mini racing a grom!

Groms are legal in the "Formula 3" class for the Eastern Mini Roadracing Championship at PIRC (BeaveRun) June 21 and 22.

I'd love to see some Groms out there with the stock XR/CRF guys and a handful of NSF's and the like.

If there are 3 or more Groms that show up, they will get their own class.

 

looking to buy an xr/crf 100 to do some mini trackdays/racing.. are there any good links on threads for basic bike setups, equipment, tires, and such?

there are quite a few on craigslist, but most appear to be pretty much stock with dirt bike tires. just trying to get a feel on what would need to be modified/converted for the track.

 

www.supermotojunkie.com with a search for "XR100" will get you a lot of good info.

www.ohiominigp.com (forum link) has sticky posts for XR100 setup as well.

I'll PM you with off-the-top-of-my-head setup.

 

good stuff!

 

Herrin's track has a pretty massive turnout for the stock xr class. Only mods allowed are jetting, springs for forks/shock, front wheel converted to stock 16" xr80 wheel and tires. Be a good place to start if your in that area.

 

BT45s stick amazingly well I've just learned with my TTR 125. BT45 on the stock 16" rear, a take off Bridgestone 125GP front slick on a YZ80 17" front wheel and the front pushed before the rear. What the other racers are telling me is the tradeoff between a slick vs BT45 is lifespan, the BT45s wear really fast. I ran on bone stock suspension and had a ball. I'm going to get the OEM shock resprung / refreshed and mount a similarly tuned up YZ80 front end just because I'm jumping trying SuperMoto, but I wouldn't go crazy if I was running strictly pavement.

 

yeah, that's the plan! i think i'm about 2-3 hours from his track.

 

define "really fast" when you talk about wear on the BT's.

Maybe my local track's surface is just slicker than yours, but I haven't experienced much wear.

Running a brand new set of BT's, I did notice that (just like the big bikes) the rear wears faster than the front. So I'll swap them at the end of the year and get 2 years out of this set...

I may also get more life out of mine because we run the same track CW and CCW on alternating rounds. Very even wear, with only 2 rounds at other tracks.

 

there is a nice xr on the cammra facebook page for 1,000 looks really clean

 

:up:

sent him a message! thanks for the heads up!

 

First race of the season we closed things out with a 1 hour endurance GP race, no dirt section. I have a brandy new BT45 rear and people were warning me that said endurance would kill it, while debating weather or not to finish their's off that evening. Post racing, that BT45 feels as soft as a rain tire... sticks like glue though!

 

Up here we run the stock bikes. Only changes are tires (BT45 is what most run), springs, and fork oil. We even have to run the stock front wheel. One of the problems with the fork is chatter. I found a way to fix it cheap. Cut the top 4 inches off the springs (the progressive tight coils) and make spacers to take up the room. Then I put in the heaviest fork oil you can find (I used 20wt.) and raise the oil 10mm from the stock setting. I also made my spacers 1/2 inch longer then what I cut off the springs for a bit of pre-load. No more chatter and the front sticks like glue.

Edit. I have run 2 seasons and 2 endurance races (my daughter uses the same bike in 3 classes and I run 2 classes each race) on 1 set of tires and they still have at least a season left on them.

 

The BTs last a pretty long time on the Hondas. Maybe the TTRs put more wear on them?? My current set has an easy 300 laps on them and they still look new.

 

I did 60 laps last Saturday, which is about what a 1-hour endurance would be. Track surface must play a major factor, because I think most people are getting 2 seasons out of theirs.

 

great info.

 

What are you running for pressures?

 

how did you get the surface of the cut spring flat enough to have everything sit without binding?

 

Just used a grinder.

 

10-4, guess close enough is really close enough lol

 

I ran 18psi the first weekend, and 16 this past weekend. JH2 recommended 15psi, but I can't bring myself to go that low. 16 may be the basement for me.

Saturday will only be my third time riding on BT45's. I ran Pirelli ML75 moped tires last season. For a kid or anorexic adult, those are a great option. I experienced a lot of side-wall buckling though, and I'm only 170 lbs. (probably more like 200 with gear). Cheap as dirt.