05-16-2005, 03:00 PM
I need to get my geometry right on my racebike. When I bought it, it had used up Dragon SCs on it and is set up for that tire. I'm now using different tires (BT002s, DCs, etc.). What I want to know is where to measure to and from and what the right baseline ride heights are with a Penske shock.
Basically I want to know a dimension, like from the subframe to the ground so I can get the right ride height. I believe the front is pretty close but I don't know where to start there either because all the tires have different circumferences. Any knowlegable racers who can help me or point me to a website that can? Thanks.
05-16-2005, 03:20 PM
By the way, it's a 2000, not sure if there is a difference.
05-25-2005, 11:50 AM
The best suggestion is to check with the track side vendor for the brand of tires you are running. they can usually point you towards a racer that will have a bike that is set up that you can get some baseline numbers from.
personally, when i set up a bike, i measure from the bottom of the lower triple clamp to the top of the front axle to set my baseline. then i use a caliper to determine and set the amount of fork tubes that extend above the top triple. when installing a new shock, i measure from eyelet to eyelet and set length before installing. from there, i measure from the top of the rear axle straight up to a fixed point on the tail of the bike and adjust from there. once i have a setup that works, i adjust ride height for the changes in radius of the tires. also, i try to maintain some consistency and i dont change tires unless i have time to actually test them and dial the bike in for them. i keep a detailed notebook with my measurements and associated laptimes and comments so that i can reference them when making changes.
overall, you are looking for a setup that provides stability at speed while still maintaining manuverability. you get one at the expense of the other and you have to decide where your happy medium is.