Fitting new Claris Chainset

kingofthetailwind
kingofthetailwind Posts: 575
edited January 2014 in Workshop
Hi, the 8 speed triple Prowheel Ounce chainset on my Triban is knackered after 3000 miles. The only viable replacement that I can see is Shimano's new Claris triple. This uses an Octalink BB rather than that square taper kind the Prowheel uses.

I want to change the chainset over myself as I've only one roadworthy bike at the minute and don't want to leave it into a LBS. I have a set of crank pullers, a hex wrench and a BB removal tool.

So once I have the chainset and octalink BB all I will need is an octalink BB tool? Will my crank pullers work with the new chainset? Will the chainline be affected?

Comments

  • nicklouse
    nicklouse Posts: 50,673
    if you get the correct BB for the crankset to give the chain line you want then there will be no change.

    BB tool should be the same.

    you dont need pullers to fit cranks but you will need the adaptor bit to get them off.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • kingofthetailwind
    kingofthetailwind Posts: 575
    Thanks Nick, at least that's one less new tool I'll need.

    But I'm a bit confused about BB sizes. Other threads suggest the Triban needs a 68mm shell, 115mm diameter BB but this refes to the original square taper BB in the Triban. I can't see any Octalink BBs in this diameter?
  • nicklouse
    nicklouse Posts: 50,673
    yes the shell width is 68mm the Octalink BB will need what ever length axel that give the chain line that you want.

    and Shimano have not put up anything on their website so I can not provide the info. I guess anyone in the trade should have the info.

    looks like 118mm or 126mm. dont guess ask the seller. or you could be buying twice.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • kingofthetailwind
    kingofthetailwind Posts: 575
    OK I'll give Chain Reaction a call and see if they can advise. Thanks very much Nick.
  • nicklouse
    nicklouse Posts: 50,673
    KingOfTheTailwind wrote:
    OK I'll give Chain Reaction a call and see if they can advise. Thanks very much Nick.
    first find out what chain line you have now.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • kingofthetailwind
    kingofthetailwind Posts: 575
    Seems to be 50mm.
  • Manc33
    Manc33 Posts: 2,157
    KingOfTheTailwind wrote:
    Seems to be 50mm.

    What seems 50mm?

    I took the BB out of my Triban 3 and it had rusted where the writing is. :roll:

    I know its a 68mm shell on the frame, but axle length of the BB is a mystery to me. 115mm?

    Getting a new frame soon and was going to swap the BB over, but its off a £300 bike and it shows, I think a new one is the best bet.

    Definitely going to invest in a Shimano UN55 with all metal cups. I always think BB's are dirt cheap for what they are. I dunno I just always expect such a component to cost £25 or £30 and they are always about £10 - for a decent one. Then again you can spend over £100 on a BB. :roll:
  • cycleclinic
    cycleclinic Posts: 6,865
    a 68x121mm BB is needed for the claris triple (shimano do not publish this in there documents but that what it takes). The ES-25 BB in this length is out of stock at madsion but there is the ES-51 though. A 126mm BB would give you a chainline that is too big and a 118mm BB run the risk of the middle ring being very close or just touching the chainstays.

    I stock this stuff that how I know.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.

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