changing chainsets

by kjonesy83   August 1, 2013  

I currently have a 50/34 chainset however I would like to change this for a 53/39... How straightforward is this to do myself?! Is there anything else i would need to change? Thanks

12 user comments

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It's fairly straight-forward. 5 minute job once you have the right tools.

a) Purchase new chain-rings - make sure they are the right "Bolt Circle Diameter" (BCD) for your crankset's spider. If you have a 50/34, your crankset almost certainly is the "compact" 110mm BCD (as opposed to the 130mm "double" standard).

b) Purchase spare chain-bolt rings. You always seem to break at least one when you change rings. I'd recommend steel, the aly are just to soft & fragile.

c) You need a good length ratcheting socket wrench, with the right size allen bolt head. You need either a flat screw-driver, or another allen wrench, to hold the other side of the chain-ring-bolt.

Process is easy, unscrew the bolts, slide the chain-rings off over the crank, slide on the new ones, torque up the chain-ring-bolts Smile. Then you need to adjust the height of your front dérailleur - loosen the actuating wire, loosen the FD clamp bolt, raise the FD, tighten the clamp & wire, adjust FD as needed.

Note, you might not find 110mm 53/39 rings - those tend to available only for 130mm BCD. But you can get 52/38 and maybe 36.

posted by Paul J [618 posts]
1st August 2013 - 14:12

3 Likes

Paul - Thanks very much for that!

posted by kjonesy83 [2 posts]
1st August 2013 - 14:25

1 Like

Paul wrote:

Note, you might not find 110mm 53/39 rings - those tend to available only for 130mm BCD. But you can get 52/38 and maybe 36.

And this is the problem!

I've been looking for 53t in 110bcd for a while, with no luck. I've only seen custom sets available at great expense..

So your only option may be to replace crankset in it's entirety

I'd be v interested to know if you find a solution though

posted by 700c [556 posts]
1st August 2013 - 14:33

1 Like

Don't forget to think about chain length. Going from a compact to a double, you might not have enough slack in the chain so a new one might be required.

posted by pirnie [184 posts]
1st August 2013 - 14:48

0 Likes

You will also need to move your front derailleur up to accommodate the extra height of the chain rings.

posted by Guido [28 posts]
1st August 2013 - 14:52

1 Like

700c wrote:
Paul wrote:

Note, you might not find 110mm 53/39 rings - those tend to available only for 130mm BCD. But you can get 52/38 and maybe 36.

And this is the problem!

I've been looking for 53t in 110bcd for a while, with no luck. I've only seen custom sets available at great expense..

So your only option may be to replace crankset in it's entirety

I'd be v interested to know if you find a solution though

'ere you go, 110BCD 53T.
http://www.spacycles.co.uk/products.php?plid=m2b0s113p1727

Fringe's picture

posted by Fringe [1081 posts]
1st August 2013 - 16:05

1 Like

Or just go for a 52 big ring for virtually no difference.

posted by racingcondor [113 posts]
1st August 2013 - 21:57

3 Likes

Or if you want to Pardy go and get some Q rings...

Sir Velo

Raleigh's picture

posted by Raleigh [1730 posts]
1st August 2013 - 22:28

1 Like

I got a Sram force double crankset for £78 on eBay , is your compact worn out?

posted by SammyG [295 posts]
2nd August 2013 - 6:22

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Fringe wrote:

'ere you go, 110BCD 53T.
http://www.spacycles.co.uk/products.php?plid=m2b0s113p1727

one note of caution, I bought a triple with those rings and TA don't seem to have spent much time changing gear. They commonly drop the chain instead of changing up.

posted by robdaykin [160 posts]
2nd August 2013 - 7:22

1 Like

robdaykin wrote:
Fringe wrote:

'ere you go, 110BCD 53T.
http://www.spacycles.co.uk/products.php?plid=m2b0s113p1727

one note of caution, I bought a triple with those rings and TA don't seem to have spent much time changing gear. They commonly drop the chain instead of changing up.

Thanks Fringe, great range of custom sizes on that site and I presume compatibility across shimano and campag.

Would be useful to get anybody else's experience? Sorry for hijacking the thread..

posted by 700c [556 posts]
2nd August 2013 - 13:09

1 Like

Is it really worth replacing the whole crankset to get 53T? I'd suggest only if your bike rides are downhill in both directions. Wink

Note that if your rear cassette has a 12T as smallest cog, then changing it to a 11T gets you a larger gear with a 52T front, than a 53T would with the 12T. I.e. 53/12 is *less* than 52/11.

posted by Paul J [618 posts]
3rd August 2013 - 12:37

2 Likes