Forum home Road cycling forum Workshop

Chainset upgrade options advice needed please

oscar3769oscar3769 Posts: 88
edited August 2010 in Workshop
I am just getting back into road bikes again and have my first triathlon in September, I also enjoy the recreational side of things, I am on a budget as the wife thinks it will be another fad!!! I am wondering what my options are if I want to upgrade my chainset, when I last rode competetively it was easy, two bolts and a couple of special spanners and two sets of bearings, its all changed now with lots of different types, I have a 2006/7 Giant OCR2 with a Truativ triple, I think the bottom bracket is a square tapered one but could be wrong, does anyone know whether I have to basically replace the type that is there or can it be upgraded to a different type so I can have a different chainset, I hope the above makes sense and thanks for the help.


  • John.TJohn.T Posts: 3,698
    First why do you want to upgrade? Are you looking for a double, trying to save a bit of weight, current one worn out, etc? What sort of budget do you have?
  • bill57bill57 Posts: 454
    A triple chainset on square taper means a fairly long axle; you'll not find much to fit the existing axle that is much different from what you have.

    That dealt with, you should regard this as replacing the chainset AND the bottom bracket, in which case your choice is relatively unlimited - just choose the chainset that appeals, and buy the appropriate bottom bracket.

    If you want to narrow this down, as, for example, ISIS bottom brackets have a poor reputation for longevity, then throw them out of the equation and keep going.
  • sungodsungod Posts: 16,071
    yes you can replace the bb

    to give an idea what's involved...

    you'll need the correct tools to remove the cranks and the bb, and a big spanner, the tools you need will probably be this type... ... 360031496/ ... 360041220/ are probably only going to need these tools once, so worth seeing if you can borrow them

    the ocr will have english threads on the bb shell, and it'll be 68mm wide, so once you decide what crankset, you can choose the correct bb: english, 68mm

    most cranksets will be compatible with the ocr bb shell

    imho shimano 105 6600 series is a good option to consider, this needs a hollowtech ii bb

    you'll also need the correct tool to it the new bb, will depend on the bb, for the shimano htii this one is nice as it also does the crank caps... ... 360013016/

    assuming you want to go from triple to double, you'll also need to replace the front derailleur

    if you increase the size of the big chainring then you may also need to fit a new chain to get the correct tension (so you'll need a chain tool)

    everything else will be ok (the shifter will ok with a double, just give two strokes of the lever, don't need to replace it)

    if you are happy dong the work and getting the tools (or borrowing from someone), it is not a complex job, you'll find full adjustment info supplied with shimano parts and also on their website, the park tools website also has loads of info

    the other option is get the lbs to do it, but they'll probably charge more than it'd cost you to buy the tools
    my bike - faster than god's and twice as shiny
Sign In or Register to comment.