wtf tire wear?

[blalor]

2007 R1200RT, 52k on the clock or so, Michelin Pilot Road 4 GT with 7k-ish miles on them, 2217 date stamp. I bought the bike (with these tires) about 5500 miles ago.   After a 3k mile trip up to and around Cape Breton this past summer I noticed that the tires (front and rear) are showing pretty severe scalloping. I’ve followed the recommended tire pressures in the manual pretty closely. The summer trip was solo, with full side and top cases, but (I think) it wasn’t overloaded. 
 

In my experience this kind of wear on the rear is unusual. Anyone have any ideas what caused it?  I’m ordering up a set of Road 5 GTs this week. Still some tread on these but I can hear them howl when leaned over a bit and the handling isn’t great. 
 

Thanks!

Brian

 

 

[TEWKS]

I know a guy on this board that would call that a new tire.   If you're not comfortable with the tire, yup good idea to go new and hopefully you'll have better luck. 

[blalor]

There’s definitely plenty of tread left (on the sides), but it’s squared off enough that the bike can’t decide what to do when tipped over just a bit. 😁

[w2ge]

Pretty typical in my book certainly re PR tires. 7k they’re scalloped. Fronts thrum terribly in corners by 3k.  
 

tbh, I’ve given up on Michelin’s on my RT...  YMMV
 

 

[blalor]

Good to know. Thanks!  Real curious how the Road 5s do. 

[GordonB]

No comments on what PSI was running. May be part of the problem.

[blalor]

Quote

 I’ve followed the recommended tire pressures in the manual pretty closely. 

 

So that's between 32 and 36 (loaded) for the front, and 36/42.1 rear.

[The Rocketman]

42 front and rear recommended by BMW and Michelin.

[Rougarou]

On 1/26/2020 at 1:11 PM, TEWKS said:

I know a guy on this board that would call that a new tire.   If you're not comfortable with the tire, yup good idea to go new and hopefully you'll have better luck. 

 

Not even remotely close to a wear bar.

 

And I don't see any white showing through,.....yep, still got an immense amount of tread left.

 

As for the scalloping,.....it's a PR, all of mine have done that.  Pressure up, pressure down, I can't find a happy pressure anywhere, so, I just ride 'til I see the white lines in the middle.

[MikeB60]

50 minutes ago, The Rocketman said:

42 front and rear recommended by BMW and Michelin.

The sticker on the bike and the manual on my 2006 RT and 2011 RT were 36 front and 42 rear.  Not sure about Michelin, love their truck tires not so much for the motorcycles.  

[Ponch]

32 and 36 is too low. I run 40/42...

[ed may]

I've been through several Pilots/several generations and they all scallop.  I wrote to Michelin and they gave me some copy and paste reply blaming it on my bike.  No help or even a response from an actual person.  I changed to Continental road Attack 3 GT.  I will never go back, love them.  Not sure if they will scallop, not many miles on them yet, but I love them.  The bike feels better than with the Pilots.  I have also been using Continentals on all of my cars.  You can't beat them.

 

[Rinkydink]

I have 7800 miles on my PR4s and they look the same. I pretty much run 39/43. Switching to Bridgestone T31 GTs on the advice of a lot of seasoned forum members here. We will see. 

[lkraus]

Looks pretty typical for a multi-compound tire.

The central tread is harder for longer life. It squares off a bit, especially with many freeway miles.

 

The rubber next to it is softer for better traction, but wears faster. The edges of the tire are also soft rubber but are normally used least and wear least. So the  portion of the soft tread right next to the hard center becomes somewhat concave, as it wears fastest. The wear in this transition/middle area is where my TWIs are exposed first.

The feathering on the edges of the tread blocks is also common. You'll notice that it can be different front and rear because the braking and acceleration forces are in opposite directions. The leading edge gets pushed under the weight of the bike, the trailing edge gets pushed into the gap between blocks where it cannot support weight and wears less. 

 

With Michelins (PR3 and PR4), I also developed some pretty pronounced "divots" (maybe 6?) - rather oval areas in the partial-lean areas around the circumference where the tread thickness became very wavy, and noisy. I'm using a Metzeler RoadTec 01 now, which has developed the concavity in the hard/soft tread transition area, but the tread depth remains consistent around the tire.  I don't remember any handling effects from the uneven wear on the PR3s, which I liked a lot. The PR4 never did feel as confidence inspiring as the PR3 and got a little worse as it wore.  The RoadTec has felt very good since day one, the concavity is not an issue. The tread still gets flattened to the road as it rolls. Tire life for all three has been similar, ~7500-8000 miles.

[dduelin]

The Road 5s rear tires use a significantly different method to delineate the harder center from the softer outsides that seems to make a big difference in how the tire feels and wears over it's life. Pilot Road 4s rears used a 20% width center and 40% on either side to make up the tread surface from edge to edge and the compounds were from surface to carcass with no blending. It's either' hard or soft' and the sections resemble pie slices in cross section. The Road 5s overlay the carcass from edge to edge 100% with hard compound and just the upper 17% to the outside edges are overlaid with soft compound, a layer of soft over hard with the soft section radiused on the inside to allow the tire to gradually or incrementally get onto the soft edges as lean increases. The middle section of hard compound is 66% wide where it is exposed to the road. The soft edges are supported at high lean angles with the underlay of hard compound. I really disliked the way earlier PRs changed feel as the tire was increasingly leaned over and of course they wore lumpy with divots and high spots. I swore off PR3s and went to Bridgestones in the BT023/T30/Evo years to the current T31s and steered as many riders as I could to them while poking Michelin in the eye every chance I got. Did I mention I really disliked Pilot Road tires? I'm a changed man, done a 180, repented, recanted former testimony! The 5's are very linear in feedback from edge to edge with the extra benefit of quiet symmetrical wear over life of the tire. You would think I work for Michelin now but I don't. These tires are a wonderful step forward in dual compound construction.

[Bernie]

Well Dave, you are not the only one that is liking the PR5 tires. In my case the GT version. I rode many miles with my Hexhead on PR3 & 4's, but what ever they changed from those to the 5GT versions, it made a huge difference in my opinion. 

As for those PR4 rear tire, you have a lot of wear left in it, I used mount tires like that  and ride until the center is bald.

[blalor]

I've got Road 5 GTs on there now and they're amazing, in comparison. It handles like a (big fat) sportbike, now, is stable in corners, tips in without drama, and is quiet and smooth.  There may have been plenty of life left in those PR4s, but it wasn't worth it to keep them.  I've had PR4s on a couple other (lighter) bikes, and I see them on Multistradas and Monsters around town and I've never noticed scalloping like that anywhere else.  With any luck I'll be able to get them on the salt at Bonneville this summer. 😁