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[Closed] Transmission help needed please!!

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[#761069]

Hi ,

I have recently changed my chainset to a 9 speed (22/32/44 tooth combo) from an 8 speed (22/32/42) but left all of the other transmission unchanged from 8 speed. The problem i have is that the chain seems to be very slack on the smallest chainring and rubs against the bottom of the front derailleur cage.

I had already adjusted the height of the front derailleur so as to leave a 2mm gap between the cage and chainring tooth.

Will i need to adjust the spring tension of the rear derailleur to take up any slack in the chain when on the small chainring or will i need to take some links out of the chain?

Thanks

Phil


 
Posted : 05/08/2009 9:42 am
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Links out is best - not sure you can adjust spring tension really. Bizarre that it should do this though with exactly the same gears on the front. I thought the front mech needed to be 1mm above the big ring? May be wrong though.


 
Posted : 05/08/2009 9:50 am
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There must be something else, if the two are genuinely the same size that's impossible. Some cheap 8 speed chainsets have a 24t inner ring, although even that wouldn't usually be enough to make the chain really slack.


 
Posted : 05/08/2009 10:23 am
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That's waht i thought as it's still the same number of teeth (22).

Would there usually be a lot of slack on the small front chainring/ small rear cog combo anyway?


 
Posted : 05/08/2009 10:23 am
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Would there usually be a lot of slack on the small front chainring/ small rear cog combo anyway?

Yes


 
Posted : 05/08/2009 10:25 am
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Whoa! Yes, there's always going to be loads of slack from small to small and you shouldn't really be crossing right over like that as it stresses the chain sideways more than is nice for it. Sounds like it's prolly fine.


 
Posted : 05/08/2009 10:32 am
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Rickos,

Thanks very much - i'm really new to this :oops:so appreciate your help

So it would be enough on small /small for the chain to rub the bottom of the mech cage anyway?


 
Posted : 05/08/2009 10:36 am
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When you say slack No I dont think there should actually be slack as such, the mech should still keep a little tension even in small small, a normal long cage mech can just about take up all the slack and still run small small, and big big... Neither are ideal but it should do it for test purposes and the odd ferk up out on the trail.

Maybe the chain was always a bit long but you didnt pay much attention to it until your recent upgrade?


 
Posted : 05/08/2009 10:36 am
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Tinsy/Rickos - i think your right. I've probably never noticed it before because iv'e never used the small/small combo in the real world anyway.

Thanks for your help guys.


 
Posted : 05/08/2009 11:13 am