Shimano 10 speed compatibility

Discussion in 'Cycling Equipment' started by JonathanUK, Mar 15, 2010.

  1. JonathanUK

    JonathanUK New Member

    Joined:
    Mar 14, 2010
    Messages:
    2
    Likes Received:
    0
    Hi all,
    I have a Shimano 10 speed triple crankset 105 series 50-39-30 knocking around - I won a shiny new Ultegra Groupset for my roadbike recently so this is surpless to requirements, the rest of the drivetrain was old and knackerd but have only just bought the crankset.

    I was thinking of using this on my 9 speed Hybrid set up with MTB drivetrain as the current 48-38-28 is too low as I mostly use this for commuting by road to work (Shimano Deore XT front Derailleur, 9 speed Deore LX shifters, 9 Speed XT Cassette, Deore XT Rear derailleur). I phoned the Shimano tech support and they told me no (as always) and as usual gave me a whole list of additional parts (amounting to a complete drivetrain) that I would need to replace basically telling me that Shimano 10 road and 9 speed MTB is not compatible or recommended full stop but it may work, when I asked for a reason, throw ratios, tolerances etc - I was told that was all proprietory info.

    Before I go and spend $30 on a new BB and spend a saturday afternoon of time trying in vain to make it work does anyone know if there is a valid reason why it won't work or whether it is just the usual Shimano sales pitch.

    Regards

    Jon
     
    Tags:


  2. dabac

    dabac Well-Known Member

    Joined:
    Sep 16, 2003
    Messages:
    2,286
    Likes Received:
    139
    A 48 being too low? Highly doubt that. Spend a lot of time above 30 MPH? Or are you another one of those accustomed to low cadences?
    Besides, going to 50T will only give you about 1 MPH more before spinning out.

    Ignoring the fact that it won't give you much, all you want to do is to stick a 10-spd 105 crankset on a 9-spd hybrid?

    Potential issues:

    Chainring/chainstay clearance, but if you have clearance for a 48 it should be easy enough to eyeball whether a 50 is likely to fit or not.

    MTB front shifters as a rule aren't compatible with road FDs but if you're keeping your FD and controls, this isn't an issue.

    In theory the wider 9-spd chain would be a less-than-ideal fit on a 10-spd crank. I haven't tried it myself, but my guess would be that it'd work.

    The other parts aren't affected by what crank you run unless you plan to throw a 10-spd chain into the mix. My guess it that the rear would be OK with that, but that maybe your front shifting might suffer a little.
     
  3. alfeng

    alfeng Well-Known Member

    Joined:
    Jul 23, 2005
    Messages:
    6,723
    Likes Received:
    126
    The short answer is 'Yes, you can put almost any Triple ROAD crank on almost any frame ... as long as you have the appropriate BB' ...

    There are only a few frames which probably won't allow clearance for the outer chainring on a Triple ... and, on those frames, the builder had to go out of his/her way to make the chainstays too wide to allow the crank arms AND a 52t chainring to clear the chainstays.
    IF you have doubts as to whether the crank arms & chainring will clear the chainstay then MEASURE the outside-to-outside width of chainstays where the pedal passes the chainstays AND the inner measurement of the crank arms (remount the non-driveside arm 180ยบ from its current position to expedite the measurement) ...

    AND, MEASURE how much wider the outer chainring on the Road Triple is than on the outer ring of the crank which is currently on your Hybrid AND calculate whether it will fit (it should).
     
  4. JonathanUK

    JonathanUK New Member

    Joined:
    Mar 14, 2010
    Messages:
    2
    Likes Received:
    0
    Thanks for the advice - I will try it this weekend
    You are quite correct it is actually a 44 triple crank on the hybrid not a 48, my mistake, all salvaged from my recked MTB. The cycle to work is long and flat with very few traffic lights so I do get up to quite high speeds
     
  5. dabac

    dabac Well-Known Member

    Joined:
    Sep 16, 2003
    Messages:
    2,286
    Likes Received:
    139
    Well, even a 44T on a nominal 28" hybrid would get you well above 30 MPH before spinning out. That's still a fairly serious cruising speed any way you cut it.
    But I can see that you wouldn't be using the granny gear much:D

    For a commuter I wouldn't bother, unless the current crankset was worn out. I run an even lower ratio on my commuter and there's maybe a 30 sec total(on a 1+ hour ride) where I'm at risk of spinning out.

    The one advantage I can see is that you could switch to a cassette with a bigger smallest sprocket, and still be able to apply power downhill. The fewer the teeth, the faster the wear, so a bigger smallest can have some advantage.
     
  6. agotangelo

    agotangelo New Member

    Joined:
    Mar 15, 2010
    Messages:
    9
    Likes Received:
    0
    I would buy a 46 teeth chainring instead of trying myself what you intend, but IF you dare:

    The main issues are the difference of size of the rings and that the chain line has to remain paralel to the frame when it is on the middle ring and the middle cog. It depends of the bottom bracket length. I don't know if any problem could arise at this point due to differences in the two frames or in the cranks design. Why do you think in changing the BB by the way:confused:.

    In the 50/39/30 the % jumps are 28 and 30 % while in a 44/32/22 they would be 37.5 and 45 %.

    I had to replace an Ultegra front derailleur for a basic mtb one. It didn't work well with my hybrid mtb crankset because their lips have different shapes; you may have have to do the inverse movement. If you try first with your mtb derailleur:

    - The tip of the big ring teeth sould be 5 mm from the outer lip of the front derailleur so you have to raise this because of the bigger ring, reinstall completely the cable and regulate the stroke adjust screws.

    - If you replace a 44 teeth ring for a 50 you do have to replace your chain for a longer one. Get a 9-speed one as the ring thickness is 2 mm in both cases.

    If you want to use the bike on monday I would start working on saturday morning just in case I had to undo the whole thing on sunday;).
     
Loading...
Loading...