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  1. #1
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    113mm BB spindle length?

    I use the old Race Face Turbine LP cranksets. When using the Turner recommended 113mm BB spindle length, it gives me a chainline of 51.5mm. My chain rubs the outer front derailleur plate when in the outer small combo. It even rubs the outer plate when in the middle small combo. It also slightly rubs the inner plate when in the middle big combo. So, in order to not rub the outer, I need a shorter BB spindle, but then it would rub the inner plate a lot more. I am currently running a standard drive crankset with 24-36-48 rings, and have my derailleur height set accordingly. I'm swapping to the exact same crankset, but in compact drive with 22-32-44 rings, and will lower the derailleur as necessary. I'm not expecting it too, but will this decrease the rubbing? If not, what should I do? The derailleur is an XTR M961, and says it should be used with a 50mm chainline, so I could always switch to a 110mm BB spindle, but wouldn't that just rub more on the inner plate when in middle big? What's with these narrow plate derailleurs they make today? I like the old days when I could wear out the middle ring and use all eight cogs.

  2. #2
    No, that's not phonetic
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    What makes you think you can eliminate all rub? Read the little sheet that comes with every Shimano F der. It explains that certain combos rub, period. You just need to choose what gears are more important and eliminate rub in those. Ces't La Vie.
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  3. #3
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    I wish that someday they bring back non-twist shifters that had intermediate stops to allow you to trim the derailleur when you're in either middle/big or middle/small combos just like road bikes have been doing.

  4. #4
    ... I guess you won't be
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    i assume it's a race face BB, if so, then you should see if you are running the spacer [RF bb's can be run on 68 or 73mm shells by using or discarding the spacer] that allows for a 73mm bb shell - - try removing the spacer from inbetween the drive side cup an the frame to make it 68mm shell compatible....if your BB is in 73mm shell mode, then this could whack out your driveline.
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  5. #5
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    Quote Originally Posted by tscheezy
    What makes you think you can eliminate all rub? Read the little sheet that comes with every Shimano F der. It explains that certain combos rub, period. You just need to choose what gears are more important and eliminate rub in those. Ces't La Vie.
    Well, the old derailleurs didn't rub. My old XTR derailleur did not have chain rub. It was the M900 or M901. I remember it was hard to find it, and I bought the last two that the Colorado Cyclist had in their inventory. I still have one sealed in the box. This was in Jan or Feb of 1997, so I'm guessing they were 1996 or older. I think I even had shorter chainstays on my old frame, which should have made it harder for the plates to clear. I'm wondering if the difference is because the old frame used an 1 1/8" derailleur, and the Turner uses a 1 3/8" derailleur. It shouldn't matter though. That would only decrease the chainline, and make it more likely to run the inner plate, which it did not at all.

  6. #6
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    Quote Originally Posted by jokermtb
    i assume it's a race face BB, if so, then you should see if you are running the spacer [RF bb's can be run on 68 or 73mm shells by using or discarding the spacer] that allows for a 73mm bb shell - - try removing the spacer from inbetween the drive side cup an the frame to make it 68mm shell compatible....if your BB is in 73mm shell mode, then this could whack out your driveline.
    No, I'm using a non-adjustable Shimano BB. Besides, if I ran a 68/73 in 68 mode on a 73 shell, wouldn't I be missing a bit of support on the non-drive side of the BB? I honestly don't know, because I always settled for non bling and have used Shimano UN72 BB
    s.

  7. #7
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    As I was taking a shower, I realized that the non-drive cup would only stick out farther. What wouldn't work would be setting it up for 73 in a 68 shell. Still, the spindle would be off center, something you don't have to put up with when you have a spindle length choice.

    edit - I might be wrong there too, but either way, it simply doesn't make sense to have an offset spindle anyway. Not when you can choose the correct spindle length and have it perfectly centered.
    Last edited by royta; 03-19-2006 at 09:23 AM.

  8. #8
    Alaska Turner Mafia
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    Hey Royta, I'm running the same cranks/BB on three of my Turners. The only difference is in each case I have front shifters that allow you to "trim" the front drlr a mm or so in either direction to avoid any drlr cage rubbing. Even on my Pack, which doesn't have that crankset, I'm running a Suntour friction thumbshifter for that very reason.

    I've always preferred the narrower caged front drlrs anyway. You get faster response, but with that comes some rub at the outer extremes of your cassette range. Either you have to be meticulous about setting up your front shifter, like with triggers, or give yourself the trimming option by using a multi-indexed twist shifter or thumbie. I know my Pack looks odd with a RF Plus rear shifter and thumbie front, but whatever it takes to make you happy.

    Rando
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  9. #9
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    What makes me happy are my XTR M951 shifters, on both ends of the handlebars. I would much rather sacrifice a miniscule amount of front derailleur shifting speed, in order to be able to use both the large and small cogs without rubbing. Besides, chainring shifts are for the big jumps in gear inches. The majority of my shifting are on the cogs. It's pretty ridiculous that I have to choose whether or not I want the chain to rub in the middle large or outer small-second small combination. It shouldn't be rubbing in either.

  10. #10
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    Quote Originally Posted by royta
    I use the old Race Face Turbine LP cranksets. When using the Turner recommended 113mm BB spindle length, it gives me a chainline of 51.5mm. My chain rubs the outer front derailleur plate when in the outer small combo. It even rubs the outer plate when in the middle small combo. It also slightly rubs the inner plate when in the middle big combo. So, in order to not rub the outer, I need a shorter BB spindle, but then it would rub the inner plate a lot more. I am currently running a standard drive crankset with 24-36-48 rings, and have my derailleur height set accordingly. I'm swapping to the exact same crankset, but in compact drive with 22-32-44 rings, and will lower the derailleur as necessary. I'm not expecting it too, but will this decrease the rubbing? If not, what should I do? The derailleur is an XTR M961, and says it should be used with a 50mm chainline, so I could always switch to a 110mm BB spindle, but wouldn't that just rub more on the inner plate when in middle big? What's with these narrow plate derailleurs they make today? I like the old days when I could wear out the middle ring and use all eight cogs.
    I put in my first ride with the new crankset. By lowering the derailleur from the 48T height to the 44T height, the angle of the shift cable running between the derailleur and cable stop has decreased. I'm guessing this is able to move the derailleur more for every click of the shifter. There is far less rubbing of the plates, and when there is, it's not so much of a jump in gear inches when I shift the front rings. Basically, 24-36-48 has no business being used with today's front derailleurs. Where I used to ride, that gearing was fine, but here in the Santa Ana's in SoCal, the 22-32-44 is almost a necessity.

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