and follow them.. I run the stock wheels for DT with a shinko 705 front and a kendra k761 (I think) on the rear.
I have to no idea about ice racing lol

 

OEM brake cable is head and shoulders better then that motion pro shit!
Also on shoes seem better then any of the ebc ones iv tried. Don't run the ebc sintered ones they fad in about two laps on a kart track.

 

Oh also something I've recently discovered. Run the exhaust valve at .003-.004 if you're going to be at sustained rpm a lot or if you road race it. If you miss a shift(which is easy with the small shifter) you'll be better off with it a little loosend then spec. IMO.
Also if you need a bigger shifter xr400 shifters fit right on.

 

so you run OEM shoes?

 

Right now I run ebc dual carbons. But I'm going to try the stock shoes at my next track day they are supposed to be more consistent With less fade. I would trade the better braking power of the ebcs for that right now.

 

yeah, find out what rules need to be followed first but for an outlaw there is tons of stuff you can do.

heres the thing though.. alot of the mods will be counter productive if your main goal is training. in that case keep it stock as possible so you can learn how to ride around its shortcomings which also teaches how to ride a slow bike fast and is invaluable lessons IMO.


some mods I like: double up the lower fork clamp with one from another, weld up the bottom dampening holes in the forks. if you go with a 16" front one from an '83-'85 xl80s with axle and backing plate allows better braking.

xr80 chain and sprockets (420 instead of 428) lightens it up. xr80 clutch pack has one less disc and plate so less mass to rotate and makes it rev quicker.

xr80 stock cam has slightly more lift but less duration and could be useful depending on the situation/track. xr80 cylinder head has smaller combustion chamber but also smaller cooling fins.

I actually run XR80 rims, swingarm, forks, and alot more on my 100s mostly for lightness but I feel it handles better too.

Bridgestone Trail-Wings available for the XL80s and xl100s are absolutely amazing tires nomatter what the posers call them. found to have more grip on polished concrete than any slicks period for indoor tracks and they will lay down a blue groove all by themselves in short order on a fresh backyard flattrack. I run these exclusively now after experimenting quite a bit with others but if you are running only on asphalt they will be a limiter.

 

I run BT45s front and rear on stock wheels (Class doesn't let us go to the 16s), cut the top 4 inches of both fork springs (the progressive part) and make spacers to fill the gap (my spacers are 4.25 inches for a little pre-load), run the thickest fork oil you can find (I am actually using ATF right now), and drop the fork as far as you can in the triples. I did all that and I have zero front end chatter. I can second the XR80 sprockets and chain. I also used a downhill mountain bike handlebar. It is .25 inch thick and has crashed really well, and it is about an inch lower rise then the stock bars. This helped get down low over the front and keep weight on the front wheel.

 

http://miniroadracers.informe.com/forum/tech-questions-f2/xr-crf-100-setup-guide-t2745.html

Pretty good set up guide for road race spec class. Might be somewhat helpful.

 

You mean press out the stem on the lower triple and slap it on there as another brace?

 

exactly.

 

Going to be bumping this thread a bit looking for info, decided not to be a twat and kart track this little thing down here as well.

I have a set of XR80 forks sitting in a box in the garage. All things the same, would it benefit the bike geometry wise to throw them on vs the 100 forks?

They are the same except shorter I believe? If I have uprated springs in my 100 forks and swap them into the 80 forks its going to add the fork length difference in preload correct?

 

Looks like about 23mm longer for the post '00 XR100 springs vs the XR80 springs

 

Can someone give me a heads up on the number of links needed for the 428 to 420 chain conversion on the XR/CRF100?

* never mind its the same as stock right, the links are the same pitch on 420/428 just a wider link *

 

will any one be running these at the GNF?