Tire wear

[Sot1200]

My tires on my 1200 GSA develop a stepped PROFILE especially at the sides of the tires where the leading edge of a rubber block is thinner than the end of it making the roling of the Tire lumpy and feel of the tires at lean angles quite edgy. Is this down to pressures or the way I ride? Suspension has been changed to wilbers and run normal pressures as per manual. This has been gowing on for as far back as I can remember. Any thought???

 

[AustinW]

Front tyre? Looks like the tread blocks are scalloped? If so it's usually down to cornering, specifically front braking into corners. Used to happen to me on whatever bike I ride. Now, I try not to brake at all for corners using engine breaking and anticipation instead and butt clenching if i get it wrong. Tyres always now keep a nice even profile.

If it ain't the scalloping then I don't know.


Sent from my iPhone with a smile

 

[Beemerman59]

My tires on my 1200 GSA develop a stepped PROFILE especially at the sides of the tires where the leading edge of a rubber block is thinner than the end of it making the roling of the Tire lumpy and feel of the tires at lean angles quite edgy. Is this down to pressures or the way I ride? Suspension has been changed to wilbers and run normal pressures as per manual. This has been gowing on for as far back as I can remember. Any thought???

What make/type of tyre?

 

[itspilsbury]

I had exactly the same issue with the rear tyre of a Pilot 3, I showed it to an examiner from VOSA he thought it might be suspension, tyre pressure, wheel balance or faulty tyre. I sent it back to Michelin and they said that it was not a tyre defect it was either incorrect tyre pressures, poor wheel balance or worn suspension. As my bike was fairly new with about 11k on it I dint think it was suspension so before I sent it to Michelin I checked the wheel balance, it had a half ounce weight on the rim ON THE HEAVY SIDE - wrong side so was an ounce out of balance. I always check my tyre pressures and as I'm 16st ish I inflate them to the loaded pressure as the Pidcocks salesman told me.
I have seen other GS bikes with similar wear though.
So I would just check how well balanced the tyre and wheel is.
I always fit my own and balance them after this experience.

 

[Bendy toy]

My brothers Aprilia Pegaso and MZ250 always wore their tyres like this (fronts especially) when he lived in Italy. He regularly rode in the Alps with lots of hairpins an turning going on. The shoulders wore of long before centre treads. The tread blocks always wore faster on the trailing edge so ended up like saw teeth.
My bikes do the same but to a lesser extent. Pressures are 36/42.

My personal belief (because I can't find any official information) is the tyre tread block hits the road and bounces a mm or two. It rebounds back but tyre has moved on so the back end of each tread block gets pressed harder into the road than the front.
I've had the same on sporty car tyres so I suspect the compound has an effect. Softer compounds bounce further so get more angular stepping than harder compounds.
The Maxxis SuperMax I had on the Yamaha did 15K on front and 8K on rear. Pretty much double the miles I got from Conti Road Attacks.
They all stepped but the Cont was much worse. The front Maxxis also rounded the tread leading edges so became dodgy in the wet before it measured as worn out.
The rear Maxxis kept a reasonable profile shape on a bike noted for squaring it's tyre. The middle was really smooth. Shoulders marbled and stepped.

 

[The bigun]

My brothers Aprilia Pegaso and MZ250 always wore their tyres like this (fronts especially) when he lived in Italy. He regularly rode in the Alps with lots of hairpins an turning going on. The shoulders wore of long before centre treads. The tread blocks always wore faster on the trailing edge so ended up like saw teeth.
My bikes do the same but to a lesser extent. Pressures are 36/42.

My personal belief (because I can't find any official information) is the tyre tread block hits the road and bounces a mm or two. It rebounds back but tyre has moved on so the back end of each tread block gets pressed harder into the road than the front.
I've had the same on sporty car tyres so I suspect the compound has an effect. Softer compounds bounce further so get more angular stepping than harder compounds.
The Maxxis SuperMax I had on the Yamaha did 15K on front and 8K on rear. Pretty much double the miles I got from Conti Road Attacks.
They all stepped but the Cont was much worse. The front Maxxis also rounded the tread leading edges so became dodgy in the wet before it measured as worn out.
The rear Maxxis kept a reasonable profile shape on a bike noted for squaring it's tyre. The middle was really smooth. Shoulders marbled and stepped.

Its the last thing id want whilst cornering my tread blocks bouncing a few mm off the road although i did have a pair of trainers wear oddly when i used to skip to work if that helps

 

[Sot1200]

As I said both front and rear do scallop. Happened w trail attacks battlewings and now TR91s. Roads where we ride are twisty w very little highway involved. I do Carry some spped in the corners and am a bit stiff on the saddle especially when pushing on as if grabbing on a raging bull. Do you think increasing or decreasing Tire pressures would do anything? or its best to try to relax more on the saddle and let the bike do its thing in the corners rather than try ot wrestle it around?

 

[Martyn H]

You say in your OP that the tyres pressures are set "as in the manual" - what pressures are you using ?
I have alway maintained that the right source of info about tyres & tyre pressures, is the relevant manufacturer, be it Conti, Metzeler, or so on.
As you imply you're currently using Dunlops, they recommend 36/42 PSI front & rear, so that might be a good place to start, although it won't make a distorted tyre as good as new.

 

[Beemerman59]

I've always had heavier wear on the leading edges of the raised blocks with the "Adventure" style of tyre such as with Battlewings and Conti Trail Attacks. Thats on both front and rear. No such uneven wear on road tyres such on Roadsmarts and PR3's. I just put that down the extra stress from braking and acceleration, therefore wear on those types of tyre. As to replacement wear, I'm pleased if I get above 5K on a rear, double on the front.

 

[eggsy]

Tyres - Tourance EXP's

I've had three sets of Tourance Exp's and they have all done this. Mate of mine has the same on Michelins. I think its just the way some tyres wear. I've never had an issue with them. I dont brake into or during cornering. My pressures are virtually correct as I check them all of the time. It;s just one of those things.

 

[Sot1200]

use the BMW manual so its 32/36psi. Tried once higher pressures but found ride harsh. I will work on my riding most probably.

 

[Beemerman59]

use the BMW manual so its 32/36psi. Tried once higher pressures but found ride harsh. I will work on my riding most probably.

You have already said in your opening post that you don't like the handling at those pressures - they feel "edgy" when the bikes' leaned over. Its worth a bit of trial and error here as adding a few psi to front and rear from what you have them set to now is unlikely to cause any negative affects. For whats its worth I run 36/42 in the summer on my GSA which is running PR3's and drop those to 34/40 in the winter. I have tried 32/36 but the bike squirms all over the place despite that being BMW's recommend pressures. Go with the manufacturers recommendations as a start and then play around with them a bit.

 

[Bendy toy]

Its the last thing id want whilst cornering my tread blocks bouncing a few mm off the road although i did have a pair of trainers wear oddly when i used to skip to work if that helps

Sorry for dumbing it down too much.
Rubber compresses and bounces back (unless its been deep frozen). My guess is the push back is just enough to cause more wear on the the training end of the tread block than the leading edge.

Swap "bouncing" for "reverberating" or "rebounding" or any other adjective you like and Post 5 might make sense.

 

[Martyn H]

use the BMW manual so its 32/36psi. Tried once higher pressures but found ride harsh. I will work on my riding most probably.

Try the tyre manufacturers recommendation for pressures; Dunlops ? 36/42

 

[JohnnyBoxer]

use the BMW manual so its 32/36psi. Tried once higher pressures but found ride harsh. I will work on my riding most probably.

Too low

36/42 is correct & recommended to me by Metzeler in Germany

 

[Bendy toy]

I use the tyre manufacturer's recommended pressures 36/42. The stepping Ive seen on my other bikes happened at 36/42. The BMW does it but less badly than the Yamaha, so maybe the suspension (especially the front) has an effect.

 

[Packer]

The big blocks and deep channels in dual sport tyres mean that the blocks deform a lot, being smooth through the corners with slight drive will minimise it. Consistently accelerating heavily through corners or braking into corners will alter how the blocks wear substantially. On Heidenau K60's what starts as rectangular square edged blocks wear to triangular sections. They still grip just as well, in the dry at least.

You can see how the blocks have deformed and polished the carcass on this image

Here you can see how what started as a squared block is almost a triangle