Swapping cassette - ovelap in low gear

[upandover]

Hi,

I've just swapped wheels on my flat-bar road and cross bike, as I broke a spoke on the road, and wanted to have time to fix it. (not riding the cross far at the mo cause of my back and the greater stretching)

The new cassette has a 32 instead of 28 lowest cog, and when I change into it, the small cog on the derailleur is to close to the casette, and the cog spike as the roll the chain clack on the cassette as it goes around.

I'm happy to be wrong, but it doesn't seem to be the length of the chain, (it's not worse in the front middle ring). I don't need to use that gear, and will fix my other wheel tomorrow, but, could anyone offer any suggestions please?

Could it just be that the rear mech (Shimano Tigra) won't accommodate the range?


Thanks
Steve

 

[ianrauk]

you should be able to move the deraillieur down with a few turns of the b-screw, tighten it up and it should move the dr away from the cog

Full explaination here http://www.parktool.com/repair/readhowto.asp?id=64

 

[upandover]

Thanks - I'd forgotten there are other adjustments as well as max low and high.

Thanks
Steve

 

[TheDoctor]

Hi,

I've just swapped wheels on my flat-bar road and cross bike, as I broke a spoke on the road, and wanted to have time to fix it. (not riding the cross far at the mo cause of my back and the greater stretching)

The new cassette has a 32 instead of 28 lowest cog, and when I change into it, the small cog on the derailleur is to close to the casette, and the cog spike as the roll the chain clack on the cassette as it goes around.

I'm happy to be wrong, but it doesn't seem to be the length of the chain, (it's not worse in the front middle ring). I don't need to use that gear, and will fix my other wheel tomorrow, but, could anyone offer any suggestions please?

Could it just be that the rear mech (Shimano Tigra) won't accommodate the range?

Thanks
Steve

That's probably the problem. Tiagra is a road mech, that's only supposed to cope with a 27T big sprocket. You really need an MTB mech for a 32T sprocket.