Rick Ramsey fetched himself a new Yamaha WR250R from the Gunnison, Colorado, dealer today. His Yamaha WR section is relatively new, but knowing his passion for tinkering, you can bet it'll be full of useful info in no time flat!
Rick's site: HERE
Saturday, August 8, 2009
Wednesday, August 5, 2009
Question about Yamaha WR lowering on Supermotojunkie.com as related to raising the forks on the WR250X.
"10mm is the most popular starting point to raise the forks in the triple clamps; the most you can move the forks SAFELY on this bike is 18mm. There is no 1:1 ratio of fork/rear end lowering because changes to rake/trail (the fork) affect geometry at a different rate than changes to the rear.
Extensive testing showed us that 2 inches (just a hair under, really) is the most you can lower the rear of the R and X while still maintaining a "balanced" ride up front. Anything more than 2 inches total in rear and the forks cannot safely be raised to give a ride capable of withstanding race-type speeds and handling. This is not to say a very very short leisurely rider could not get away with more lowering.
Depending on rider preference you just slide the forks up or down a few millimeters. As you may or may not know, 6mm is approximately 1/4 inch. But 10mm is a great starting point. Too much and the bike headshakes and oversteers. Not enough and it turns like a NHRA dragster and understeers. Thankfully it takes just a few bolts to make the fork height changes; please retorque the clamp bolts correctly.
As someone else noted, 1/3 of total travel is used for sag, give or take a few millimeter. The "give or take" is, again, based on personal preference.
And as the installation instructions note, make sure your chain is properly tightened (approximately 45-50mm of slack measured at the middle/bottom of the chain when the bike is off the stand....someone please correct me if I'm a bit off on this comment)."