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N/A | National Shocking tyre wear

Discussion in 'Racing, Motorsports, and Track Days' started by raven, Mar 21, 2013.

  1. The photo below is a brand new Pirelli Supercorsa (SC2), after only 2 sessions at P.I.
    This exact same tyre wear was evident on the previous Metzler Racetek's, so it's fair to assume it's not the tyre.
    The new surface is extremely abrasive (incredibly grippy), but that would explain increase in tyre wear...NOT the type of tyre wear, which is the thing that has me baffled. I've never seen anything remotely like this before.

    The tyre was warmed up over a medium paced lap before I got stuck into it, and as the previous tyres were run on a 35C day, and these were on a 22C day, I am thinking that temps is not the issue.

    Of main concern is the the way parts of the tyre have been warn down below other sections of the tyre, leaving a depression in the surface, and the fact that some of the tyre is not warn at all!...Like it never touched the surface.

    Cold tearing came to mind, but the different conditions listed above, I thought, would discount that as a possible reason.
    I was told by a regular that it is probably the traction control kicking in and out, but I switched that off, and noticed no difference apart from sliding around more

    Any thoughts?

  2. I'd imagine the new bitumen surface would play a big role. I saw a lot of photos of riders during a race event having the same issue and weren't too happy about excessive tyre wear, although they got excellent grip out of it!

    Bad batch of tyre maybe? Probably unlikely scenario.

    Regarding uneven tyre wear, maybe the tyre has bit more flex (not noticeable) at the groove causing less pressure contact between road surface and tyre? I am talking out of my arse here though...
  3. Looks like the same thing is happening on the other side of the tyre too....

    You did say this happened on the previous tyre so we can cancel out bad tyre manufacture. Has this only happened only at the track? Or just on the road or another track? I'd be sayin it's the track surface if this has happened at the one and only spot.
  4. Its the new PI surface that's doing that to your tyre, that's the end result for a Pirelli but Dunlops are getting the opposite result "polished" I think the surface will settle down soon once the cars knock it about a bit.
    Cheers B
  5. Bikes without tc getting the same wear.

    Higher pressures can help too

    From someone much smarter than me :

    "Depending on what tyre and pressure yeah! The track has so much grip it is loading the tyres alot more and in most cases distorting the shape. Think of the tyre as an un controlled spring that has to see the right mass to get the right shape to get the right grip. If its over deflected it will bounce back un controlled."

    Btw I saw same wear on same tyres used on a gsxr600
    • Like Like x 1
  6. Good find!! Should make this post a sticky in the technical section, very very helpful
  7. I have heard the new surface at PI is the grippiest surface on the MotoGP circuit. I'd say once a few cars knock the top off and lay some rubber down, it may get a little easier on tyres.
  8. According to dave moss. Your tyre is suffering from spring tear. Spring rate may be wrong. What worked before might not be okay for the surface now. But there is also a combination of worrying wear patterns on your tyre. Looks like some cold tearing too. But what is worrying is the patches of rubber between the rolled rubber that look loke they are not touched and also the scalloping in areas.
  9. Btw if your spring rate is wrong now then it is possible the tc has caused this as it unloads drive from the back tire when it senses slip. As it is very worn even now you have turned tc off the tire is probably already set in that wear pattern. Especially the low areas between ridges. New surface might need to start with high pressures again and work your way down until you find the sweet spot again
  10. #11 simidau, Mar 22, 2013
    Last edited: Mar 22, 2013
    I had the same type of wear on my Pirelli SC2 rear on my CBR250RR from the Island Classic. I would love to solve my issue as the wear rates are costing me. I'm thinking my issue could be shock spring tear.

  11. It could be the tyre. It doesn't surprise me that a Pirelli and a Metzler tyre displayed the same wear patterns, given they are very similar tyres (some models are almost indistinguishable).
  12. Maybe do some testing elsewhere,defiantly not the streer.That would be bad.Kittens and all.If the only resent variable is the new Island surface and you haven't seen it before with this rubber on your bike.Fixing it is something else.Any info available from the local suppliers or suspension gurus or racers.So what work was done in the Supers TV coverage with the resurfacing,dedicated plant on track,work done with only one but joint where they started and finished,impressive bit of civil engineering.
    • Like Like x 1
  13. #14 Roarin, Mar 22, 2013
    Last edited by a moderator: Mar 22, 2013
    I'd bet on tyre pressure. Too low. Allowing the carcase to distort too much. You can Deedee that the odd wear is running exactly parallel to the tread groove, which is a weaker part of the tyre, allowing it to flex from there.
  14. Yes mate, exactly. I can adjust for straight and consistent wear...it's these patches of nearly no tyre wear that are a concern. I also thought a spring problem, but then, as I have experienced that many times. Problem is, the extent of the wear is WAY beyond previous experience, and doesn't add up.

    Firstly, thank you for your input and advice everyone.

    I can't feel it, but it is as if the tyre is weighting, unweighting and weighting again...maybe it's tire flex(?), but then the other tyres suffered the same fate, but on a much different weather day.

    It is definitely track induced. Doesn't happen when on the road, because while i tend to run hard, I can't ride at track cornering speeds.

    And yeah, the track is so grippy, at the expense of rubber of course, that with slicks, I would consider trying for an elbow drag! :)

    Wear is ok. It's this strange wear style/pattern that is troubling.
    I do have my suspension setup for my riding, and all points are ticked off, but even then I attempted to adjust the wear style out by systematically adjusting the suspension to alter it without success.
  15. I think a combination of things. Spring rate, new surface and traction control. Might also consider a different brand tyre with harder carcass like a bridgestone r10 or dunlop gp211 dot
  16. That's usually not enough rebound damping.
  17. Weighting and unweighting of a tyre can be from the traction control. Abs has the same affect on the front end. A mate has a zx10r with abs and in videos of track riding you can see the front end diving and extending like a wave under brakes. If your tc is working hard the back will squat and lift, Squat and lift. Until the rear stops spinning. As pirellis roll out the same shed as metzelers as stated try something different the r10 are excellent on track but hard to get for that reason. Even bridgestone bt003r are an excellent track tire (not the bt003rs, different compound)
  18. Wow that's some weird shit raven!! Try emailing the photo and your story to Dave moss. He has a you tube Chanel (on the throttle) and he answers people's questions like this each week. Yours is surely interesting enough to make the cut.

    The only time I've seen curved wear like that is from TC. I could be wrong I'm used to 600s and having clean even wear. I've seen some interesting wear patterns, some people have some insane looking tears when looking in the pits but always on litrebikes which are still a bit of a black box to me.
  19. This wear is not from TC.

    LIke I said above other bikes on the island the same day, without TC I have seen exactly the same wear.