changing chainrings from 53/39 to a compact,can this be done

manimal
manimal Posts: 434
edited August 2011 in Road beginners
My bike has a 53/39 standard chainset(sram rival) which im not too keen on and want to go back to a compact the same as my old bike,can i simply change the chainrings or do i have to buy a whole new sram rival compact chainset?
If this can be done does anyone know who sells the chainrings?
Thanks!

Comments

  • rozzer32
    rozzer32 Posts: 3,897
    You would have to buy a new crankset.

    53/39 = 130 BCD
    50/34 = 110 BCD
    ***** Pro Tour Pundit Champion 2020, 2018, 2017 & 2011 *****
  • manimal
    manimal Posts: 434
    Thanks for the bad news mate, much appreciated!!
  • http://www.jejamescycles.co.uk/sram-pg1 ... 57718.html

    This is a far cheaper option and will give you ratios similar to most compact chainsets. Combining it with a compact, well then you're laughing
  • rozzer32
    rozzer32 Posts: 3,897
    But if he had a short cage rear mech then he could have to buy a new longer one to take up the chain slack.
    ***** Pro Tour Pundit Champion 2020, 2018, 2017 & 2011 *****
  • merak
    merak Posts: 323
    Assuming the top jockey wheel doesn't foul the 32 tooth sprocket which it is likely to do on a standard SRAM Rival short arm rear mech which has a maximum of 28T AFAIK
  • True, but a new rear derailleur and a £50 cassette is cheaper than switching to a compact chainset, although maths is hard :D
  • True, but a new rear derailleur and a £50 cassette is cheaper than switching to a compact chainset, although maths is hard :D
  • True, but a new rear derailleur and a £50 cassette is cheaper than switching to a compact chainset, although maths is hard :D
  • True, but a new rear derailleur and a £50 cassette is cheaper than switching to a compact chainset, although maths is hard :D
  • merak
    merak Posts: 323
    The total capacity is 31T so (53-39) + (32-11)=14+21=35T so it fails both on largest dprocket and capacity. Need to get a new cassette and rear mech (assuming short cage rear mech).
  • merak
    merak Posts: 323
    True, but a new rear derailleur and a £50 cassette is cheaper than switching to a compact chainset, although maths is hard :D
    Hmm - cassette plus med length rear mech = £50+£75 = £125
    Rival compact chainset= £114

    So, no, not really cheaper.
  • Pokerface
    Pokerface Posts: 7,960
    YOu can go compact on the big ring (you can get 130bcd chainrings in 50T) but I believe the smallest small chainring you can get in 130bcd is a 38t.

    So you can convert your existing crankset to 50/38 with new rings - but for a few extra quid, can get the correct compact you are after.
  • manimal
    manimal Posts: 434
    Thanks folks,appreciate ALL the advice but i think i will just look for a straightforward compact chainset to replace mine.
  • markos1963
    markos1963 Posts: 3,724
    Needn't cost too much if you think about it. Buy a compact chainset, sell the standard on ebay cost to you is the difference. :wink:
  • morstar
    morstar Posts: 6,190
    markos1963 wrote:
    Needn't cost too much if you think about it. Buy a compact chainset, sell the standard on ebay cost to you is the difference. :wink:

    Piffle!

    Why on earth would any sane person sell spare bike parts?

    Clearly they need to go into the collection of spare bike parts that denotes your status as a proper cyclist. Unless you've got enough bits to build multiple ramshackle uncordinated machines, you're simply not doing it right!
  • merak
    merak Posts: 323
    morstar wrote:

    Clearly they need to go into the collection of spare bike parts that denotes your status as a proper cyclist. Unless you've got enough bits to build multiple ramshackle uncordinated machines, you're simply not doing it right!
    Still can't find a use for that Suntour 5 speed freewheel...
  • markos1963
    markos1963 Posts: 3,724
    morstar wrote:
    markos1963 wrote:
    Needn't cost too much if you think about it. Buy a compact chainset, sell the standard on ebay cost to you is the difference. :wink:

    Piffle!

    Why on earth would any sane person sell spare bike parts?

    Clearly they need to go into the collection of spare bike parts that denotes your status as a proper cyclist. Unless you've got enough bits to build multiple ramshackle uncordinated machines, you're simply not doing it right!

    Ha! rumbled. I tell my missus that I'm going to sell stuff off to justify upgrades but it all ends up in the 'spares' box in the workshop to be used on a future project. :D
  • manimal
    manimal Posts: 434
    Lol!!

    Unfortunately im more of a "shoestring" cyclist hence why i asked on if i could do it on the cheap.

    does anyone know how i can tell what bb i have on my bike(kuota korsa lite) so as i can look around for another one? as i said earlier its a sram rival standard chainset but i cant see any markings on the bb.
  • rozzer32
    rozzer32 Posts: 3,897
    This will do the job

    http://www.ribblecycles.co.uk/sp/road-track-bike/Bottom-Brackets-Road-Sram-GXP-Team-Cups/SRAMBTBR220

    Not sure if they use English or Italian threads though. I'm sure someone will be along who knows.
    ***** Pro Tour Pundit Champion 2020, 2018, 2017 & 2011 *****
  • merak
    merak Posts: 323
    I'm not sure he wants a BB. He wants to know what BB spindle he has so he can buy a the right chainset - why not just buy the SRAM compact:
    http://www.wiggle.co.uk/sram-rival-blac ... e-chainset
    which fits the BB referenced by rozzer - in fact it might even be supplied with one. But I assume the SRAM Rival double that's coming off is fitted on a GXP BB and there's no need to take it out. Just swap the cranks over.
  • stevie63
    stevie63 Posts: 481
    You could even fit a Sram Apex compact crankset which is about £65 from Ribble. The only difference between it and rival is the arms are not hollow but its nearly half the price