Chainrings

[2ky]

I'm trying to chain the chain rings on my mountain bike and road bike as the teeth are starting to look like claws!
This is my road bike but I cant seem to find the correct chain ring:

http://www.paulscycles.co.uk/m7b0s6p5259/CUBE-PELO...

Its the outer chain ring that is worn (50 teeth I believe?), I know its not top of the range but I just want to change like for like.

Now my mountain bike (2012 Cannondale SL4 9 speed read cassette-most have 8 for some reason?) has a 44 tooth out front chain ring, I'm putting an 11-34 alivio rear cassette on it but haven't got a clue which front ring to put on?

Thanks in advance!

[ecsrobin]

On both bikes on the crane arm it should have a PCD number. This is the important number you need for any chainring.

[Justin S]

Road bike:
http://www.evanscycles.com/products/shimano/sora-3...

Mountain bike chainring is not worth the bother a new chainset is here and uses the old fashioned and heavy octalink bottom brackets. Never one of the great standards.
http://www.chainreactioncycles.com/shimano-acera-m...

Better off getting a new Deore crankset and includes the new bottom bracket for a few quid more than a crankset, let alone buying individual chainrings. Bit throw away society, but believe me, you will notice the difference in stiffness, weight and bring it up to date as well.

http://www.chainreactioncycles.com/shimano-deore-m...

Edited by Justin S on Saturday 7th February 12:20

Edited by Justin S on Saturday 7th February 12:20

[2ky]

Thanks for all your help! So if I went with the last option would I get the bottom bracket with that or use my existing one? I've never replaced a bottom bracket so will I need any specialist tools?

[Justin S]

You would need one of these to fit it
http://www.chainreactioncycles.com/cyclo-hollowtec...
But its a tool for life. You will need to remove the old cranks
http://www.chainreactioncycles.com/x-tools-crank-e...

Then the bottom bracket
http://www.chainreactioncycles.com/weldtite-shiman...

If your local to Berkshire, I have everything to fit it and sort. Save buying tools !!

[jamiebae]

I'm pretty sure that isn't the right road chainring - and if it is (and you've worn out a 30t) then you need a lesson in how to use gears, or need to MTFU substantially

[Justin S]

This will fit
http://www.sjscycles.co.uk/shimano-sora-fc-3503-13...

If its the 50 rather than the 30 !!

[Dammit]

I've never worn out a chainring, despite doing a fair number of miles.

OP - are you sure you are not associating the shifting profiles of the teeth (desirable) with wear (undesirable)?

If worn the teeth should have a very, very uniform "sharks tooth" profile too them:



This is unworn:

[2ky]

Justin S thank you for the kind offer but I'm in North Wales!

I had another look at my road bike and to be honest it's not that bad, I think that can wait for now! I might have legs like a girl but it's defintley the 50 tooth chainring that's worn, the smaller one is like new and unused!

The mountain bike one looks just like the first picture, some of the places I ride have a lot of sand which probably didn't help. I took it to the LBS for something else recently and the mechanic mentioned it's worth changing the chain more frequently as its worn the cassette etc. oh well, lesson learned!