kinell Posted January 11, 2007 Report Share Posted January 11, 2007 Altering the forks by sliding them up or down the yokes does what exactly? Quote Link to comment Share on other sites More sharing options...
jezza Posted January 11, 2007 Report Share Posted January 11, 2007 Alters the angle of the forks slightly. Forks level with top clamp, bike will turn more easily. Yokes slid down so that the fork leg protrudes above it, bike will be more stable. Quote Link to comment Share on other sites More sharing options...
scorpa3 Posted January 11, 2007 Report Share Posted January 11, 2007 Alters the angle of the forks slightly.Forks level with top clamp, bike will turn more easily. Yokes slid down so that the fork leg protrudes above it, bike will be more stable. Isn't that the other way around? In the old road racing days, when we needed to make a bike more stable at high speed, for example at the Isle of Man TT, we used to increase the front ride height and make sure there was a little sag on the rear preload, thus increasing the trail and making the bike more stable. At low speed circuits where fast turn in was required, such as Mallory Park or Cadwell, we would drop the front ride height and remove all the rear sag completely. I know no better, but isn't that true for a trials bike too? Quote Link to comment Share on other sites More sharing options...
jezza Posted January 11, 2007 Report Share Posted January 11, 2007 Must admit I thought about it for a while and then looked in a handbook for a Honda MX bike. It says there re fork height adjustment; On long fast tracks where there are few turns, consider a position with the top surface of the upper clamp positioned below the top of the fork tube, the standard position aligns the top of the fork tube with the top of the upper triple clamp. If you are right Scorpa3, no wonder that bike kept spitting me off. Probably getting their own back for Iwa Jima In a paragraph re rear suspension it says; Reducing the spring preload will increase fork rake and trail so stability in a straight line is improved. Seems to be contradictory Conclusion, reading is bad for you! Thinking is worse. Please direct any abuse to the Honda Motor Co. Quote Link to comment Share on other sites More sharing options...
scorpa3 Posted January 11, 2007 Report Share Posted January 11, 2007 Must admit I thought about it for a while and then looked in a handbook for a Honda MX bike. It says there re fork height adjustment;On long fast tracks where there are few turns, consider a position with the top surface of the upper clamp positioned below the top of the fork tube, the standard position aligns the top of the fork tube with the top of the upper triple clamp. In a paragraph re rear suspension it says; Reducing the spring preload will increase fork rake and trail so stability in a straight line is improved. This is another way of putting over what I was trying to describe. I said we used to make sure there was a little sag on the rear preload at circuits such as the TT,(Which are fast bumpy tracks) This is done by winding off the preload on the rear sping. It makes the bike feel 'longer' and more stable. But the down side of this is it requires more effort to turn, which on a short tight track is not so desirable. Quote Link to comment Share on other sites More sharing options...
jezza Posted January 11, 2007 Report Share Posted January 11, 2007 (edited) Yep, that sounds spot on. Perhaps the Honda manual lost something in translation. It also said change the piston every 5 mins and I never paid any attention to that..... too busy fiddling with the fork height. Edited January 11, 2007 by Kinell Quote Link to comment Share on other sites More sharing options...
woody Posted January 11, 2007 Report Share Posted January 11, 2007 Imagine, if you slide the yokes all the way down the stanchions as far as they will go, the front of the bike will drop and the front wheel will be pulled in towards the frame. The angle of the forks in relation to vertical will be reduced making the steering respond quicker. This also has the effect of making the bike a little more unstable in a straight line as the steering will deflect more easily of rocks or bumps etc. If the yokes are slid all the way up to the top of the stanchions the steering angle is increased as it raises the front of the bike, pushing the front wheel away from the frame, therefore the steering responds slower - imagine a chopper. This means the bike is more stable in a straight line as when the front wheel hits rocks or bumps it responds slower and doesn't deflect so easily. Look at an old Bulto and Ossa for a comparison, the Bulto has the front wheel pushed out and has good straight line stability up rocky streams, but steers a bit slow for tight nadgery stuff. The Ossa has the wheel pulled back more with a steeper steering angle and is quicker steering in nadgery setions (but obviously is still bloody brilliant up rocky streams due to a superb chassis - an unashamedly unbiased view) Reducing rear spring preload has the same effect of sliding the yoke to the top of the stanchions, it drops the rear of the bike, raising the front making the bike more stable in a straight line and slowing down the steering - more applicable to racing disciplines rather than trials though. Go too far at the back though and the bike will just float at the front which will be too light and stable won't be the expression you're looking for.... Quote Link to comment Share on other sites More sharing options...
kinell Posted January 11, 2007 Author Report Share Posted January 11, 2007 Brilliant explanation Woody (them two buggers up there just confused me ) I asked the question because I saw a bike at JLI's that had the forks flush with the top yoke - just made me curious I suppose... Cheers Quote Link to comment Share on other sites More sharing options...
phb Posted January 12, 2007 Report Share Posted January 12, 2007 the way you ride KINNELL you might as well take the forks out as it might improve your riding Quote Link to comment Share on other sites More sharing options...
kinell Posted January 12, 2007 Author Report Share Posted January 12, 2007 I just cant' take it any more, goodbye cruel world! Quote Link to comment Share on other sites More sharing options...
boofont Posted January 13, 2007 Report Share Posted January 13, 2007 Once again Woody tells it like it it is. If I may add? Lower the forks and the bike will wash out less, raise them and it will wash out more. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.