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Replacing Truvativ Firex GXP chainrings

AnonymousAnonymous Posts: 79,667
edited July 2010 in MTB workshop & tech
Trying to work out if the Firex is just one integrated lump requiring replacement of the whole crankset, or can I replace individual rings. I thought it was just all integrated but I'm not so sure now.

What's involved with doing this and if I can replace the rings, what are my options? Ideally I want something that doesn't wear out so easily, or otherwise the same chainrings but I'm not sure what I should be looking at. There seem to be hundreds of options, but don't know if they'd fit.

I think I need the middle and/or small ring.


Alternative solution is to replace the crankset with something better. If I go this route can I just replace it with (for example) an XT crankset, given it's a different BB? Do I need to have the BB shell re-faced or something like that or will it just fit no problem? (or for that matter, do I know it's been faced in the first place?). Also, switching from Truvativ, being SRAM, to Shimano XT, is that fine if I've got an SRAM chain and rear cassette?

Posts

  • robertpbrobertpb Posts: 1,866
    I replaced the middle ring with a Middleburn and the granny with an SLX.
    Now where's that "Get Out of Crash Free Card"
  • Tank-slapperTank-slapper Posts: 968
    I replaced the inner and middle rings on mine for 26T and 36T rings and run it as a double. You need to take the cranks off the bike and there are 8 bolts holding the rings on. The outer and middle share 4 and the inner has 4.

    It is doubtful that an XT crankset will fit the GXP bottom bracket. You could check by looking at the bearing diameters and distance apart, etc., but it seems a lot of faff when a new XT set comes with the BB anyway.
  • AnonymousAnonymous Posts: 79,667
    So the rings are fairly compatible then. I don't have to get the same model/brand, just so long as it has the right bolt holes?

    As for the XT crankset, I'd be using the BB that it provides, but are there any issues in changing BBs that I should be aware of? It's this 'facing' business I'm unsure about.
  • biff55biff55 Posts: 1,404
    if your bike has an internal BB cartridge inside the the shell ,
    then assume you will need the frame facing if you want external bearings for the chainset you have chosen.
    no biggy , straight forward job at a decent LBS.
    will be doing the same thing myself for my bike next month , orded cranks etc , getting bike shop to fit.
  • daveaasmithdaveaasmith Posts: 223
    Why not replace the whole thing?!

    Merlin are doing Firex Team chainsets for a little over £50, inc BB.

    http://www.merlincycles.co.uk/mountain- ... -team.html

    Dave.
  • AnonymousAnonymous Posts: 79,667
    Was thinking if I replace the whole lot, of replacing it with something better. The Firex was just what came with the bike. It seems to have worn out over just a year so not too happy with that.

    That said, the "Team" version may be different, but then a £50 crankset vs a £100 to £150+ set which is highly regarded...
  • daveaasmithdaveaasmith Posts: 223
    Yep - if I had the fundage I'd be going for some nice XT.

    As I was also only after a couple of rings, and seemingly looking to pay £30-£40 for the priviledge, the Firex Team made sense - plus a free BB for when it's needed 8) .

    Dave.
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