7/8/9 speed compability

Londonscottish

I've happily combined an 8 speed Shimano shifter and mech with a 7 speed cassette.

Now, though, I've bought some old Mavics the rear one of which had been fitted with a 9 speed cassette (and still has the freewheel fitted).

I've no idea about sizings/spacing of hubs/freewheels/cassettes and am wondering what are my options?

(a) Fit the 7 speed free wheel and cassette to the Mavic?

(b) Buy and fit an 8 speed free wheel and cassette?

(c) Buy and fit a 9 speed free wheel and cassette?

(of three three, option (b) would be the neatest)

Londonscottish

OK; just found this thread;

viewtopic.php?p=15229236

It suggests that to fit a 7 sp cassette to a 9 sp freewheel/free hub I might need a spacer.

OR that the two set ups will be totally incompatible.

Hmmm....

Londonscottish

Found more threads which suggest that I'll be OK fitting an 8 speed cassette to a 9 speed freehub.

In which case 11-30 or 11-28 it is then.

Lighter rims + lighter tyres + better ratios = better pub bike.

(it's not a pub bike any more, though, is it?)

(although the left over bits can go towards the next bike build - sorted)

nicklouse

You can't mix 9 with 7 and 8 as the indexing is different.

If you are using indexed shifters.

So anything in possible subject to a few rules.

Eg old 7speed hubs are narrower than 8/9/10 speed hubs.

So the later might not fit in the frame without adjusting it. Which depends on the frame.

So give the full story.

The Rookie

8,9 and 10 are the same width cassettes, to fit a seven you need to add a spacer.

You can't fit a freewheel at all, you can only fit different cassettes to the existing freehub on the wheel.

Mavic freehub a can be an oddity, some require a thin spacer to fit a normal 8,9, 10 speed cassette.

If you have 8 speed shifters, get an 8 speed cassette, they will 99% of the time work fine with a 7 speed rear mech.

Londonscottish

nicklouse wrote:

You can't mix 9 with 7 and 8 as the indexing is different.

If you are using indexed shifters.

So anything in possible subject to a few rules.

Eg old 7speed hubs are narrower than 8/9/10 speed hubs.

So the later might not fit in the frame without adjusting it. Which depends on the frame.

So give the full story.

The frame, shifters and mech is all 2005 Specialized Hardrock which originally ran a 3 x 8 setup.

The current rear wheel is off a 1993 Diamondback Ascent which ran a 3 X 7.

All Shimano, all works.

I've just found some Mavic rims with SD (?) hubs which were from a bike running 3 x 9. no idea of the groupset, allegedly originally on a Canondale.

That's it.

supersonic

A nine speed cassette will not work with your 8 speed shifters.

The 1993 wheel - cassette or freewheel installed (you mention both types)? I'm surprised it actually fits in the frame to be honest, most wheels back then had 130mm spacings.

Londonscottish

supersonic wrote:

A nine speed cassette will not work with your 8 speed shifters.

Thanks - it's not a config I'm actually trying to go for, I was just wondering if the freehub on new wheel would mandate the fitting of a nine speed rear cassette or not. Hopefully I can fit an eight speed cassette.

supersonic wrote:

The 1993 wheel - cassette or freewheel installed (you mention both types)?

Sorry; I was jumbling up terminology as I didn't actually know what the various components were called (until I looked it up right now). The cassette is a Shimano Hyperglide 7 Speed.

supersonic wrote:

I'm surprised it actually fits in the frame to be honest, most wheels back then had 130mm spacings.

It just dropped in and the gears worked straight off. All I had to do was set the stop screw on the rear mech so it wouldn't go past "2" on the (8 speed) shifter as this position now corresponds with the inner ring on the 7 speed cassette.

Londonscottish

The Rookie wrote:

8,9 and 10 are the same width cassettes, to fit a seven you need to add a spacer.

OK ta - so in theory I may be able to drop an 8 speed cassette onto the "9 speed" free hub

The Rookie wrote:

You can't fit a freewheel at all, you can only fit different cassettes to the existing freehub on the wheel.

That was me using the wrong terminology. The last time I mucked about with stuff like this would have been in the early 80's when cassettes hadn't been invented.....

The Rookie wrote:

Mavic freehub a can be an oddity, some require a thin spacer to fit a normal 8,9, 10 speed cassette.

The rims are Mavic, the hubs are "Coda DT Swiss Retro" which "take a 9 speed Shimano casette". I'm hoping the rear will also take an 8 speed cassettes.

The Rookie wrote:

If you have 8 speed shifters, get an 8 speed cassette, they will 99% of the time work fine with a 7 speed rear mech.

The shifters are 8 speed, the rear mech (I think) said it was a 7/8. I'm hoping to get an 8 speed cassette and hope, in turn, that that will drop onto the "9 speed" freehub without any issues.

The Rookie

An 8 speed cassette will fit a 9 speed freehub.

As SS has pointed out, the wheel may not fit in your frame as older frames had a narrower rear.

Londonscottish

The Rookie wrote:

An 8 speed cassette will fit a 9 speed freehub.

As SS has pointed out, the wheel may not fit in your frame as older frames had a narrower rear.

Thanks Rookie.

Will start focusing on wheel widths now.....

Although the frame is from 2005 and it was running an 8 speed cassette so hopefully it will wide enough