hey guys what dose a cupped rear tire mean? Its cupped on the left outer edge.

 

On a car it normally means worn out shocks--or tow-in tow-out is bad. Not sure on a bike but I would check for proper front and rear wheel alingment. You also may want to stiffen your shocks up a bit.

 

Hope this explains the term i picked it up on another forum.
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. This scalloping takes place 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 on a scalloped tire. 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 become evident. Radial tires are more prone to cupping than are bias ply because the compound of radials is more often softer. Improper balance has nothing to do with "cupping" on a motorcycle tire. Improper balance will merely cause your bike to vibrate at speed. Low tire pressure will exacerbate this wear pattern and you will lose many servicable miles by running low. Check pressure often.

 

WOW thanks that was a relay good answer.
Thank you

 

Yep--That makes good sense. You must do a lot of left turns (being cupped on left side only). heeheeThanks cornishman!