Suspension Questions...

[Xian_13]

Okay instead of bugging everyone at the track...
I will bug everyone on the Board! ;D

The Bike, '99 ZX6R (Fox Rear shock)

The questions....

How close should my zip-tie make it to the triple tree while under racing conditions?
Presently there is 1.150 inches left till the zip tie meets the bottom fork clamp. (noted for the races at MAM)

How Much rider Sag should the there be. Rider with gear on is 150# (if he had a big lunch ;D )
Free sag on the bike is about 1.000 inches on the forks, and .250 inches measured from the rear axle to the Sub frame.

If the bike is jacked up another .250 inches in the rear of the bike, How much will this affect the geometry of the bike while corning?

Thanks in advance for any input!
Xian

[tzracer]

The distance to the zip tie is irrelavent. You need to know the full travel of the fork. When a fork bottoms with the forks in the stock position, there is almost always space between the fork slider and the bottom of the lower t-clamp. This distance will change depending upon where the forks are in thr triple clamps (have they been moved up or down). You will need to find out the front fork travel. I used to pull a fork cap and push up on the fork, with zip tie in place, let fork drop to full extesion, measure from top of fork to zip tie, this is full travel. At the track, put bike on front stand that lifts by steering stem so front wheel is at full extension, measure to zip tie, this is travel used on track. Compare to full travel to see how much used. I don't like to use full travel.

Sag - I like to start with about 1" to 1.25" front, 0.75" to 1" rear sag with rider on board.

Ride height (front and rear) is up to rider preference.

[bmfgsxr]

oh boy are you looking for a lot of info my man.

to start with, you should be using most of your fork travel. sounds like your forks are a bit too stiff. set your sags first. front free sag should be about 15mm and rider sag should be  about 35mm

rear should be about 10mm of free sag, and 25-30 rider sag. if you cant get these numbers than your spring rates are off.  you should only adjust the rear ride height if your getting too much squat on corner exits causing you to run wide( basic reason for raising the rear).  if your getting too much wheel spin on exits then lower the rear of the bike( this is all considering your spring rate is correct, and riding position is how it basically should be). for the front of the bike only adjust ride height if your having trouble entering the turn. if its too much work to get it to turn in then pull the forks up through the triples a bit. dont do more than 5mm at a clip though. if it falls into a turn and doesnt hold a line nice, and feels a bit vague up front then drop the forks through the triples(raise the front of the bike) there are an enormous amount of variables to take into account but these are a couple of basic rules you can follow to get you on the right road.

[Xian_13]

The Ride height issue I have is I am scraping... Pegs, lower, R-brake and tail pipe. I know I can change the height by upto .250 in the rear, and maybe .125 up front.

As fars as asking for alot of info, I am an Info junky  :P

And right now, all I have are a million of questions with little resource to answer, about suspension.

[MELK-MAN]

The Ride height issue I have is I am scraping... Pegs, lower, R-brake and tail pipe. I know I can change the height by upto .250 in the rear, and maybe .125 up front.

As fars as asking for alot of info, I am an Info junky  :P

And right now, all I have are a million of questions with little resource to answer, about suspension.

scraping stuff is BAD.. just askin to kiss the pavement. try gettin off the bike more perhaps in turns to reduce lean angle while still going through as fast or faster. Often at track days i will see fellas sitting bolt upright on the bike but leaning the piss out of the bike. Im not familiar with the bike your speaking of to say much more :)

[ecumike]

@ VIR I was scraping bodywork with my stock shock:



(photo by Keith @ www.motographic.com)

We quick fixed this by raising the forks 30mm through the triple clamp. The bike 1. Didn't scrape anyomore 2. Rode a hell of alot better. (I had other suspension issues besides ride height)

About 2 weeks ago I fitted a new penske and got the forks revalved... it's like a whole new bike now  ;D

And yes, from what I've read and heard, the #s you hear or read about sag are just a baseline/guideline. You results may vary according to your style, don't be afraid to increase or descrease settings. Just remember to write down what you did, so it you don't like it, you can put it back to what it was.