Ok, so my front tires start to get cupped at about 1500 miles and I can't figure out why. There is no cupping on the rear. I'm thinking, but not sure that my weight is doing it. I'm 6-2 and weight about 240ish...I'm a fatty. I'm thinking it's from cornering. Do I need to install heavier springs in the forks? I've got the oem springs almost all the way for stiffness as it is. It handles great and it doesn't pogo when stopping or anything, just shortens my front tire life.

 

I should mention that it has done this equally with 207's, 208's and now my newish qualifiers are starting to do it.

 

I don't know but there's a bump for ya.

 

What tire preasure do you run?

 

you're almost 100 lbs over what the stock spring rate can handle. but before doing all this, check to make sure that your suspension is evenly adjusted on each side.

 

I run 38-40 psi rear
and 33-34 psi front

The suspension settings are equal on both sides too - L/R. I also try to keep weight distribution 40/60 front/rear when cornering hard and what not and the cupping is equal on the left and right side of the front tire. Like I said, handling is good and the front doesn't dive in corners. Should I look into the heavier springs and what should I go with? And why doesn't the rear get cupped? Thanks

 

rear tire doesn't get cupped as when you're leaning, it doesn't move, but the front tire is leaned and turned opposite way of turning direction.

i would recommend ohlins springs for the front as their spring rates are pretty on for the rated weight...if you go racetech, you should go up.

 

You mean if I go with the ohlins to get the exact weight or close but if I go racetech that I should go heavier? Are they not as strong?

 

it's not about strength of the spring but more about the spring rate rating.
racetech's rating is just a bit 'off'. just be aware if you do go racetech.

also, if you do repring, technically you should revalve too. check around, a decent spring and vavle should cost like 4 bills...includes new springs, fork oil, labor, revalving (using existing parts), etc...this will be good enough for some track and twists...

for all track and twists, the cost goes up...comes to like 600-700 bucks to well over 1K...to even higher.

only place that i would recommend is one local to me...and that's www.ppsracing.com not beacause it's the best but because they are great and they are local. guys further south and north than i am use other local places.

as for the rear...i would try and find an ohlins replacement or see if a suspension shop can resrping it and revalve it to your weight, or revalve as close as possible to your weight.

total bling for front and rear to get it good enough should be like 6-7 bills.

 

Maybe these questions should be posted elsewhere, but it bears on this discussion.
1) What exactly is cupping?
2) I'm 205 and have stock suspension. I've been on track once (plan to do it again soon) and don't "think" I need aftermarket suspension. Why would a person like me want to spend 4-700 bucks on m/c parts when I don't race? I don't have any handling problems at this point, my speed/ skill is not to the point to manifest deficiencies in the equipment.