Tire Wear? What's my suspension doing?

Discussion in 'Performance & Technical' started by steve802cc, Apr 30, 2013.

  1. steve802cc

    steve802cc Knows an apex

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    I don't think this is normal tire wear. I'm not very good with suspension, anybody have any ideas as to what's causing this kind of tire wear?

    It's on my new bike here's the details
    -2006 gsxr 1000
    -20mm piston kit in the front
    -Ohlins shock (not TTX the older style)
    -front and rear springs for my weight (240lbs) and sags set-up by a professional.
    -I'm a novice racer turning 1:25's at Grattan or 1:20.xx at Summit. This was at Gingerman on Sunday. New tire 200/55, pressure set to 22psi cold. This is after only 3 maximum 4 sessions.

    Edit::doh: it's a Michelin Power Cup "B" compound.

    Edit#2: I always use tire warmers

    Any ideas? Rebound, compression, tire pressure???

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    #1 steve802cc, Apr 30, 2013
    Last edited: May 1, 2013
  2. sammPD4075

    sammPD4075 Knows an apex

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    im no expert but 22 seems low so larger contact patch which means more wear ithink
     
  3. R6 Forever

    R6 Forever Need more Grattan

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    I run power one commercial, but did Grattan 4/20 at 22 psi on rear.
    Mine did not look like that, slow or fast I pace. All of last year.
     
  4. Derrick

    Derrick Rides with no training wheels

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    Looks pretty normal to me. Especially from a 1000.:noidea::noidea:
     
  5. j.baxter

    j.baxter Rides with no training wheels

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    are we seeing cold-tear between the edge and the center?
     
  6. VernLux

    VernLux Knows an apex

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    Looks like a bit of cold tearing, other than that, pretty normal. 22PSI (set cold of course) is absolutely a good pressure for the Power Cup rear tire. I drop Peggy's Cup down to about 21, as she is obviously much lighter weight than most of you big burly guys!
     
  7. mattinrsm

    mattinrsm Old dude

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    Steve - since you said 22 psi cold, I'm assuming you aren't running warmers. My R1 does the same thing without them. I agree with the others that you have some cold tear going on. I run warmers at 70C now and don't have the issue. I chased my suspension / geometry for a while trying to fix it, but warmers worked.

    Warmers are cheap compared to tires. Now about those Honda generators.....
     
  8. Jonny Boy

    Jonny Boy Rides with no training wheels
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    Seems to be about normal wear... Your right hand might be a little greedy :)
     
  9. sammPD4075

    sammPD4075 Knows an apex

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    lol like i said im no expert .. i run slow guy street tires so im just used to higher pressures:wtf:
     
  10. sammPD4075

    sammPD4075 Knows an apex

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    haha i meant to quote this guy /\ haha dang im bad at this forum stuff
     
  11. steve802cc

    steve802cc Knows an apex

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    Good to hear from you Matt but nope I've been using warmers for years and was using them on Sunday.

    Jonny, besides the wheelies I thought I was being fairly reserved with the throttle. It was my first time on a 1000 and first time on the new bike.
     
  12. steve802cc

    steve802cc Knows an apex

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    Also Michelin only gives cold pressures for their race tires.
    This is right from the Sport bike tire service website.

    "Tire Pressure Suggestions
    Recommended COLD inflation pressures ( suggestions only by our experience ) for ground temperatures above*59°F
    *
    Dry track:
    Front tire: The inflation COLD pressure for POWER CUP front tires on dry tracks is*30psi
    Rear tire: The recommended COLD inflation pressure for POWER CUP rear tires is*22psi
    However, for ground temperatures below 59°F, the pressure should be increased to*25psi
    If the pilot wishes to have greater tire rigidity while on-angle, the cold inflation pressure can be increased up to*28psi*max."
     
  13. mattinrsm

    mattinrsm Old dude

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    Well, the only other tip I can suggest is running the harder compound rear tires, if you're not already. They are typically more resistant to tearing and give up very little to medium compounds in terms of grip.

    I'm planning on being at Grattan on May 11th, so maybe I'll bump into you then.
     
  14. VernLux

    VernLux Knows an apex

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    Just be advised, the C compound will take just a little more time to get heat into it. vs. the B compound tires if you aren't using warmers
     
  15. Dave608

    Dave608 Let's Ride!
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    Steve I think a lot of what you are seeing is fairly normal especially since you stated it was your first time on the 1000. What you are seeing is what I have heard referred to as the "acceleration band" where you are really picking up the throttle hard so a lot more wear occurs in that portion of the tire. There may be a small amount that can be fixed through suspension but most of that wear has to do with throttle progression. What happens (and this happens to a lot of people including me at times) is you know you are on a 1000 and how easy they are to spin up so you are being especially cautious with the throttle application when on the edge of the tire and as you stand the bike up and know you have more traction you really get aggressive with the throttle. The only thing that will truly eliminate that wear is being more progressive with the throttle application where you start rolling the throttle on earlier with no big jumps in amount of throttle. Very hard to get the feel for on a 1000 and can obviously spit you on your head if you get it wrong.
     
  16. ekraft84

    ekraft84 What's an apex?

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    If tire pressures, warmers, ambient temperature, etc. are working and consistent for the day/weekend, that should remove one set of variables from the equation.

    Gingerman is generally more abrasive/harder on tires than say Grattan, so you may want to try some suspension tweaks. If your sag numbers are in the ballpark, I would start experimenting with a couple clicks of compression to the shock. Try +2, see if it's better or worse. If worse, go the other direction (I would try adding it first). You could also play with the spring - take a few turns out, see if it improves. Go the other way, see if it improves. I've been told by people smarter than me that a consistent wear pattern indicates compression or spring, where an intermittent wear pattern can often indicate rebound.

    It's a crap shoot to some extent (getting suspension advice), but try some things and keep good notes of what worked and what didn't. Mid-Ohio used to be notorious for eating tires and there was plenty of time spent there just to get tire wear squared away. Significant change in ambient temperature from one event to the next will play a role as well. Also eliminating the cause as cold tear is always beneficial.

    I'm by no means an expert and filtering suspension advice can be a daunting task. Just sharing what's worked for me in the past.

    Good luck.
     
  17. steve p

    steve p What's an apex?
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  18. eE jeremy

    eE jeremy Rides with no training wheels

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    typical squid wear patterns, try not squaring up every corner so you can wheelie out of it! lol, just kidding, the wear doesn't look bad at all to me. Like others said, maybe just a little tearing, if it were me I'd start at my tire vendor and then talk to my suspension vendor and see what they both think then take action.
     
  19. sobottka

    sobottka Rides with no training wheels

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    That tearing is no good and a sign something needs adjusted. Its difficult to tell what needs adjusted just from a pic but my gut says rebound ...assuming it wasnt weather/track related.
     
  20. kerlyb

    kerlyb Rides with no training wheels

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    ^^^Hey Robbie Bobbie Baby!!!

    I had the same issue earlier this year @Barber. We fixed it by adding 3 clicks of compression.
     

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