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Old 01-23-2008, 06:52 AM   #58
NC Rick
Cogent Dynamics Inc
 
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Joined: Aug 2007
Location: Asheville, NC
Oddometer: 566
Neepuk, you lucky... That sounds so cool! I wana come and ride!

Frank, I am overly simple sometimes no doubt that the primary function of the damper is to provide critical damping to the spring and the controlled mass to prevent over or under shoot of the reaction. The damping does more providing feel and "helping the spring" Sometimes the damper and spring are controlling the wheel movement over the ground and other times they are controlling the bike and rider with the wheels staying closer to stationary (with respect to the dampers). Not at all simple and I really think the art of getting a good setup transcends the pure theory (this is a nice way to say that I don't understand it all ) On the DR, the shock may be providing something like 600 lbs of force at the rear wheel when it is being compressed by 5 inches / second.

BigMaggot, the oil viscosity has a limited effect on the damper forces because the shim deflection should be the primary control. It will effect bleed and cause a firming of the low speed performance of the shock. The heavy oil has other undesirable effects including more temperature caused viscosity change and potentially causing a big spike in damping force at high damper speeds. The compression damping adjuster on the DR is a controlled "blow-off" and effects the shock primarily on "hits". You can do what you want by just modifying thee rebound shim stack and that is a perfectly viable thing to do. That is something you can do if you have a few tools and a source of dry nitrogen to refill the shock. People who send shocks to us for that would typically pay about $100 or so to have that done. Very importantly, doing that kind of work would include the critical service of the shock. I recomend that everyone service their shock at about 12 to 15K miles or even much sooner if the bike gets used real hard.

DRinda, the dogbone change will change both wheel travel and lever ratio, with our shock modification, you could just use the ride height adjuster to dial in the additional height. What I would want to do is to look at the additional travel in the front and think about extending the shock in a way that give a little more travel. Lets say we add 1" of hight to the rear, we could then add 1" of wheel travel. Another possible way to address the same issue would be to add an internal spacer to the new fork to correct the ride height and travel at the front. I am 6'1" and have problems with my toe finding mother earth on some of the sidehill conditions in the woods. More hight isn't always what we want. For jumps, it would be great! I have an extra set of DRZ forks here and was thinking about a swap like that one day. I know from owning a DRZ that I would want to do a revalve of the fork at the same time.
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