Front tire wear problem?

Beemer · 10-25-2011, 01:49 PM

Hi guys,
BMW Motorrad sponsored a track day event this past weekend for all our S1 owners at our local track (Kyalami-also hosted a few WSBK in the past).
Anyway after doing some sessions I noticed my front tire was wearing down much worse compared to my back tire IMO. (See attached pics of front and back tires)

Any ideas what the reason/s could be?

Tires are Michelin Power Pure's. Pressure set to 2.1 bar front, rear 1.9 bar.
My Stock suspension settings:
Preload - 4 lines showing
Rebound - 8
Compression - 6

**1000RR** · 10-25-2011, 02:40 PM

Doesn't look bad to me... just looks like you picked up some tire boogers. At least that's what I've called them. Rubber from other tires left on the track and because you're tires heated up pretty hot, the pieces of rubber stuck to your tire - tire boogers.

And your back tire does look like it has worn more than the front - which is expected.

Pinned · 10-25-2011, 03:01 PM

I had the same problem beemer, except it was my rear tyre taking the beating. I had a talk with Rob Holder and he sugested 1: running a bit more compression on the shock. 2: Deftating the tyre a bit more.

Now I know its on the rear that I was having the problem, but it may work on the front aswell. Oh ya, and my tyre pressures were all wrong, front was 2.2 and the rear was 2.4 bar. Metzeler K3's

S&Kmotorrad · 10-25-2011, 04:44 PM

Quote:

Originally Posted by Beemer

Hi guys,
BMW Motorrad sponsored a track day event this past weekend for all our S1 owners at our local track (Kyalami-also hosted a few WSBK in the past).
Anyway after doing some sessions I noticed my front tire was wearing down much worse compared to my back tire IMO. (See attached pics of front and back tires)

Any ideas what the reason/s could be?

Tires are Michelin Power Pure's. Pressure set to 2.1 bar front, rear 1.9 bar.
My Stock suspension settings:
Preload - 4 lines showing
Rebound - 8
Compression - 6

i had the similar problem with tire worn like that on my track day on Oct 2nd, and from my 21st track day this month, these look like these

I would loosen up the rebound....a notch to 7 and get some more info.

it took me whole morning and partial afternoon to dial in. I really need to shorten my tunning phase...

S&Kmotorrad · 10-25-2011, 04:45 PM

on a side note:

different tire would have different set up...

i was running 30/30 hot

i want to try 32/30 hot next time...

**AMRRA12** · 10-25-2011, 05:33 PM

looks to me that you have a rebound issue on the front

S&Kmotorrad · 10-25-2011, 05:46 PM

Quote:

Originally Posted by AMRRA12

looks to me that you have a rebound issue on the front

agreed...!!

S&Kmotorrad · 10-25-2011, 05:50 PM

another pre-requisite: did you set your rider sag?

**1000RR** · 10-25-2011, 06:15 PM

Could be some rebound... but damn that is pretty hard to see. I usually see more of a presence further to the left of those circles when it has become an issue.

Beemer, is that what you were talking about or were you just looking at all the excess rubber stuck to your tire?

**AMRRA12** · 10-25-2011, 07:03 PM

Quote:

Originally Posted by 1000RR

Could be some rebound... but damn that is pretty hard to see. I usually see more of a presence further to the left of those circles when it has become an issue.

Beemer, is that what you were talking about or were you just looking at all the excess rubber stuck to your tire?

the smoth triangle patches are usaly an indacation of a rebound issue and if you look the leading edge of the siping (tire groves) is worn down
here is the problem with "reading a tire" off just a picture and not having direct contact with the bike and or feed back with the rider:

A) we don’t know the track conditions from that day
B) don't know the outside temp
C) we don’t know how hard the rider was pushing it ( the faster you go the faster the suspension need to react)

so this could be a rider riding at 70% of his ability push that up to 90% the tires issue may go away

suspension set up is a very proactive job