10 spd Crank on a 9spd Bike

Discussion in 'Cycling Equipment' started by Blademun, Nov 26, 2006.

  1. Blademun

    Blademun New Member

    Joined:
    May 27, 2005
    Messages:
    137
    Likes Received:
    0
    Ok, bit of a long story here..

    To start, I have a Marin highway one that I have messed around with quite a bit. It was originally a 'urban' flat bar bike, but after tasting a road set up I switched it over to road. I also added on the Sram 10spd rival crank. This setup caused me a great deal of problems. The 105 shifter was meant for a triple and didn't like the derailler that was on there(because the F/D was meant for mountain shifters) so it was hard to shift and the crank was a double so it took alot of adjustments to get it to work at all. Worst of all, When I was running the double, I could not use the smallest 3 cogs of my cassette when on the inner ring of the crank. You could audibly here the chain rubbing against the outer ring and it would even 'catch' and start to ride up onto the big ring until the derailler knocked it back down.

    I can't say why it did that. Was this just a aspect of a double? Improper chainline for that frame?(meant for a triple?) Have to use a narrower? 10 spd chain?

    So a week ago I switched back to the bikes original flat bar setup, and put the old 105 triple back on so it would work with the shifters. Unfortunately, I had sold the 105 bottom bracket to a friend earlier so I had to pick a new one up from the LBS. The one they sold me ruined my crank. The splines on the BB were slightly thicker then what the crank was meant for, and it gouged the aluminum threads of my crank when I put the crank on. I realized this when the crank arms pretty much fell off today and I saw the damage. So I returned the BB, and hope to get my money back later. Thats a different story though. I Need a new crank, and I'm definately not buying it from my LBS because apparently they know jack shit.

    I am looking at the new 105 triple crank, they are going at a good price on ebay. However, they are the new 10 spd setup, which brings back painful memorys of my Sram Rival crank.

    So here is my primary question: With a 9 spd chain, will I be able to have as wide a access to my rear cogs on the middle ring as I did on my old 105 triple? Has anyone had experience running the new shimano 10 speed cranks on their 9 speed bikes? I reallllly like the looks of the new 105 crank and I want to believe it will work, but I don't want to go through another nightmare like I did with the Sram rival crank.
     
    Tags:


  2. gclark8

    gclark8 New Member

    Joined:
    Apr 13, 2004
    Messages:
    3,522
    Likes Received:
    3
    Save some money, buy a UN26 BB (square drive) and a Sugino Triple (9 speed) crankset, or similar.
     
  3. alfeng

    alfeng Well-Known Member

    Joined:
    Jul 23, 2005
    Messages:
    6,723
    Likes Received:
    126
    About a month ago, before I sold my 9-speed 105 triple-capable shifters, I had it mated to an 8-speed XT front derailleur + a 52/39 double FSA/ISIS crankset + 9-speed Shimano chain ...

    The ROAD crank was mounted on a 118mm ISIS BB because all of this "stuff" was mounted on an "old" aluminum hardtail (135mm rear spacing) ... so, it can't be described as an optimum combination of components ...

    It shifted great -- front & rear -- I allowed the front shifter to use THREE CLICKS to move the front derailleur between the stops instead of just two ...

    Your (future) results may vary!

    And, that allowing your shifter to work through three-clicks/indents may-or-may-not work for your front shifter/derailleur/etc., too.

    FWIW. Not to defend your LBS, but there are only two different Octalink-types, AFAIK:
    • XTR & ROAD are one type
    • LX/XT are another
    You may have botched the installation ...
     
  4. Blademun

    Blademun New Member

    Joined:
    May 27, 2005
    Messages:
    137
    Likes Received:
    0
    No, I went back and checked the splines on the bottom bracket and compared that to a different (dura ace) BB the shop had. The splines on the one they sold me were slightly thicker then the dura ace. The BB they sold me was called the ES31 I believe.
     
  5. alfeng

    alfeng Well-Known Member

    Joined:
    Jul 23, 2005
    Messages:
    6,723
    Likes Received:
    126
    ACK! Well, AFAIK, you are correct ...

    The ES31 BB which you were sold is probably an LX Octalink BB ...

    BUT, you probably were NOT able to get your crank very far onto the splines of the ES31 spindle ... which is why the crank arms fell off! So the receiving notches may NOT have been truly damaged and you MAY still be able to install your crank on a ROAD-or-XTR Octalink BB.

    BUT, the worst case scenario is that your crank arms are no longer compatible with a ROAD-or-XTR Octalink BB ...

    Not-for-nuttin', but the two spline patterns don't even look alike ... the ES splines are much longer ... heck, about 2x as long. That could/should have been a clue that your 105 triple crank might not fit.

    Also, the spindle on the Octalink ROAD TRIPLE is 118mm long ... is that the length of the spindle on the ES31?

    FYI. The length of the spindle will marked at the lower portion of the label -- something like:

    L <-- 113 --> R

    The BB you will want (presuming you have not irrevocably damaged your cranks) will pretty clearly indicate the same GROUP designation as your crank ... so, the 105 "triple" BB will probably be labeled as something like BB-5503. You can, of course, use an Ultegra/6503 or Dura Ace Octalink bottom bracket since they use the same spline pattern.​

    FWIW. I have used the shorter XTR 112.5 BB with a 6503 Ultegra triple crankset on a steel framed bike. I am using the same BB with a DA 7700 double crankset.​


    Again, apparently worth repeating, there are two types of Octalink splines:
    • XTR & ROAD are one type
    • LX/XT are another
    As you have learned, the two types are not interchangeable.
     
  6. John M

    John M New Member

    Joined:
    Jun 21, 2005
    Messages:
    1,404
    Likes Received:
    0
    Alfeng identified the problem with the BB incompatibility--two types of Shimano octalink splines.

    Your front shifting problem is the inherent incompatibility between Shimano road shifters and their MTB FDs as you discovered.

    As far as the chainline problems go, the rubbing of the chain on the outer chainring when on the inner is a common problem with 10s set-ups. It is very common to rub when on the smallest cogs and sometimes present on the second smallest with some frames in which the chainstays are short. A 10s chain does help but does not completely eliminate the issue. I suspect that your problem may be exacerbated by the probably 135mm rear hub as would be standard for an MTB/hybrid setup. That would put the cassette a little farther out relative to the BB than a 130mm rear hub. It would work with a triple because the outer chainrings are farther out wiht a triple and also with the longer BB used with triples but maybe not so good with a double. In the old days this could have been solved with a slightly longer BB spindle, but that adjustability is not present with the newer integrated BB systems.

    A 10s triple set-up should work ok for you with the properly matched BB and a road FD.
     
  7. Blademun

    Blademun New Member

    Joined:
    May 27, 2005
    Messages:
    137
    Likes Received:
    0
    Thanks John M and Alfeng!

    I hate to say this, but when I was installing the BB my assumption was "Octalink is Octalink". I saw the longer splines but thought that was the way it should be. As far as the 105, the splines gouged there way in about 5mm, and you can see a 'mushrooming' of metal where the gouge stops. I imagine with alot of brute force you could make it go on to the spindle all the way. I'm not going to try it though.

    Also, I won't be getting the 105 afterall, I snagged a Truvativ elita + Isis BB for 30$ on ebay. Money is tight around these times and I am very thankfull to save 30$. I've got other bills to pay afterall. LoL.

    I'd like to thank John M again. I've been wanting to hear a experienced voice clear up all the mysterys around 10 speed cranks and my shifting issues. The front derailler is from shimano's flat bar road bike group, which I believe makes them incompatible with regular road shifters. :/ I'm also glad the problem I had with my double is common, don't feel so bad about it now. At the LBS we also think that the frames geometry was meant more for a triple.
     
  8. alfeng

    alfeng Well-Known Member

    Joined:
    Jul 23, 2005
    Messages:
    6,723
    Likes Received:
    126
    Let me rephrase -- you don't need a triple crankset to use a BB that is intended for a triple ...

    As I obtusely implied by noting that I used a 118mm ISIS bottom bracket with a ROAD double (52/39) in a frame with 135mm rear spacing, my selection of a bottom bracket spindle length intended for a triple (which you already know can work well in your frame) was, in part, to adjust the chainline -- so, just as the cassette in a frame with 135mm rear spacing is ~2.5mm further away from the centerline of the bike than it would be in a frame with 130mm rear spacing, the longer spindle moves the crank ~2.5mm further away from the bike's centerline when compared to a ROAD bike whose frame has 130mm rear spacing.

    So, if the BB that you are getting with your ISIS crank only has a 113mm spindle, you may want to conisder getting an ISIS bottom bracket with a 118mm spindle at some point in the future.
     
Loading...
Loading...