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  1. #1
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    MX-Leader brake clearance problems.

    I have an almost newly built-up MX-Leader that's a 59cm, from about 1996 based on another picture I saw with the same paint. The bike's all built up with new Campy Athena 11 alloy. Tires are 25's and decent clearance on the front.

    On the back however, there is no clearance to the point that the tire rubs on the caliper. Wheel doesn't roll... Just barely but obviously it's not rideable. I played around with moving the wheel forwards and backwards in the dropouts, but as I guessed that didn't solve anything. This is the first bike I've had with adjustment screws in the dropouts, so any words of wisdom on how those should be set would be appreciated.

    I'd really like to stick with 25's rather than 23mm tires on this one. Any ideas?
    Attached Thumbnails Attached Thumbnails MX-Leader brake clearance problems.-photo1.jpg  

  2. #2
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    Bud, that is exactly the problem I had with my Waterford on the front...half of the people told me i was crazy....what tires are you running? I can't tell from the picture...SOME tires are decidedly higher profile than others....Michelin coming to mind!....Considering the way that frame is going to ride, 23's with 5 less psi may be a viable option!
    Of course I'm sure...that doesn't mean I'm right......

  3. #3
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    Good point on the Michelins - they remind me of going to the DMV and telling them how much I weigh so they can put that number on my driver's license.

    Tires are Clement Strada LGG which was a new one to me but recommended. Good and sticky, 120TPI. They don't seem 'large' for their size, closer to the (yes, Trek) 23's on my other road bike than the Conti 28's on the Gunnar. I don't have calipers and didn't try putting the wheels with the 23's on this frame, but I doubt that would do much or even enough just by looking at it...

  4. #4
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    Attached photo is of Continental GP3000 23s tires on a MX Leader.....I measure from the rim edge to the top of the tire 2cm and that's what space is left...not much.
    Attached Thumbnails Attached Thumbnails MX-Leader brake clearance problems.-merckx-23mm.jpg  
    Last edited by merckxman; 04-22-2012 at 06:40 PM. Reason: fixed 2mm to 2cm

  5. #5
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    It's not the 23 or 25 that is the issue necessarily, although a narrower rim may increase the profile of a wider tire. Too bad you don't have a caliper to measure rim to outside of rubber on this and your other bike. Try slipping one of the Treks wheels in there and see. I would think you could even throw the front in to see I would assume it was the same diameter as the rear. Out of curiosity, did he reset the spacing to 130? Wouldn't that reduce the distance some from axle to caliper?

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  6. #6
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    Quote Originally Posted by merckxman View Post
    I measure from the rim edge to the top of the tire 2mm and that's what space is left...not much.
    Thanks - I could work with that, not my choice but it would do.

    Quote Originally Posted by Touch0Gray View Post
    Out of curiosity, did he reset the spacing to 130?
    Didn't need to be set, it was 130. I know that because I put a 130 wheel I had on it to clamp the fork into the rack I have that you've seen. I might have a set of dividers here that I could use to check some measurements.

  7. #7
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    Quote Originally Posted by kykr13 View Post
    Thanks - I could work with that, not my choice but it would do.



    Didn't need to be set, it was 130. I know that because I put a 130 wheel I had on it to clamp the fork into the rack I have that you've seen. I might have a set of dividers here that I could use to check some measurements.
    dividers would work
    Of course I'm sure...that doesn't mean I'm right......

  8. #8
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    i have some 700 x 28 conti four season folding tires that actually measure at exactly 25 wide that fit no problems in my mxl. i have thrown all kinds of 25-28c tires in mine over the years, i wonder if a different rear brake might be in order?

  9. #9
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    Agreed, looking at the first pic the centrebolt of the caliper is well above the tire. Maybe a different caliper would work?

  10. #10
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    I'll speak for him, the root cause is the fact that it is a dual pivot rather than the single pivot. (he alerted me to the cause when he found out) Somehow the groupset shipped with the optional dual pivot rather than the standard single
    Of course I'm sure...that doesn't mean I'm right......

  11. #11
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    i think you are correct about the brake being the culprit, which is easy to address. I found my mxl to be very forgiving of big tires, I have run 28c diamond pattern tufo cross tires and some skinny knobby cross tubulars in addition to all sorts of big fat road tires including 25c armadillos, gatorskins and hard case tires plus the bigger pave tubulars. I use plain old dura ace brakes or whatever i have lying around.

  12. #12
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    I checked out my "newest" campy build after I got his e-mail and it does indeed have single pivot in the rear, which, frankly, I had not noticed since my other two campy builds both have dual pivot, front and rear and i guess i just assumed....
    Of course I'm sure...that doesn't mean I'm right......

  13. #13
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    Yeah, I'm going to guess there's about a 3mm difference in clearance between the single and dual pivot calipers. I'm working on getting the single pivot and that should clear it up. This is my first Campy build so the option of single or dual pivot rear calipers was a new thing to me. The Clement 25's measure right on 25mm wide...

  14. #14
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    The width of the tire is probably a non issue here, the height of the tire may be. I do know for sure that some tires have a taller profile than others (michelin for example is much "taller") Once you get the new calipers then you can determine if the tires will work. But you already know that....

    Interestingly enough, when i had the SAME issue on the front of my Waterford, NO ONE could figure it out....and told me i was crazy! So....nice piece of detective work! You solved my problem too (but I am not going single pivot on the front)
    Last edited by Touch0Gray; 04-29-2012 at 04:44 AM.
    Of course I'm sure...that doesn't mean I'm right......

  15. #15
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    Quote Originally Posted by Touch0Gray View Post
    ....and told me i was crazy!
    You don't say...

    Quote Originally Posted by Touch0Gray
    (but I am not going single pivot on the front)
    From what I can tell, Campy sells their brake calipers in sets - either single or dual pivot rear, but all are dual pivot front. Or go retro, I suppose - but dual pivot front is a very good thing IMO.

  16. #16
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    oh, I'm not messing with it now......brakes are just for slowing down and stopping anyhow......
    Of course I'm sure...that doesn't mean I'm right......

  17. #17
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    This is an issue on many many MXLs. Both of mine are so affected. Putting a 5mm spacer on the brake caliper mounting bolt can help move the caliper up and out from the tire slightly. Shimano 6600 calipers have the most clearance I can find in the rear.

    I run 25mm Conti GP4000 on my MXLs. But Contis measure small, of course.

  18. #18
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    hmmmmmm wonder if that would work on the front of my Waterford????..... off to the parts bin.....
    Of course I'm sure...that doesn't mean I'm right......

  19. #19
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    Hi guys, I know this an old thread but I'm having the same issues on my Merckx EMX-5 and Super Record rear brakes. I might try conti tires but really need more clearance on the brake set. MX-Leader brake clearance problems.-image.jpg

  20. #20
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    Quote Originally Posted by calgary_jim View Post
    Hi guys, I know this an old thread but I'm having the same issues on my Merckx EMX-5 and Super Record rear brakes. I might try conti tires but really need more clearance on the brake set. Click image for larger version. 

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    Nothing you can do about that, given it's carbon fiber. (Steel frame you could re-braze the brake bridge and re-paint.)

    I'd suggest you put a 5mm spacer on the rear of the brake bridge. This will move the brake out and up ever so slightly and will give you a bit more clearance.

    Annoying...

  21. #21
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    Is that a 25mm tire? If so you might just have to switch to 23mm.

    Although there has been a bit of a move to 25mm lately, this would not be the first road frame, old or new, to have clearance problems with 25mm tires. I wrote about clearance problems with my Supersix on 25mm tires also.

    Eventually I'd hope the frame manufacturers will start to adjust.
    There's sometimes a buggy.
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    One.

    So let's just say I'm drivin' this buggy...
    and if you fix your attitude you can ride along with me.

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