Michelin Pilot Road 4 GT on ST1300 - scalloping @ less than 4k...

Joined
Sep 30, 2015
Messages
37
Location
USA
Hello All,

Looking for some input and guidance on the way my rear tire is wearing - it is exhibiting significant scalloping on both sides.

It was installed in early October, along with new matching PR4 for the front. I have been very diligent in maintaining exactly 42psi, and of the the ~3,700 miles ridden thus far, about 600 has been two up. Either alone, or with a pillion, I am hardly an aggressive rider. But over the past five months, I have enjoyed the curvy mountainous roads around Albuquerque. I have been practicing techniques as part of essentially re-learning to ride - after a 25 year sabbatical.

My current operating theory is that this odd wear happened as a result of an improperly maintained rear shock pre-load adjustment. I fixed this two weeks ago, and the bike really handles and rides much better. Until then, frankly, I was beginning to believe I would be forced to replace the rear shock/spring. I weigh 240 pounds, and began to surmise the stock shock was just not designed for someone my size. But I now think the stock set up is reasonably fine. I'm unsure if the lack of any preload before is responsible for the scalloping. Could running the suspension near its upper (bottomed out) limits cause this? Appreciate any thoughts...

Best,
Rocky
 

ToddC

Site Supporter
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Feb 2, 2015
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60
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Seven Bays Wa
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2006 ST1300A
Acceleration in corners during practice ???????:)

Just a thought.......


ToddC
 
Joined
Sep 22, 2015
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1,287
Location
Wasaga Beach, Ont. Canada
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'04 ST1300 Blue STar
The scalloping is limited to the rear,,, right ?? I am thinking that a soft (no preload) rear suspension would allow extra travel in the twisties. You have fixed that now,,, but what about the rebound adjustment ?? That would limit the amount of bounce under loads. Have you also made adjustments there ?? Just thinking out loud,,, Cat'
 
Joined
Dec 20, 2013
Messages
8
Location
bakersfield, ca
Bike
2008 ST1300
I ran pr2 and currently pr4, I do a lot of spirited mountain riding. The cupping is do to the hard throttle input on corner exit, I am getting about 6k miles out of the rear tire. I have a friend that has race tech suspenson on his st1300. he still has cupping problems but also rides very aggressive. If you ride a heavy bike on primarly in the curves you will get cupping.
 
OP
OP
Joined
Sep 30, 2015
Messages
37
Location
USA
The scalloping is limited to the rear,,, right ?? I am thinking that a soft (no preload) rear suspension would allow extra travel in the twisties. You have fixed that now,,, but what about the rebound adjustment ?? That would limit the amount of bounce under loads. Have you also made adjustments there ?? Just thinking out loud,,, Cat'
I did perform the rebound adjustment at the same time I fixed the preload. I sounds like it may simply be a fact of life for me - that I probably won't get the 10k miles I had hoped for from the rear...
 
Joined
Sep 22, 2015
Messages
1,287
Location
Wasaga Beach, Ont. Canada
Bike
'04 ST1300 Blue STar
I believe that the PR4 is a dual compound tire,,, with the longer wearing silica tread in the center. Since you are getting scalloping on the softer edge area's,, the best way to achieve you 10k goal is to take some long road trips !! My last tour to the maritimes was about 3000 miles, with my CB1000c fully loaded,,, and I flat spotted the rear D404 doing it. That tire is much less sophisticated and was about half done before I left. But it should still get me through limited duty this season. And, it will have delivered about 8k miles, of combined driving. One other thing worth mentioning is that it is balanced with beads, which has worked very well in this instance. Cat'
 
Joined
Jan 27, 2012
Messages
18
Location
victoria Australia
Hi there . Myself and a few other riders over here in Australia have the same problem with the pilot 4s.l have 5000 kms and the rear has scalloped on the Rd high side.another mate has done only 1000 kms and his has scalloped really badly on both sides.and the other bloke has done only 13000 kms and both tyres are rat ****.It has got nothing to do with suspension and we all run 42 psi.and are conservative riders! It's just the Tyres
 
Joined
Jun 5, 2012
Messages
94
Location
Horseheads, NY USA
Bike
2003 ST1300
I have not found a tire that lasts more than 6000 miles on the rear. I don't tend to get scalloping, just run out of rubber. I am also a big guy and my wife generally rides with me only on trips. Our trips are always on curvy roads, since we avoid highways.
In addition to riding style, weight and road composition must affect tire wear dramatically.
These heavy, good handling bikes can eat up tires!
 

wjbertrand

Ventura Highway
Joined
Feb 8, 2005
Messages
4,420
Location
Ventura, CA
After years of riding and using literally 100s of tires on STs and other bikes, I find I get about the same mileage on all of them. On my ST, I routinely beat 10K miles on the rear and more than that on the front. I am not that conservative a rider. I know others riding the same bike in the same environment with the same tires that only get 5-6k miles. Beats me...


-Jeff
 
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