I hope somebody can help me out with this, I have a 09 ultra classic. I have had issues with tire cupping since I bought the bike with 13k on the clock. I am **** about tire pressure. Always check before I ride. I only have about 6K on the tire in the pic. the left side of the tire is wearing way faster than the right. Almost no tread left on the left side of tire. Right side is cupped and the front tire is cupping as well. Any ideas on what might be causing all the excessive wear and cupping and why it seems to be concentrated on the left side of the rear tire?

 

Perhaps its those smokey broadslides you like doing, round l/h bends?! Joking aside no idea, but it will be interesting to see what comes up. Lop-sided wear like that is certainly odd.

 

rear wheel alignment is possibly off

 

I am wondering if the bike was involved in an accident before you purchased it. Tire alignment may be off because of a bent frame or swing arm.

 

http://www.rattlebars.com/tirewear/index.html
[from article]
Left hand turns have a larger radius than right hand turns in right side driving countries, hence you ride farther (and likely faster) turning left than turning right with subsequent increased side band wear on the tire's left side. The left side of your tire has more miles on it (in some extreme cases, twice as many) than the right side of your tire. And the side of your tire only gets mileage when you are leaned in a turn, otherwise, this area of your tire does not contact the pavement at all as shown in the photo. European left side drivers find that the right side of their front tires will wear out first. Quite the opposite effect for precisely the same reasons reversed.

 

Dan, so I wasn't so far off after all!

 

I've also read that the crown of many roads (for drainage) puts more wear on the left side of a tire, (at least here in the states) where we (mostly) ride on the right side of the road. This would be more pronounced if you mainly ride longer, straighter roads.

 

I agree. I don't think the wear on this tire is from longer left hand turns or crowned roads or we would all be seeing this kind of wear. Might see it at 12 to 15K but not at 6K. Something is definitely wrong with the way this tire is tracking. Maybe the swing arm is bent and the tire is riding at an angle (right side higher than left side).

 

I have a 2010 CVO Ultra Classic, not sure it the rear tire is the same size as yours or not....anyway, they first tire on the bike show cupping on the edges, and you could even hear it when you turned. Second tire I kept at 41 lbs air pressure never had a cupping issue. Coincidence??? maybe....kept track of the second tire air pressure more regular also.

 

Thanks fro the replies. To have all the tread scrubbed off in 6500 miles (just checked the install mileage) on only the left hand side of the tire is odd. Most if not all of that part of the tread should not be touching the road while traveling straight. I am going to replace both front and rear tires and have the alignment checked. I would think that if the swingarm was bent my other tires would have worn like this as well. I have checked tread depth on the front tire and there seems to be a little more wear on the right side of the tire although it is hard to tell with cupping starting to happen on the front as well. Thanks again and any input is appreciated.