So I am wanting to experiment with rear ride height. Do I raise 5mm at a time or is that too big or small a change to play with? Goal is better turning on RC51 SP1, will be running Penske 8983 when it gets installed. While we are on the subject- where did you guys who do/did race these end up setting your forks in the triples. I have heard that making the bike taller overall improved cornering. My tuner has a 51 with a full Ohlins setup so I can't compare my forks to his because his are longer overall. Help would be appreciated...
5mm is a pretty decent chunk to be moving for rear ride height, but it'll make very clear to you the changes. If it feels really twitchy and unstable, go backwards until it feels good.
When you say 5mm, are you talking at the shock or ride height measured at the axle up to the subframe? In that's way too much at the shock, and not that much at the axle.
T-man recommended to me to make big changes so that they can be felt. You'll immediately know if you are going in the right or wrong direction. You might also want to ping Dan Kyle since he's got a ridiculous amount of information on the Are-see and see if you can get pointed in the right direction. Also what is going on internally in the forks? Are they stock or have they been modified? The Showas on the bike have very long and soft top out springs, so trying to properly set sag can be a bit of a challenge with those.
5mm change would be measured ride height from axle to subframe for the change. The shock itself has 12mm of adjustment. The shock as shipped measures about 6mm longer than the stocker, so I gather I'm looking at at least a 12mm rise just starting out. I'm thinking I need to raise the front about another line (5mm) which would put me taller overall but with the 6 or so rise in the rear included. Looks like any change will have to be made at the triples. Forks were sprung with Racetech springs to get rid of the negative preload and since it is an 01 it has the longer forks. They were modified as recommended by DK and Hord Power. Went with Racetechs recommended .95 rate and baseline rebound/comp/ sag settings. Still hoping someone who weighs about 180 with gear will chime in with a setting that worked well for them. As shipped from the factory measured rake and trail was 23.5/95mm. No stability problems stock, just needex to upgrade the factory shock to help me finish turns. Didn't want to do the rear without fixing what needed to be done in the front and I did it all at once since I needed fork seals anyway. Added Gold valves too and specified track use for the recommended valving.
Made a test run on the street today and came back with chicken strips on the rear tire where there normally are none and smaller than normal strips on the front tire. Also found that my tire pressures were set to stock factory settings (45 in the rear) where I normally run about 30. Could a raise in rear ride height cause this, or could the higher pressures cause this?
If I remember correctly we we ended up adding 5mm at the the shock on mine. The front end was whatever the guys at Traxxion do when they revalve and respring the stock forks and set at first line on the fork tubes above the triples. I don't remember the specific spring rates but they differ if we aren't the same weight anyway.
Thanks Venom. That's what I was looking for. Going to put my forks back to one line showing tonight. Clickers seem to work well with racetechs recommended settings. A real improvement to the bike overall. Hoping for good weather on Sunday...
Do you mean increased height because of more pressure? I never considered that. Either way, will the increase cause the different wear pattern like I described? Or do you mean lean angle? Wow this is confusing. Bottom line- I rode a path that I ride frequently and came back with a different result than what I had before the changes. Going to the track tomorrow, so I should hopefully be able to compare result of change from session to session. Just don't want to start out totally wrong in the beginning.
