SRAM S975 Quarq PM to replace Ultegra/Hollowtech II set-up

chris7
chris7 Posts: 49
edited March 2011 in Workshop
I'm considering getting an SRAM S975 Quarq Saturn power meter and I've got a few compatibility questions to which I'd appreciate anyone's input.

My bike is a 2010 Trek Madone 4.7 which has an Ultegra 6700 groupset and a Hollowtech II BB.

Is it 'simply' a case of removing the current cranks/BB and replacing with a GXP BB and SRAM S975 cranks?

If it is possible what tools would be needed? Guessing at least a Hollowtech II BB tool? Are there any similar tools required to fit a GXP BB? Are any other specialist tools required to remove/fit the cranks?

As I'm changing the front chain rings do I need to change the chain/cassette at the same time? Or is it advisable to change at the same time?
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http://blog.chrisbarber.co.uk

Comments

  • sungod
    sungod Posts: 16,853
    gxp uses the same tool as hollowtech ii

    unless they are badly worn you don't need to change chain/cassette, but if the new chainset is a 53 instead of 50 you may need a new chain (depends if the old one was too long, or was the correct length)

    to remove the cranks you should use a shimano tl-fc16 tool - screwdriver and hammer will do it, but it meses up the lockring :-)

    gxp cranks just need an 8mm hex key to install...

    http://www.sram.com/_media/techdocs/95- ... nksets.pdf
    my bike - faster than god's and twice as shiny
  • hopper1
    hopper1 Posts: 4,389
    +1.
    Only the Hollowtech BB tool needed when I did this same change.

    Note: If your BB is 68mm, you don't need to use the spacers with the GXP BB. Instructions are a bit hazey on that!
    Start with a budget, finish with a mortgage!
  • chris7
    chris7 Posts: 49
    Thanks for the replies. Hopefully it turns out to be as easy as it sounds!
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    http://blog.chrisbarber.co.uk
  • sungod
    sungod Posts: 16,853
    when you've got the old bb out, give the inside of the shell a really good clean, including the threads

    put some anti-seize compound on the threads when you fit the new bb (sometimes the new bb already has some on the threads, no harm adding a bit if they've been stingy with it though)

    makes life easier next time
    my bike - faster than god's and twice as shiny
  • chris7
    chris7 Posts: 49
    Thanks for the tips. I now need to spend some time on google to find out where has got them in stock at the best price.
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    http://blog.chrisbarber.co.uk
  • hopper1
    hopper1 Posts: 4,389
    Bought mine at Fudges... Highly rated service and price.
    Start with a budget, finish with a mortgage!
  • joeyhalloran
    joeyhalloran Posts: 1,080
    I have recently done just this, replace two of my bikes with GXP BB and swap the Quarq between them. As said all you need is a 5 and 8mm hex key and the bb removal tool, although a torque wrench is handy as they give values i don't think its 100% necessary.

    I got my Quarq from Bob Tobin at (http://www.cyclepowermeters.com/) and have received excellent service!
  • chris7
    chris7 Posts: 49
    Tried CyclePowerMeters first as that's where I got my PowerTap but they've got no stock and it'll be two weeks for delivery. Fudges have stock so placed the order with them and it should be here tomorrow / Thursday
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    http://blog.chrisbarber.co.uk