• Can't post after logging to the forum for the first time... Try Again - If you can't post in the forum, sign out of both the membership site and the forum and log in again. Make sure your COG membership is active and your browser allow cookies. If you still can't post, contact the COG IT guy at IT@Concours.org.
  • IF YOU GET 404 ERROR: This may be due to using a link in a post from prior to the web migration. Content was brought over from the old forum as is, but the links may be in error. If the link contains "cog-online.org" it is an old link and will not work.

Shinko rear tire cupping

C

capmfries

Guest
Guest
Hi all!!...I have a 1998 Concours...bought a shinko rear tire 2 summers ago, only have put 4000mi on them...First summer was fine, next summer I noticed some cupping on the outer edges...In the past I ran my tires at the specs on the tire..last summer I ran at manufacturer specs...not sure which might have caused it...but am I still safe to ride?..can the cupping naturally go away?..I still have tons of life on them so I don't want to have to buy a new one.
 
Some one else can speculate on why it happens..
Here is what I found that will help.
http://forum.cog-online.org/tiressuspension-c10/cupping/

To get some more life out of the tire, a fix is; a fix is;
  Put the bike on the center stand and elevate the front tire.
  Give the tire a good spin and see if it spins easily..
    (If no, take the calipers off so that it spins)
  Use a body sander and reshape the cupped area as the tire spins to reshape the tire.
    Hold the grinder at approx. a 45* angle to the tires rotation {to spin and sand}..
      (You can't get it completely smooth, but can remove the high places)...

Yes, I know your removing rubber, but not the center rubber...
And; it's better than throwing the tire away..

Ride safe, Ted
 
From your post you said "brought a Shinko rear tire" that's not what you will fix
by grinding rubber off the front tire. Also you should not have to remove the
calipers to spin the wheel. If so you should find out why they are dragging.
 
OOps…

For the rear: Put bike on center stand, rear wheel up, crank engine and put in gear, let er' spin and grind.

The front remove the calipers is to make it extra EZ to spin.
ie; Don't want to grind grooves as you start it spinning.

Talking only about removing the higher edge's.
Minimal grinding there, won't make the tire unsafe..
Excessive grinding could, but a sanding disk won't remove much material..

This is a fix, not a cure for what caused the cupping.

Ride safe, Ted
 
I never said anything about calipers or anything dragging..the wheel spins free..the cupping happened over two summers of riding.
 
I've tried avons..they cracked...brought them back...and they cracked again...i'm done with avon...I'll try something different again...but even shinkos shouldn't cup with 4000 miles on them. besides...I love how the shinkos handle :)

 
Really...so it's common for tires to crack after 2000mi?...back to back? Wow!! I guess I've been lucky in the past....and it was the avon that cracked...not the shinko
 
date code on the side of the offending tires?
no matter, I removed my posts. sorry. I can't really give anything to make you feel better.
I'm out.  ride safe, get new tires, and social distance.

peace.
 
Ive never cared for shinkos in general, even though i have a set on one of my bikes (not the concours).

ive -never- had an in-date avon give me a premature cracking problem, then again i always check date codes. Make sure you run the tire at the pressure dictated on the bike, not the tire.  .02
 
You should try contacting AVON, they might help you out in good faith on a new pair?  As for the cracking, they (AVON) might not put enough UV inhibitor in the compound?  Years ago there was a big recall on rubber valve stems that were made in China.  The rubber where the valve stem seals on the wheel was cracking prematurely because they left the UV inhibitor out.  In some cases when you applied a little pressure to the valve, like putting air in it, the stem would snap right off.
 
TireguyfromMA said:
You should try contacting AVON, they might help you out in good faith on a new pair?  As for the cracking, they (AVON) might not put enough UV inhibitor in the compound?  Years ago there was a big recall on rubber valve stems that were made in China.  The rubber where the valve stem seals on the wheel was cracking prematurely because they left the UV inhibitor out.  In some cases when you applied a little pressure to the valve, like putting air in it, the stem would snap right off.
Click to expand...
Oh how I remember those valve stems.  I took my parents and my sister to Missouri during that time in the Roadmaster.  I'll shorten the story a bunch.  During that week long trip, I had three of the four fail!  Dad and I got pretty quick at swapping wheels out on the side of the road.
 
As far as the cupping on the rear, is the rear shock stock? You have a 22 year old motorcycle, things will wear out or not work as they use to over time. Consider upgrading the rear shock to a Progressive 465 (or other newer shock) and upgrading the front springs if you have not done so. Upgrading the rear shock on my '02 was a tremendous improvement to the ride and I never noticed my rear tire cupping again but I had upgraded the front springs and had a fork brace on long before I upgraded the rear shock. I should have upgraded the rear when I upgraded the front. And if you don't have one, put a fork brace on the front.

Also, make sure you know how to tighten the stem head nut properly. I tore my '02 apart several times chasing my rear tire swaying and it ended up being the stem head nut needed tightening, took me a while to figure out the front can affect the rear.

The above was my experience with my '02, it may or may not solve your issue, but it did in my case. Free advise is pretty much worth what you pay for it.

Good luck!

 
MotoCommuter said:
As far as the cupping on the rear, is the rear shock stock? You have a 22 year old motorcycle, things will wear out or not work as they use to over time. Consider upgrading the rear shock to a Progressive 465 (or other newer shock) and upgrading the front springs if you have not done so. Upgrading the rear shock on my '02 was a tremendous improvement to the ride and I never noticed my rear tire cupping again but I had upgraded the front springs and had a fork brace on long before I upgraded the rear shock. I should have upgraded the rear when I upgraded the front. And if you don't have one, put a fork brace on the front.

Also, make sure you know how to tighten the stem head nut properly. I tore my '02 apart several times chasing my rear tire swaying and it ended up being the stem head nut needed tightening, took me a while to figure out the front can affect the rear.

The above was my experience with my '02, it may or may not solve your issue, but it did in my case. Free advise is pretty much worth what you pay for it.

Good luck!
Click to expand...
I thought I was going to buy a new 465 shock from murph until he told me a couple of days ago that they are discontinued.  I just bought a used one today on ebay.  Hope it's a good one!
 
You must log in or register to reply here.
Top