Rear tires cupping on a PR3

[Toaster]

I have 4900 miles on my set of PR3, and have noticed that the rear tire is cupping quit badly.
I have never had a tire on a MC do this before. I have run 42 to 43 lbs of air in the tires at all times.
What causes cupping?

 

[mcgyver74]

Do you burn a lot of slab?  My PR's have about 7000 on them and they are cupped but I run a LOT of highway

 

[zg]

No slab and no cupping here... I got about 5500 miles out of mine and they wore really evenly from lip to lip.

 

[B.D.F.]

Are you sure it is cupping or it is the leading edges of the tread blocks wearing down faster than the rest of the blocks? Because of the wide tread and odd angle of the tread, PR2s and PR3s wear such that there is a big 'drop off' between tread blocks near the center of the tire. Cupping is something different and will actually show different wear patterns in different tread blocks around the tire while normally, all the tread blocks are worn oddly but the same everywhere on the tire.

Tread block wear is uneven because the tire pushes the tread ‘out of the way’ a bit and the leading edge rolls under and is worn much more heavily than the trailing edge of the same block. Further, because the tread cuts are not parallel or perpendicular to the line of tire movement, the wear at the edge of the tread blocks tends to take on a curved pattern, making it look even stranger. In actual use though it does not make much different in how the tire performs although there may be a slight loss of traction in very particular circumstances- say hard acceleration when leaned over just enough to be riding across the tread line.

Brian

I have 4900 miles on my set of PR3, and have noticed that the rear tire is cupping quit badly.
I have never had a tire on a MC do this before. I have run 42 to 43 lbs of air in the tires at all times.
What causes cupping?

 

[mcgyver74]

Are you sure it is cupping or it is the leading edges of the tread blocks wearing down faster than the rest of the blocks? Because of the wide tread and odd angle of the tread, PR2s and PR3s wear such that there is a big 'drop off' between tread blocks near the center of the tire. Cupping is something different and will actually show different wear patterns in different tread blocks around the tire while normally, all the tread blocks are worn oddly but the same everywhere on the tire.

Thanks for the clarification, I guess I have tread block wear and not cupping

 

[Gypsy JR]

I do a good bit of slab, but I also do a good bit of twisty stuff too.

We did 6+ hours of twisty stuff at the Canaan event last Saturday. 

My PR3s are wearing but they are wearing evenly, sidewall to sidewall. All the way to the sidewalls edges.

 

[Just Cliff]

At 4900 mi. mine don't have enough tread left to cup!

Cliff

 

[Gypsy JR]

5,500 miles. Still good for NE Fall Foliage gypsy ride which is about 3 or so hours each way, plus some little day-long stuff.

I'll winterize with them still on and put new on in the Spring.

 

[Toaster]

Greetings
Thanks for the clarification on Cupping. After Brian has explained the issue about tire ware. I would say that my rear tire is not cupping, but tread block wearing. I live on a very hilly windy steep road. I often accelerate through the corners hard up the hill. (just having a little fun).
Thanks again

 

[slybonesjesse]

Are you sure it is cupping or it is the leading edges of the tread blocks wearing down faster than the rest of the blocks? Because of the wide tread and odd angle of the tread, PR2s and PR3s wear such that there is a big 'drop off' between tread blocks near the center of the tire. Cupping is something different and will actually show different wear patterns in different tread blocks around the tire while normally, all the tread blocks are worn oddly but the same everywhere on the tire.

Thanks for the clarification, I guess I have tread block wear and not cupping

Well I would like a better explanation of cupping then, because from what I have read all over the internet tread pattern wear is cupping. Most threads point to this link.

http://www.rattlebars.com/tirewear/

CUPPING:
Cupping, which is more accurately described as scalloping (see pictures, but we will use the more common term "cupping" here), is a natural wear pattern on motorcycle tires and it will always follow the tread pattern. It is not a sign that you have bad suspension parts. It merely shows that your tire is indeed gripping the road when you make turns (thank you for that Mr. Tire!). This cupping develops within the side wear bands of a leaned motorcycle. The extreme forces that come in to play when the bike is leaned in a turn are what produce the effect and when the wear becomes sufficient, one will experience vibration and noise when one banks into a turn. Upon examination of the pictures at left of our sample rear Avon, our dusted front VTX Dunlop D256, and the picture of our chalked Dunlop D206 one can see how the cupping follows the tread pattern. The leading edge of the tread does not flex much as it grips the road and the rubber is scuffed off the tire in that area causing a depression. As the tire rotates, the pressure moves to the trailing edge of the tread pattern where the tread flexes more causing less scuffing so less material is ground off the tire. The more complex the tread pattern, the more complex the cupping pattern will be. The softer the compound of the tire, the sooner this cupping will develop. Radial tires are more prone to cupping than are bias ply because the compound of radials is softer. As one can see, the simple tread pattern of the Avon pictured produces a simpler scallop pattern while the more complex VTX D256 Dunlop is somewhat involved, though still easily seen in our photo. Cupping on the Valkyrie Dunlop D206 is very hard to photograph because of the complex tread pattern. Low tire pressure will exacerbate this wear pattern and you will lose many serviceable miles by running low. Improper balance has nothing to do with cupping on a motorcycle tire. Improper balance will merely cause your bike to vibrate within certain specific speed ranges. 

 

[pistole]

+1 to the explanation above.

am just seeing it on the fronts of my stock b'stones , at about 5000 miles

.

 

[dalroo]

Careful with those OEM fronts - as has been discussed here several times, when they go, they go fast!

At 5,000 miles my front looked fine, and at 5,600 with chords showing I was afraid I might not make it home from an hour away. The good news is there are some really good replacement options out there.

 

[B.D.F.]

Well, if it is all over the internet then it must be true....  reminds me of the dangers of dihydrogen monoxide routinely made public only on the internet: http://www.dhmo.org/truth/Dihydrogen-Monoxide.html

I think the words are getting in the way here- tire cupping is abnormal, undesirable wear. Tread block wear or 'feathering' is normal wear although also undesirable. Perhaps the best example of cupping can be found on automotive tires rather than on motorcycle tires, and it absolutely does not follow the tire tread. Feathering always does follow the tire tread. At any rate, beyond the words, motorcycle tires do not generally wear down evenly or maintain their roundness as they wear. If that uneven wear is symmetrical to each tread block, it is normal and there is nothing to fix or adjust. If that wear does not follow the tread pattern but rather happens in a random fashion around the tire's periphery then something is abnormal, and should be found and corrected. The most common reason for cupping (asymmetrical tread wear pattern) is low tire pressure.

Brian

Are you sure it is cupping or it is the leading edges of the tread blocks wearing down faster than the rest of the blocks? Because of the wide tread and odd angle of the tread, PR2s and PR3s wear such that there is a big 'drop off' between tread blocks near the center of the tire. Cupping is something different and will actually show different wear patterns in different tread blocks around the tire while normally, all the tread blocks are worn oddly but the same everywhere on the tire.

Thanks for the clarification, I guess I have tread block wear and not cupping

Well I would like a better explanation of cupping then, because from what I have read all over the internet tread pattern wear is cupping. Most threads point to this link.

<snip>

 

[gsun]

I had a look at Toasters tire wear and it is tread block wear. Maybe....I think....or cupping.  ;D

 

[pistole]

- my "wavy" wear appears dead-on-center of my stock B'stone front tire. That's cupping. And I am religious in my maintenance of 42 psi for front and rear tires.

- but I do alot of highway miles at highspeeds.

- and as if on cue , I am now getting a strange vibration coming from the front end.

- my service guy (as he was replacing my rear shock under warranty for a seized pre-load adjuster) noticed the front tire first , and said that the stock tires were prone to that and recommended Pirelli Angel STs for the next set of rubber.

- i mentioned the much internet-forum-vaunted tyre : Michelin Pilot Road 3s and he swore.

- his opinion : at "normal" speeds and in the wet , they're fine. But at high speeds , there is a definite instability in the PR3s that resulted in some owners bringing back the bikes + tyres , and asking that the tyres be taken off immediately although they were almost new.

- when I asked what sort of speeds did the instability start , he mentioned 100 mph (160 kmh) and above. So , maybe read into that what you will , ie , if you never see upwards of 100 mph , then maybe the PR3s are great.

cheers

.

 

[stewarth]

I've ridden 2 Trackdays on my PR3's and they have been rock solid rim to rim and worn a rear out completely. Not sure why the dealer would say such a thing, but I'm happy.

 

[Gypsy JR]

I don't do track days any more, and if I did, it would not be with a C14. But I get your point, and agree.

I have ridden my 2012 with PR3s on it since the day I picked it up in January hard, with a heavy dose of slab and an equal dose of mountain road riding. Enough to wear the tires, front and rear, evenly from sidewall edge to sidewall edge. Around many turns where the pegs were being beveled by the pavement, and she was squatting down on the suspension big time due to turn forces. And not once did she shimmy, slide, or do anything but stay neutral, predictable, and balanced.

And after 5,500 miles, those PR3s are still good to go.

Anyone that says PR3s don't provide track-quality traction in turns is either comparing them to track slicks (or track rain slicks) or blowing smoke out their arse.

 

[pistole]

.

- iirc , nobody is questioning the dry/wet grip of the PR3s.

- its high speed stability that is in issue.

- with due respect : have noticed that on your US based forums , riders almost never get to ride fast for long distances because of the law enforcement.

- where I am from , long distances on highways at v. high speeds (we cruise at 100 mph , and regularly touch 110/120) is common.

- on some of the bmw forums (where some riders can take their bikes to the continent and run them fast) , they are beginning to mention this high speed instability of the PR3s and in fact , Michelin have deleted a certain big/heavy BMW sport-tourer from being approved for use with their PR3s.

.

 

[stewarth]

Which BMW? Why didn't you name it?

 

[boomer]

Poppycock and balderdash!

I have regularly do short bursts to 140Mph and have done one sustained run at 150Mph (30-40 minutes) and the PR3s are fine.
Since I don't live in a TuV country I can run these tyres and on the Autobahn they perform perfectly.
They are ROAD tyres and yes they are designed for wet conditions, but they are W-rated which means safe to 168Mph.
I had no squirming or wobbling or other instability. Planted and stable the whole time.
At the time I did the Autobahn run the tyres had about 2k miles on them as had just replaced the PR2s with PR3s.
In fact they feel exactly like a PR2 unless yer riding in the rain. Then they feel way better. :great:
My only problem was that cornering at 150Mph is HARD WORK! The bike REALLY does not want to lean at those speeds.
The PR3s were far better than the OEM crap that I had fitted the first time I hit 150Mph on the A3 between Frankfurt & Bonn.

Michelin have never recommended a tyre for the K1600.
They used to have it listed on their UK website but that was an error and it was pulled a couple of months ago.
They have NEVER tested the K1600 with any of their tyres so do not recommend anything.
That said, one of the UK 1400GTR forum members who now has a K1600GT has fitted PR3s to his and loves them, and he has also been for a play on the Autobahns with the PR3s.

Are the PR3s perfect? Hell no.
Are they better than any other tyre out there for the C14. Hell yes.
Better wet grip than the PR2.
Better mileage than the Angel ST.
Way better mileage than the Z8.
Way way WAY better than the BT021.
Can't comment on the BT-023 as I won't buy Bridgecrap ever again following several bad experiences of which the 021 was just the latest.
Roadsmart 2 may be an equal but haven't tested it yet and haven't heard anyone raving about it like they did when the PR3 came out.
PR3 are more expensive but IMHO worth the extra. Your Opinion May Vary. 

 

[Fred H.]

My last set of PR3's wore the rear tire very badly on one side only.