8 speed shifters and 9 speed cassette

[afl2]

Will a 8 speed shifter work with a 9 speed cassette??
Have did a search through forum and the first couple of pages mention nothing.
Thanks

 

[mcshroom]

No, the spacing is different.

 

[afl2]

ok Thanks for replying quickly

 

[mcshroom]

Sorry that was a bit short.

Basically you need to have the same speed cassette as the shifters. The rear derailleur OTOH is pretty agnostic as it just shifts as far as the shifters tell it to..

 

[sittingbull]

Technically no it wont, as said the spacing is different.

In practice I've seen it done without any problems as long as the indexing is accurate to the centre of the cassette, then it will only be out by a fraction on the outer cogs.

The lowest (biggest) cog was omitted on the 9 speed cassette a friend of mine used. It worked so well that I followed that rear wheel over hundreds of miles (he's quicker than me).

EDIT: According to Sheldon Brown the centre to centre cog spacing for an 8 spd Shimano cassette is 4.8mm, for 9 spd it's 4.34mm, so assuming a maximum of 4 shifts from the indexed cog to the extreme, the rear derailleur will be out by a maximum of 1.84mm.

It will work but I still wouldn't recommend it.

 

[02GF74]

Sorry that was a bit short.

Basically you need to have the same speed cassette as the shifters. The rear derailleur OTOH is pretty agnostic as it just shifts as far as the shifters tell it to..

haha you should have left it at the short reply. what you say is not strictly true. 8, 7 and some speeds below that (I am not totally sure how far down they go) have the same spacing but 9 is different. (I also believe 10 speed is narrower still - someone to confirm)

so you can run a 7 speed cassette with 8 speed shifter - the last click on the shifter will not shift anywhere but as long as the mech is trimmed correctly, will not cause any issues.

regarding chains, as this would be the next question, 8 and 9 are different width, the narrower chain will work on the cassette e.g. 10 spd chain on 9 speed cassette but not always the other way round as the wdier chain may interfere with the cogs.

 

[mcshroom]

haha you should have left it at the short reply. what you say is not strictly true. 8, 7 and some speeds below that (I am not totally sure how far down they go) have the same spacing but 9 is different. (I also believe 10 speed is narrower still - someone to confirm)

so you can run a 7 speed cassette with 8 speed shifter - the last click on the shifter will not shift anywhere but as long as the mech is trimmed correctly, will not cause any issues.

regarding chains, as this would be the next question, 8 and 9 are different width, the narrower chain will work on the cassette e.g. 10 spd chain on 9 speed cassette but not always the other way round as the wdier chain may interfere with the cogs.

I take it you missed the word 'basically' at the start.

I've run 7sp and 8sp set ups for years, mainly for the interchangeability but knowing that a 7sp cassette could work (with the right spacer) is not really very useful to the OP

 

[Nigelnaturist]

Just split the cassette and use 8sp spacers there is only 0.02mm difference in the cogs but 0.44mm difference in the spacers, then you can use what ratios you want.
in mm

 

[Das]

Dont know if its relevant but I run a 10 speed cassette on 9 speed shifters. I put a 10 speed chain on to compensate for the narrower spacing.