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Purchasing new chainring

curiumcurium Posts: 815
edited August 2011 in Workshop
Hi

I have a 2009 Specialized Tricross Sport.

The crank is a triple 50-39-30 made by FSA

I noticed the 50 ring is quite worn. I checked on Sheldon and figure i need a 130 BCD for the middle and outer and a 74 BCD for the inner.

The middle and inner aren't so worn.

Can I just replace the outer chainring?

Does it need to be made by FSA?

I should mention that the middle and outer look to be attached by the same bolts. Does this mean I should replace them together?

Cheers!

EDIT: The shimano chainrings on CRC seem to be listed as A type, B type, C type etc. Does this mean they are not compatible with the 130 BCD type crank rings?

Posts

  • explosifpeteexplosifpete Posts: 1,327
    It is fine to just replace the one chainring and quite normal as you will use one ring more than the others. As long as it is the same BCD and thickness (you get 1/8" thick rings for singlespeed bikes) it will work fine
  • curiumcurium Posts: 815
    Cheers!

    Only problem seems to be wiggle and crc and merlin don't seem to have any 50t 130 bcd in stock and lots of other places turned up in google don't state whether it's 130 or 110 bcd. aaaargh!!!

    I'll have to fit the new chain on to the old chainrings for now and hopefully they'll get stock in soon.
  • rafletcherrafletcher Posts: 1,235
    curium wrote:
    Cheers!

    Only problem seems to be wiggle and crc and merlin don't seem to have any 50t 130 bcd in stock and lots of other places turned up in google don't state whether it's 130 or 110 bcd. aaaargh!!!

    I'll have to fit the new chain on to the old chainrings for now and hopefully they'll get stock in soon.

    Try here...

    http://www.ukbikesdepot.com/m83b80s494p ... S_GB/12785

    Spare rings are never cheap.
  • curiumcurium Posts: 815
    rafletcher wrote:
    curium wrote:
    Cheers!

    Only problem seems to be wiggle and crc and merlin don't seem to have any 50t 130 bcd in stock and lots of other places turned up in google don't state whether it's 130 or 110 bcd. aaaargh!!!

    I'll have to fit the new chain on to the old chainrings for now and hopefully they'll get stock in soon.

    Try here...

    http://www.ukbikesdepot.com/m83b80s494p ... S_GB/12785

    Spare rings are never cheap.
    Thanks for the link! :)
  • mz__jomz__jo Posts: 398
    There is a lot of choice at Spa Cycles as well. This is the link to their Stronglight offering but they also have TA rings.
    http://www.spacycles.co.uk/products.php?plid=m2b0s149p0
  • This might not be a typical example but I was having shifting problems with my FSA Omega compact crank where the chain would not move to the large ring while there was any pressure on the chain. I visited two different bike shops and both tried installing Shimano large chain rings on the crank but this did not fix the issue. I then visited another shop which had loose FSA rings and bought a new Gossamer ring which worked perfectly. I am not sure if it would have made any difference if both of the rings had been changed to Shimano but there were definately shifting issues on the bike that were fixed by the new FSA ring.

    Good luck!
  • rafletcherrafletcher Posts: 1,235
    This might not be a typical example but I was having shifting problems with my FSA Omega compact crank where the chain would not move to the large ring while there was any pressure on the chain. I visited two different bike shops and both tried installing Shimano large chain rings on the crank but this did not fix the issue. I then visited another shop which had loose FSA rings and bought a new Gossamer ring which worked perfectly. I am not sure if it would have made any difference if both of the rings had been changed to Shimano but there were definitely shifting issues on the bike that were fixed by the new FSA ring.

    Good luck!

    I would have just taken a 1/4 turn at a time out of the outer limit screw on the front mech to see if that sorted it.
  • deswellerdesweller Posts: 5,175
    It's quite unusual to wear out the big ring before the middle one. Are you sure it's worn? The teeth will be pointy and a bit shark-fin-shaped when they wear out...
    - - - - - - - - - -
    On Strava.{/url}
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