9 speed chain + 7 s...
 

[Closed] 9 speed chain + 7 speed bike = ?

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I have been asked by a colleague to give his 17 year old Trek 930 the once over as he's become a one car family & will need to cycle to work occasionally. I've got it in the stand and it's in suprisingly good fettle apart from a slightly wonky wheel and a knackered chain. Now I have various lengths of chain knocking about so I thought I'd be benevolent and put him a new one on but what I'm unsure of is whether a modern 9 speed chain will run ok on a 17 year old 7 speed drive setup. Has anyone done this and was it ok?

Thanks in advance

Simwit


 
Posted : 16/03/2010 8:41 pm
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Not done it but wouldn't either. 9spd has narrower gap between the plates of the chain. I assume it would probably snap under load or cause horribble chainsuck, etc.


 
Posted : 16/03/2010 8:53 pm
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I've seen it work ok but I'd be concerned about cog wear.


 
Posted : 16/03/2010 8:58 pm
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Cheers for your responses guys

Regards cog wear I've laid the new bit of chain over all the rings and it looks ok, certainly better than the old chain it's more the width I was worried about.


 
Posted : 16/03/2010 9:05 pm
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all derraileur chains are 3/32"(wide across the rollers), the difference in chain width is the thickness of the side plates.

7 speed chains are easy to get hold of and common on cheap bikes.


 
Posted : 16/03/2010 9:09 pm
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ballsofcottonwool - Member
all derraileur chains are 3/32"(wide across the rollers), the difference in chain width is the thickness of the side plates.

don't thnk so.

OP compare the lengths of the chains. What you have done won't tell you if it works.


 
Posted : 16/03/2010 9:31 pm
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Why so cynical?


 
Posted : 16/03/2010 10:05 pm
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I decided to give it a go on the grounds that I can get a new chain tomorrow if it didn't work. Have just been for a spin around the block and everything seems to be working just fine so I'm going to give the fella the choice of keeping it or fitting new when I see him in the morning.

Thanks again guys


 
Posted : 16/03/2010 10:19 pm