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10 speed, 11 speed mish-mash.

TwonkularTwonkular Posts: 10
edited April 2019 in Road buying advice
Should you ever pair 10 speed front chain rings with 11 speed cassettes? If so, why would one do this?

I bought a second hand road bike a year or so ago, i love it, but now in preparation for a lengthy cycling trip I am replacing some worn out parts. This has led me to take a hard look at the group-set, as I want to replace the cassette and chain-rings before I go.

The current setup has been fine to ride, but now looking at it there are a few things I don't quite follow. Its a combination of Shimano 105 and ultegra kit:

[1] 11 speed 105 casette: https://www.merlincycles.com/shimano-105-cs-5800-road-bike-cassette-72357.html?source=PHG
[2] 11 speed ultegra mid-cage rear derailleur: https://www.alltricks.com/F-32741-derailleurs_arriere/P-64939-shimano_ultegra_6800_11_speed_rear_derailleur_medium_cage
[3] 105 front derailleur that I have not yet been able to identify.

But then it appears to have a 10 speed front ring: https://www.chainreactioncycles.com/shimano-ultegra-fc6750-10sp-compact-chainrings/rp-prod116082

Is this okay?

And if i wanted to switch my rear cassette to a ultegra R8000 11-32. Would I want a like-for-like replacement of my front ring (i,e, with another 10 speed) or should I switch to an ultegra 6800 instead?

I'm a bit confused about why the bike was put together like this in the first place, but since it has so far worked seamlessly, I assume whoever built it knew more than me.

Posts

  • bondurantbondurant Posts: 858
    I have a Campag setup on one of my bikes that evolved from 10 speed to 11 speed. I kept the 10 speed chainrings. It works fine, if not quite as well as another bike with 11 speed kit throughout. So it may have been something like this that resulted in your mish-mash.
  • TwonkularTwonkular Posts: 10
    Bondurant wrote:
    I have a Campag setup on one of my bikes that evolved from 10 speed to 11 speed. I kept the 10 speed chainrings. It works fine, if not quite as well as another bike with 11 speed kit throughout. So it may have been something like this that resulted in your mish-mash.

    That's a good theory. Thanks. I guess if I'm going to replace the chainrings anyway, I may as well continue the conversion to 11 speed.
  • super_davosuper_davo Posts: 735
    I have used a 10 speed chainset with an 11 speed drivetrain and vice versa with no issues.

    I do it because I have a compact for climbing that I don't use day to day, which happens to be 6700.. and it works.

    Basically chainsets and front mechs are less fussy than rear mechs and cassettes so you can get away with it. Obviously better to fully match but not a big issue.
  • StillGoingStillGoing Posts: 5,207
    Twonkular wrote:
    Should you ever pair 10 speed front chain rings with 11 speed cassettes? If so, why would one do this?

    I bought a second hand road bike a year or so ago, i love it, but now in preparation for a lengthy cycling trip I am replacing some worn out parts. This has led me to take a hard look at the group-set, as I want to replace the cassette and chain-rings before I go.

    The current setup has been fine to ride, but now looking at it there are a few things I don't quite follow. Its a combination of Shimano 105 and ultegra kit:

    [1] 11 speed 105 casette: https://www.merlincycles.com/shimano-105-cs-5800-road-bike-cassette-72357.html?source=PHG
    [2] 11 speed ultegra mid-cage rear derailleur: https://www.alltricks.com/F-32741-derailleurs_arriere/P-64939-shimano_ultegra_6800_11_speed_rear_derailleur_medium_cage
    [3] 105 front derailleur that I have not yet been able to identify.

    But then it appears to have a 10 speed front ring: https://www.chainreactioncycles.com/shimano-ultegra-fc6750-10sp-compact-chainrings/rp-prod116082

    Is this okay?

    And if i wanted to switch my rear cassette to a ultegra R8000 11-32. Would I want a like-for-like replacement of my front ring (i,e, with another 10 speed) or should I switch to an ultegra 6800 instead?

    I'm a bit confused about why the bike was put together like this in the first place, but since it has so far worked seamlessly, I assume whoever built it knew more than me.

    Worrying over nothing. A 10 speed crankset works perfectly well with an 11 speed cassette.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • keef66keef66 Posts: 13,123
    11 speed chain is marginally narrower externally than 10 speed. So you can't run 10 speed chain on an 11 speed cassette because it will foul the adjacent sprocket.
    However internally 10 and 11 speed chains are the same, so you can run 11 speed chain on a 10 speed chainring. An 11 speed chainset might have the rings slightly closer together, but that's really the only difference. Seen lots of 10 speed chainsets with otherwise 11 speed drivetrains
  • lesfirthlesfirth Posts: 1,286
    A 105 cassette is slightly heavier than an ultegra but cheaper. That is the only difference. New ultegra equipped bikes often use a 105 cassette to save a few quid.
  • TwonkularTwonkular Posts: 10
    keef66 wrote:
    11 speed chain is marginally narrower externally than 10 speed. So you can't run 10 speed chain on an 11 speed cassette because it will foul the adjacent sprocket.
    However internally 10 and 11 speed chains are the same, so you can run 11 speed chain on a 10 speed chainring. An 11 speed chainset might have the rings slightly closer together, but that's really the only difference. Seen lots of 10 speed chainsets with otherwise 11 speed drivetrains


    That seems to be a pretty good explanation. Thanks!
  • rafletcherrafletcher Posts: 1,235
    keef66 wrote:
    11 speed chain is marginally narrower externally than 10 speed. So you can't run 10 speed chain on an 11 speed cassette because it will foul the adjacent sprocket.
    However internally 10 and 11 speed chains are the same, so you can run 11 speed chain on a 10 speed chainring. An 11 speed chainset might have the rings slightly closer together, but that's really the only difference. Seen lots of 10 speed chainsets with otherwise 11 speed drivetrains

    I believe that 11sp chainset rings are 0.4mm closer together than 10sp rings.
  • MatthewfalleMatthewfalle Posts: 17,380
    11 speed chain runs perfect on a 10 speed chainset, however not on cassette. No need to worry about it.
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
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