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Recently I tried adjusting my front derailleur (Shimano 6800) so that it wouldn't rub my chain when I was in the highest gear. After playing around with the angle as well as the limiting screws, I found that the chain will clear the derailleur cage, but only when the clamp bolt starts to rub against the tire.

clamp bolt rubbing against rear tire

Is there any way to fix this without getting new tires? I've already made sure the wheels were seated properly, so I'm sure that's not the issue.

For reference, the tires I'm running are WTB Nano TCS and the bike is a Motobecane Century Pro with disk brakes.

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    From the picture, the tires look too wide, too big. The link says they are 40mm wide (40c). This frame does probably not accommodate that size, try 35, 32, 30 or maybe even 28mm tires instead.
    – Carel
    Commented Feb 3, 2016 at 19:38
  • bikesdirect.com/products/motobecane/disc-brake-roadbikes/… Website says it can fit up to 45C tires. The tires are definitely near the upper limit, but they fit on the frame just fine.
    – CopOnTheRun
    Commented Feb 3, 2016 at 19:58
  • Isn't the clearance in the photo enough?
    – mkpaa
    Commented Feb 3, 2016 at 21:34
  • Did you change the front deraileur mechanism at some point? Could be that you need an E stand not a band-on... these are the ones that go around the bottom bracket for support.
    – Criggie ♦
    Commented Feb 3, 2016 at 23:14
  • @mkpaa that's when there's still chainrub on the front derailleur, it touches the tire when there's not. @ Criggie nope, that's the stock derailleur
    – CopOnTheRun
    Commented Feb 4, 2016 at 1:19

1 Answer 1

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So after tinkering with derailleur position some more, I still couldn't get it to stop rubbing, that's when I had the bright idea to move the clamp bolt to the other side of the derailleur. Now I've got enough clearance that it doesn't rub against the tire and the chain doesn't rub against the cage. There's not a groove for the wire on the other side, but it seems to work just fine in the time I've tested it. It was a stupid idea, but I guess it works for now.

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    The risk here is that your wire will pull through or pop out under tension, dropping you back into bottom gear. Plus the angle of pull will be slightly different. However most riders set and forget the front deraileur position so its not a big deal.
    – Criggie ♦
    Commented Feb 4, 2016 at 6:10
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    Very bad idea, especially on the 11 speed Shimano designs. The clamping force required will damage the cable over time, and it will let go. The groove is there to prevent that. The 11 speed front derailleurs have a longer leverage arm than a typical front derailleur, and exert more force on the cable during a pull. In addition, that longer front derailleur is likely why you have a clearance issue. Although the frame says up to a 45c tire will fit, they don't and can't test that with all equipment installed. The frame might have clearance, but the derailleur doesn't.
    – zenbike
    Commented Jun 10, 2016 at 12:44
  • By the way, the normal front derailleur set up for 11 speed, per the factory videos, is to adjust the inside limit screw to just be touching the chain without load on the drive train, a slight rub. When tension is on the chain, it pulls tighter and straighter, and the rub goes away. Is that the rub you are talking about, or is it more severe?
    – zenbike
    Commented Jun 10, 2016 at 12:46
  • The rubbing was from the chain hitting the outside of the derailleur cage when I was in a higher gear. I could change the angle of the derailleur to fix this (it was only rubbing against the front), but doing so moved the lever arm closer to the tire, which caused the problem. As far as the cable goes, I'll take your concern into consideration. Luckily when I've got the 40C tires on I'm usually riding in the first chainring anyway, so it's not a huge deal.
    – CopOnTheRun
    Commented Jun 10, 2016 at 21:12

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