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Wanting to move from a 32-20 to 32-18 setup. What will I need to do to the chain to allow the smaller cog? Any other considerations?
Thanks
 

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if you're stepping down, then you may be able to get away by just using your tensioner. If you're maxing on your your tensioner's range, then you'll need to take off a link. Can you give us more info on what bike, tensioner type etc.?
 

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Wanting to move from a 32-20 to 32-18 setup. What will I need to do to the chain to allow the smaller cog? Any other considerations?
Thanks
I didn't do anything for my set up. I just swapped the 20t for an 18t, jumped on and rode.
 

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what frame do you have? if you have a lot of room to move the axle position, you might be able to take out a link. but if you do that and decide in the near future that you want your 20t back on there, you will need to somehow add a link to your chain or put a longer chain back on.
 

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Discussion Starter #6
if you're stepping down, then you may be able to get away by just using your tensioner. If you're maxing on your your tensioner's range, then you'll need to take off a link. Can you give us more info on what bike, tensioner type etc.?[/QUOTE

Trek Marlin SS. I don't have a chain tensioner, it's just built in to the frame with sliding bolts.
Tensioner bolts are currently about halfway back on the 20T and there is some chain slap.
 

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The frame is a Trek Marlin SS. I don't have a chain tensioner, it's just built in to the frame with sliding bolts.
Tensioner bolts are currently about halfway back on the 20T and there is some chain slap.
 

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If it were me I would go with bigger ring and keep the 20 tooth cog because the system will run smoother. You could use a 35/20 because it is a very similar ratio to the 32/18. You will need to add some links or slide your wheel forward.
:skep: He'll be just fine with 32x18. Why spend extra on a chainring, lessen clearance, with virtually no benefits?
 

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Do you already have smaller cog or bigger chainring? If you don't want to deal with shortening the chain, try to fit 18t cog. If it doesn't fit I would get a bigger chainring.
 

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You could just buy another chain to suit the 18T cog. It'd be cheaper than buying a whole new chainring i'd reckon.
 

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Ahhh the pain....
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A 1 tooth change in the cog will move the axle about 1/8"...so going from 20 to 18 w/o changing anything else (chainring, chain), will move the axle back about 1/4". Obviously, if your chain is already super loose (chainslap), then it's gonna move more to properly tension it.
 
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