Front tires cupping

[wileebuc]

what can be some of the causes of the stock front tires cupping, approx 8500 miles. cupping on both sides. front suspension is also set at stock setting

[woobie]

I was gonna say it's the crapadams, but since you have a 750 you have dunlops?

Maybe your tire pressue is off?

[md86]

Check the "rolling stock" section for tire opinions , there should be TONS of them there .
8500 miles is a good bit for ANY tire , IMO . I usually get around half that , and I RELIGIOUSLY check my pressures . I run them on the low side , but still within spec as per the manufacturer .

[The CyberPoet]

Tire cupping is caused by running under-inflated for the load they're carrying. As the tire comes around the amount of distortion causes the contact patch to flatten excessively, dragging the edge of the next tread block unevenly compared to the trailing edge of the last tread block. It means you need to up the pressures (unless you happen to weigh in at 140lbs, ignore the stock 33/36 psi recommendations on the bike).

If the tires are still the original tires (see the imprinted manufacture date on the sidewall), the tires need to be replaced anyway strictly due to age -- five year max on that.

Suggest you read http://www.katriders.com/forums/viewtopic.php?t=7909 for opinions on various tires and important handling/sizing/etc. info.

Cheers
=-= The CyberPoet

[ThAzKat]

Most of that stuff you post Cyber should be put in it's own forum so people can go to it and find the info easily. Simply put, A How to forum, starting with Tires, oil and Centerstand LOL

[pvt. bloggins]

And that is why you should check your air pressure before very ride....

[WildKat]

If you want super sticky, quick warm, good quality all around tires, go for the Pilot powers, you won't be dissapointed! Ive definately been converted!

[The CyberPoet]

OK,,, if my weight dictates tire prseeure,,,why does the sticker basically have the same pressure for single or dual riders?

hahahah!

The reality is that the factory (Suzuki in this case) isn't worried about how fast you burn through tires; they want to make sure that you have good grip. Lower tire pressures put a bigger sweet spot on the ground, but you pay the penalty in tire wear and in wet weather conditions (where the bigger sweet spot increases the chance of hydroplaning).

The sticker is by a Japanese firm. Typical Japanese rider is 140lbs with gear, soaking wet, right? That's just a joke... more seriously, odds are the stickers were the responsibility of someone in the graphics design department and had zero engineering input.

Cheers
=-= The CyberPoet

[Anonymous]

Does someone have some GOOD pictures of cupped tires? I know it's been asked like 100 times, but i don't care

[Selby]

Here's a good description of what is happening to cause cupping from http://www.rattlebars.com/valkfaq/tirewear/:

CUPPING:
Cupping, which is more accurately described as scalloping, is a natural wear pattern on motorcycle tires and it will always follow the tread pattern. It is not a sign that you have bad suspension parts. It merely shows that your tire is indeed gripping the road when you make turns (thank you for that Mr. Tire!). This scalloping develops within the side wear bands of a leaned motorcycle. The extreme forces that come in to play when the bike is leaned in a turn are what produce the effect and when the wear becomes sufficient, one will experience vibration and noise when one banks into a turn. Upon examination of the pictures at left of our sample rear Avon, our dusted front VTX Dunlop D256, and the picture of our chalked Dunlop D206 one can see how the scalloping follows the tread pattern. The leading edge of the tread grips the road and the rubber is scuffed off the tire in that area causing a depression. As the tire rotates, the pressure moves to the trailing edge of the tread pattern and the tire flexes there which causes less scuffing so less material is ground off the tire. The more complex the tread pattern, the more complex the scalloping pattern will be. The softer the compound of the tire, the sooner this scalloping will develop. Radial tires are more prone to cupping than are bias ply because the compound of radials is softer. As one can see, the simple tread pattern of the Avon pictured produces a simpler scallop pattern while the more complex VTX D256 Dunlop is somewhat involved, though still easily seen in our photo. Scalloping on the Valkyrie Dunlop D206 is very hard to photograph because of the complex tread pattern. Low tire pressure will exacerbate this wear pattern and you will lose many serviceable miles by running low. Improper balance has nothing to do with "cupping" on a motorcycle tire. Improper balance will merely cause your bike to vibrate within certain specific speed ranges.

The site (above) also has a credible theory on why the left side of a tire wears out before the right (at least, in countries where we drive on the right side of the road).

[The CyberPoet]

Will severe scalloping or cupping cause the whole front fork to, not just vibrate, but really whobble the instant you let go of both gripps? I ask because my '98 came with the front very cupped (orig. tires I assume) I'm changing them out on Monday, but I'm wondering if I can expect the whobble to disappear, or if it may be something else.
Oppinions??

It can be (and often is) front the tire scallop, in which case it should be gone. If it's from another source, it may be minimized but still there.

Cheers,
=-= The CyberPoet