Front Tire Cupping?
rmclarty
Posted 2010-04-26 9:43 PM (#58446)
Subject: Front Tire Cupping?


Cruiser

Posts: 261
Sugar Land, TX (Outside of Houston)
I have the stock tires on my 08 Tour and just turned 10,000 miles this weekend (I know - I need to ride more).

Anyway, the front end has been kind of "Squirrley" on low speed left turns for a month or so and this weekend on a Texas Hill Country Ride my left turns at speed really felt "Off".

We noticed at a stop that the front tier had cupped or worn more on the left side of the tire and a small ridge had formed about 1.5 inches from the left sidewall. Obviously the issues I had was when the tire transitioned from the center of the tire over the ridge to the left side.

I suppose it could be because my riding has been mostly city and no hard twisties and the cheap ass stock Dunlop tires on it just wore to fit the natural slope of the road.

But a buddy said that one of the forks could have a small leak and have less fluid in it which would cause the odd wear. Have not noticed a leak in the garage but who knows.

Long story short - after 2 days of hard riding and twisties the ridge wore down enough to make it more comfortable to handle in fast left turns.

Anyone have any experience with the front forks being mis-aligned or out of whack?

I'm gonna replace the tires before my next big ride but I wanted to get the Dealer to check the front end if there are known problems.

Richard
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Arkainzeye
Posted 2010-04-26 10:06 PM (#58448 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 3773
Pittsburgh, PA
Air pressure 40 psi . Anything less cups for me. Sorry to be so short. I'm replying from a phone. Lol
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buzz64077
Posted 2010-04-27 9:57 AM (#58459 - in reply to #58448)
Subject: Re: Front Tire Cupping?


Cruiser

Posts: 215
orrick, mo
Keeping the air pressure right helps alot. I also vary where I ride on the road. A motorcycle has 3 lanes and I will use them all. I had a VTX that was real bad about cupping until I started varying where I rode.
I wonder if dyna beads might also help with cupping. I've got over 14000 miles on my stock front without any cupping.
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varyder
Posted 2010-04-27 10:02 AM (#58460 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 8144
New Bohemia, VA
air pressure 40+ and make sure you don't have too much in one saddle bag verses another.
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VisionTex
Posted 2010-04-27 10:30 AM (#58462 - in reply to #58460)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 1484
LaPorte,Tx.
This is from the Dunlop website and may give you some hints on tire cupping and the reasons.

http://www.dunlopmotorcycle.com/infocenter_faq.asp?id=9#faq
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cw1115
Posted 2010-04-27 11:40 AM (#58464 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 1290
Ruskin, Fl
I just noticed that my rear tire was cupped while adjusting my belt. I had 40 psi in there and lowered it a few pounds. More is better?
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varyder
Posted 2010-04-27 11:43 AM (#58465 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 8144
New Bohemia, VA
lower pressure, below 40psi shorten tire life, creates uneven wear patterns and handles funky for me. I don't about anyone else.
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cw1115
Posted 2010-04-27 11:46 AM (#58466 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 1290
Ruskin, Fl
Thanks. I like the pressure a little higher too. After the dealer replaced both tires last year if felt like I had power steering. Idiot had over 70 psi in the tires. Lowered down to 40 after one day and was happy.
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Teach
Posted 2010-04-27 5:14 PM (#58506 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 1436
cw1115, the rear will wear a feather pattern if viewed fron a side angle toward the center. This is due entirely to tread design and how that tread contacts the road surface. Folks who are use to the old Dunlop 400 series find it strange to look at but this is common to tires like the E3 and Avon tires that run a similar tread pattern.
As to the feathering on the front tire? Agree with the others, 40 psi and vary which section of road you ride (outer, inner and center). I will caution folks to look closely at the E3 front tire. The center strip is a harder compound and does not wear as quickly as the tire on either side of the 1" center strip. If you ride a lot of twisties as I do, you can be below the wear bars in the two areas mentioned and still look real good everywhere else on the tire. This can give you some real good butt pucker if you hit a tight corner hot and don't know you are low where you need the most grip.
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Man314
Posted 2010-04-27 6:20 PM (#58512 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Tourer

Posts: 575
Spirit Lake IA "Birthplace of Victory Motorcycles"
I've been running 37 psi on fronts and 40 psi on rears and I ride alot of 2 up . . . I have notices some moderate cupping. Have a Doran pressure monitoring system. I notice once tires heat up, my pressures rise ~7-9 psi . . . I guess that makes sense as the air expands when heated. Made me wonder if there is a max tire pressure once it heats up? Any thoughts. Can I safely increase a few psi (40 f - 42 r) and still be good?
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victoryvisiontour
Posted 2010-04-27 7:31 PM (#58521 - in reply to #58446)
Subject: RE: Front Tire Cupping?


Iron Butt

Posts: 763
Anderson, IN (48mi NE of downtown Indianapolis)
Teach,

Thanks for the front tire wear info. Now everything makes sense. I couldn't figure out why the sides are wearing, but not the center. It's starting to look like the front tire on a farm tractor.
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nightvision
Posted 2010-04-27 9:51 PM (#58533 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Cruiser

Posts: 156
dinwiddie, va
As to the original question, the front forks are impossible to have out of align and making the tire wear funny. The fluid level won't make any difference either. Fluid doesn't have anything to do with ride height or anything. It only effect your compression and rebound of the forks. Like others say, the only culprits are low tire pressure and how and where you ride
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cw1115
Posted 2010-04-27 10:44 PM (#58539 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 1290
Ruskin, Fl
Thanks Teach. This is the most miles I've gotten on a rear. The first two tires got flats at around 7K and were replaced. I guess that's why I never noticed it before. And you are correct about the front. I guess I make alot more hi-speed left turns, which makes sense since we drive on the right. When I replaced my orig front it was completely bald on the left side only.
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Teach
Posted 2010-04-28 9:17 PM (#58632 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 1436
cw1115, lots of folks are seeing FAR more miles than I, maybe I replace sooner than others, but on average I've gotten 10k from each rear E3. I ran 17500 on the front but it should have been replaced at 15500 but I wasn't paying attention to the areas just right and left of the center until I experienced slip issues. I've tossed on Avon Cobra's front and rear so I'll post when I've worn them out. So far they look really good with 7k on each, little to no signs of wear, usual rear feather, but no front tire ridge in the center (single compound tire). Enjoy......
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pollolittle
Posted 2010-04-29 8:35 AM (#58669 - in reply to #58446)
Subject: Re: Front Tire Cupping?


Visionary

Posts: 2027
Brighton, TN
I agree with Teach, man that dude likes to share an opinion, most are right and fairly poignant. Just the facts Ma'am just the facts. I was thinking of typing the same thing as him, but he beat me to the punch and used the Queen's language quite well. So, instead, I'll just shoot a warning shot across his bow, and tell him top of the morning, to ya, and a Job Well Done! In the Navy this would have been written in only red ink, the Captain was the only one allowed to use red ink.
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