Tire rub on chainstay?

Discussion in 'Road Cycling' started by AyeYo, Jun 11, 2014.

  1. AyeYo

    AyeYo Member

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    I'm back from vacation and not enjoying the shitty weather - day three of on/off rain and no sun now. I didn't want that to stop me from riding, so I figured I'd do a little spin on the trainer. When I was swapping rear wheels, something caught my eye. BOTH chainstays have significant gouges in them from tire rub. I've heard of a misaligned rear triangle causing rub on one or the other, but this is both equally and quite deep. Right through the paint and through at least the top layer of carbon, I can easily feel the indent with my finger. I've never noticed this damage before and I find it hard to believe it's caused by my new wheel/tire package because I actually went down from 25mm to 23mm tires. I'm wondering if this isn't caused by the trainer and the massive amount of BB flex this bike has while clamped in. The chainstay is already a tight fit around the tire as-is, but there's still a solid 1/4" clearance. Is there a way to test if it's still rubbing or if it's old damage? Should I be taking this back to the local Felt dealer to see if there's a possible safety issue?
     
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  2. jpr95

    jpr95 Active Member

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    Does your tire spin true? Is it mounted straight?
     
  3. AyeYo

    AyeYo Member

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    Wheel true looks dead nuts (by eye at least, I don't have a stand). It's mounted straight also. Even if it was mounted crooked, I'd think it would only rub one side.
     
  4. Sarabikechic

    Sarabikechic New Member

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    How long has this tire been used? Could it have merely been unobserved all along?
     
  5. AyeYo

    AyeYo Member

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    Yes, that's exactly what I'm wondering. For all I know I might have bought the bike in that condition because it's very difficult to see with the wheel mounted. That's why I'm wondering if there's a way to check for tire rub short of me having someone stick their head down there while I romp out sprints on the trainer. I would think that if it's wheel flex (highly unlikely with 35mm deep aluminum wheels) I'd be feeling brake rub long before I'd feel chainstay rub.
     
  6. Sarabikechic

    Sarabikechic New Member

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    Bearing play could be a factor however. If you grab the tire/rim at the edge can you flex the wheel without reasonable force to make it rub? If so, you may have a bearing clearance issue somewhere.
     
  7. oldbobcat

    oldbobcat Well-Known Member

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    Does the bike have horizontal rear dropouts?
     
  8. CAMPYBOB

    CAMPYBOB Well-Known Member

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    Quote be AyeYo:
    "The chainstay is already a tight fit around the tire as-is, but there's still a solid 1/4" clearance."

    Your statement makes no sense. Either it's a tight fit or the 1/4" of clearance is large enough to park a semi truck in. In bike measurements, 1/4" of clearance from tire to chainstay is huge.

    "Is there a way to test if it's still rubbing or if it's old damage?"

    Sure. Put a piece of masking tape over the chainstay and cover the damaged area. Lay into it on the trainer like you typically do. If the tape is marked or rubbed away, you got a wimpy frame and/or a trainer that is placing undue stress on your bike.

    "Should I be taking this back to the local Felt dealer to see if there's a possible safety issue?"

    It's always a good idea to get a second or third opinion when it comes to carbon damage.


    Likely causes:
    Riding with a popped spoke and out-of-true rim.
    The frame is flimsy and flexes during hard climbing and sprinting.
    The trainer restrains the bike in a manner that place stress on the rear triangle.
     
  9. AyeYo

    AyeYo Member

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    Not sure why I didn't think of masking tape. That's a pretty easy test. My bet is on the combination of trainer and flexy frame causing the BB to rotate into the tire and bump either side. I'm still going to take it to get looked at.



    Quote:
    Originally Posted by oldbobcat .
    Does the bike have horizontal rear dropouts?


    No, they're vertical.
     
  10. CAMPYBOB

    CAMPYBOB Well-Known Member

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    Quote by AyeYo:
    "My bet is on the combination of trainer and flexy frame causing the BB to rotate into the tire and bump either side."

    I have a Ti Litespeed with chainstays polished shiny by 23 MM tires. Clearance is about 1/8" per side and the 32H-3X-14 Gauge clinchers are stout. The frame? Not so much. It was never on my rollers or trainer.
     
  11. AyeYo

    AyeYo Member

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    And you consider that normal? I've found been able to find this issue mentioned by one other person with the same bike and Felt warrantied the frame. I guess I'll just have to see what the shop says.
     
  12. CAMPYBOB

    CAMPYBOB Well-Known Member

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    Normal? No. Ti frames are often consider more flexible than other materials, all things being equal (which they rarely are). Any frame that moves enough in normal road riding to rub a tire with 1/8" of daylight between tubes and tire is just plain unworthy of being ridden. Regardless of the material used to build it. I retired the Litespeed immediately after seeing the contact.

    Some trainers do exert exceptional stresses on frames. I would test the masking tape both on the road and on the trainer. I would also, as I said earlier, have your dealer check it out and maybe get the area Felt rep to inspect the damage.
     
  13. Colnago62

    Colnago62 New Member

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    I have a bike with a heavy steel frame that lives on the trainer. Between sweat and possible other stresses, why risk an expensive frame.
     
  14. AyeYo

    AyeYo Member

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    I won't be anymore. I'll be looking for something from craiglist as a dedicated trainer bike.

    I cleaned it up a little last night and what looked/felt like large gouges turned out to be tire material ON the frame. The only damage is on the non-drive side where there's a very thin groove through the clear coat (so thin it has to be from the edge of the rim and not the tire). So that's at least some good news. I have to go buy some masking tape today and do a few test rides to see which set of wheels is the one rubbing and under what conditions.
     
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