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Flattrack for Dummies
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Posted by: Tom68
Has anybody found flattrack for dummies lately? How do you find it?
Posted by: Rich Rohrich
The "Flattrack for Dummies" document used to be posted in the Tuners Forum at flattrack.com
If you can't find the file let me know and I'll be happy to e-mail you a copy.
In the meantime ....
A while back Tryce Welch (Fast Forward Racing) was kind enough to share this info on DTX weight bias and setup info with a group of folks on the Dirt Track forums. I hope he doesn't mind me sharing it here. It gave me some some things to think about and helped me get a starting point to work from, hopefully it will do the same for you. :thumbsup:
A big 
to Tryce for sharing the info in the first place.
Ok, right out of the Top Secret FFR files(lol).
C&J 505 Rotax...no fuel
Crank to Rear Axle(centered)28.5'
Crank to Front Axle(55mm offset)26.25'
Front Wheel wt...120#
Rear Wheel wt...120#
Weight Bias...50%x50%%
Rake....25 degrees
notes...fuel changes bias to 50.5x49.5 fr to rr
KX250DTX...1/2 tank fuel
Crank to Rear Axle...31'
Crank to Front Axle(stock 55mm offset)...25'
Front Wheel Weight...115#
Rear Wheel Weight...105#
Weight Bias...51.5%x49.5%
Rake...25.5 degrees
If you notice, the front and rear axle to crank are within an inch and the bias is within 1%.
These measurements are from my notes and what other builders have done I cannot say.
As far as the trail figure goes, The only time I had a problem that might be attributed to the difference in the 2 styles of bikes, was a few yrs ago when I first started setting up DTXers, several local pros notice the front end pushed going into the turns on a 1/2 mile. Stan Millard helped me out by suggesting and building me a set of 65mm offset clamps for a YZ250. Thats all it took to get rid of the push. Now after several yrs and many bikes later, wether its the new setups or just the riders adjusting their riding style or whatever, I never found it nessecary to go to the adjustable clamps. Seeing that most of the younger riders grow up on the DTX bikes, I tend to think that they have just learned to ride it 'DTX' style. I could see where the riders that have been on framers for a long time, might feel 'awkward' at first, but then everyone needed to adjust to the single shocks when they first came out. I am not or never have, claimed the DTX is the ultimate DTer, but they can be a very versatile alternative.
Posted by: Tom68
Thanks, thought I might need internet for dummies first.
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