Worth Swapping these Chainsets?

giblets
giblets Posts: 37
edited July 2011 in MTB workshop & tech
Hi,
hopefully the right section!
Have a Giant Trance X4 with a Shimano FC-M442 front chainset. However on my older bike which is now my 'hack' I have a Shimano Hollowtech Deore LX FC-M571. Both with octalink.
They have the same number of teeth.


Is it worth swapping these over, or being an older chainset, is there not a huge difference?

Thanks
Giant Trance X4 (2010)

Comments

  • supersonic
    supersonic Posts: 82,708
    The 571 is slightly stiffer and slightly lighter. Some of that weight difference is in the rings ie the middle and outer is alloy.
  • giblets
    giblets Posts: 37
    Thanks
    think the FC-m442 is 920g weight
    FC-m571 is 720g weight

    I've a 68/118 ES25 BB, so should be a straight swap then?

    I may get a marginal imrpovement, but nothing worth writing home about?
    Giant Trance X4 (2010)
  • supersonic
    supersonic Posts: 82,708
    Not sure about the straight swap, some of the Octalink axle sizes are odd! Have to delve into the Shimano tech archives for chainlines. One version uses a 113, another a 121.

    or just swap the rings ;-)

    Assuming they are not worn.
  • giblets
    giblets Posts: 37
    Thanks, didn't realise it was so complicated!
    Just had an online check, and it would appear that with my 118 BB, that means a 50mm chainline for both, so thats a fit (if not I will soon find out!) :)
    many thanks
    Giant Trance X4 (2010)
  • giblets
    giblets Posts: 37
    Seems I am having a few problems!

    When in the middle chain ring on the front, when I select the outer rear rings (the smaller ones), the chain appears to catch on the outer chain ring on the front (i think its catching the small pegs). This is especially when I am putting a bit of power through.

    I have double checked about the chain-line and I believe I should have no problem, any ideas? (maybe the outer ring is bent slightly?)

    FC-m442
    http://techdocs.shimano.com/media/techd ... 657937.pdf

    FC-M571
    http://techdocs.shimano.com/media/techd ... 604918.pdf
    Giant Trance X4 (2010)
  • nicklouse
    nicklouse Posts: 50,675
    it can happen often when the BB axle is not long enough. But IIRC the LX did any way.

    But you don not say which one is causing issues. Have you measured the BBs? are they the same length?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • giblets
    giblets Posts: 37
    Hi,
    I just swapped the chainset on the existing BB, which is 118mm, I never had the issue witht he originally fitted M442, itsx just since fiting the LX chainset this happened.
    Giant Trance X4 (2010)
  • anjs
    anjs Posts: 486
    try swapping the bbs aswell
  • nicklouse
    nicklouse Posts: 50,675
    giblets wrote:
    Hi,
    I just swapped the chainset on the existing BB, which is 118mm, I never had the issue witht he originally fitted M442, itsx just since fiting the LX chainset this happened.

    so what was the old BB axle length then? less than 118mm?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • giblets
    giblets Posts: 37
    Hi,
    I've not changed the BB, its the original ES25 68-118, that was with the M422.
    Other than the issue mentioned, I only had to adjust the inside screw on the derailer 1 turn to get it set up.
    thanks
    Giant Trance X4 (2010)