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cupping

hadaveha

Guest
Guest
what would make my rear tire cup as badly as it has it has plenty of tread available.  I expected more out of pirrelli 
 
Poor damping.  Good tires will always show  suspension defects more so than harder  longer wearing - less expensive tires.                The tire has to absorb the  damping because the stock shock cannot (stock C10 shocks dont  have valves... they use antiquated emulsion tube technology) Very common issue with stock emulsion tube shocks.

You running the stock shock? Or have you upgraded yet? Progressive 465 is a good option for C10 (465 has valves- not emulsion tube)
 
ive never heard or seen that, and i run a lot of bikes 2x as old as the concours. (with sticks and twigs for suspensions) I mean, bad suspension isn't good but i've never seen it cause a tire to cup. I have seen new sport bikes cup tires pretty bad when a track day was done though, so the braking definitely has affect as mentioned, but most aren't stuffing the c10 late into corner 3.  :motonoises:

from Dunlop:

How can I keep my tires from cupping?
You may not be able to entirely avoid cupping. Tire cupping or irregular wear is a somewhat common occurrence on all vehicles. On a four-wheel vehicle, you are advised to rotate your tires periodically to even out wear. Unfortunately, you do not have this luxury with a motorcycle because front and rear tires, unlike those on most four-wheel vehicles, are not interchangeable.

However, there are steps that can be taken to minimize cupping and uneven wear on a motorcycle: Maintain your motorcycle and particularly your front and suspension. Avoid hard braking whenever possible. Braking causes the tire to grab and wear in one direction. When braking is applied to the front tire, the load transfer over-flexes the tire and increases the tendency for cupping and uneven wear. Maintain your tire pressures. Under inflation and overloading of motorcycle tires are significant causes of cupping and uneven wear, particularly in association with hard braking and/or trailer use.

Once a tire begins to show signs of uneven wear, even following these steps may not improve the condition.

Tire companies can, and are, helping to minimize cupping and uneven wear but you, the rider, must do your part. Following the aforementioned guidelines will help avoid uneven wear.

shown here:

https://www.dunlopmotorcycletires.com/about/faq/#faq-4
 
I have had cupping issues in the past also. I adjusted the suspension settings and went up on my tire pressures. So far on this set of Avon Spirit STs no cupping.
 
I think I figured out my problem,  the gage on my compressor is off by nearly 10psi.      The front in really new so it probably just hasn’t had time to start cupping yet
 
m in sc said:
ive never heard or seen that, and i run a lot of bikes 2x as old as the concours. (with sticks and twigs for suspensions) I mean, bad suspension isn't good but i've never seen it cause a tire to cup. I have seen new sport bikes cup tires pretty bad when a track day was done though, so the braking definitely has affect as mentioned, but most aren't stuffing the c10 late into corner 3.  :motonoises:

from Dunlop:

How can I keep my tires from cupping?
You may not be able to entirely avoid cupping. Tire cupping or irregular wear is a somewhat common occurrence on all vehicles. On a four-wheel vehicle, you are advised to rotate your tires periodically to even out wear. Unfortunately, you do not have this luxury with a motorcycle because front and rear tires, unlike those on most four-wheel vehicles, are not interchangeable.

However, there are steps that can be taken to minimize cupping and uneven wear on a motorcycle: Maintain your motorcycle and particularly your front and suspension. Avoid hard braking whenever possible. Braking causes the tire to grab and wear in one direction. When braking is applied to the front tire, the load transfer over-flexes the tire and increases the tendency for cupping and uneven wear. Maintain your tire pressures. Under inflation and overloading of motorcycle tires are significant causes of cupping and uneven wear, particularly in association with hard braking and/or trailer use.

Once a tire begins to show signs of uneven wear, even following these steps may not improve the condition.

Tire companies can, and are, helping to minimize cupping and uneven wear but you, the rider, must do your part. Following the aforementioned guidelines will help avoid uneven wear.

shown here:

https://www.dunlopmotorcycletires.com/about/faq/#faq-4

m in sc: I shake my head as I read this from your post "Avoid hard braking whenever possible." Did Dunlop really say that? OMG. The misinformation that goes around is astounding. Daytona Mike is the one person on this thread that is right. It's a rebound damping issue. I can't guess from here if it's too fast or too slow. The direction of the cup gives that away but I'm not going to try and get you to convey that to me. It's too likely that I will get misinformation and you will get wrong advice. Besides, there are too many secondary questions that follow from me. So here is the education you must undergo: https://www.youtube.com/watch?v=dVYSfIUnzBk
 
There is so much misinformation and just plain BS out there these days.
Just ask U-Tube.
It just does not make any since to me for Dunlop to tell someone to
avoid "hard braking", inferring that there tires are not as good as others
that don't cup. Sounds like complete internet BS to me.
Cupping on a rear tire is rather unusual. Rear axles on C-10 and 14 are
quite strong and do a very good job of keeping the tire aligned. That said
there is nothing that keeps the owner from screwing up the alignment.
Poor maintenance of swing arm system can cause a lot of unusual problems.
Check all the bearing and torque nuts and bolts. Make sure there is NO slop
in the bearings. And if the bike has been dropped or " the one I like" the bike
has been parked in front of your wife "girlfriend" car and she just nudged it
when pulling into the garage. Just stop and think how this can twist the swing
arm. And as has been stated suspension can have an effect. But since these
bikes are single shocks there should be equal pressure on both sides of the
swing arm. Best check the tire pressure and look at the way the tire is mounted
on the rim.
 
In my 50+ years worth of experience it's tire pressure and balance, suspension, alignment; in that order.
 
Thats directly from Dunlop, I disagree as well for the most part, not sure why they have that  on their tech info page. If you cant brake hard on an MC tires, to me, they are worthless. I was just pointing that out ans what a manufacturer said and maybe where some of the weird info comes from However, a lot of times for aggressive riding, the tires people use on large touring bikes aren't really suited for aggressive riding. its hard to get a mileage AND performance tire in one package.  That's just a fact, have seen that many times. Me, i don't care about mileage so i run the stickiest tires i can and always run the appropriate pressures for the bike and my weight, and check the pressures often.  But, as the OP stated in his reply, it was his pressure, as i suggested. (assuming everything else as jim stated is in good order as well). To note, i've had zero cupping issues with the avons on my c10 for the past 2.5 yrs, i ride it fairly aggressively and mixed riding, distance and local and some mountain runs 2 up. There is a lot of mis-information, but with tire life and health, usually it just boils down 1: to doing regular maintenance to keep them in good shape, 2: and running the right tire for your bike. .02
 
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