I have a Merida Matts 40D with a 9 speed rear. I dug out an old pair of wheels off an old bike which had a 7 speed rear. I’d like to put some commuter/slick tyres on them so I can swap the wheels over depending on the type of riding I’m doing. I’m just wondering if it’s possible to convert the rear wheel to a 9 speed cassette with a quick release? Might there be anything that would prevent me from doing this?

Unless the wheel was an 8/9/10 speed wheel with a 7spd cassette on and a spacer to fill up the gap, then no…

7spd cassette freehubs were a different width. Thankfully 8,9 and 10 speed have all been the same (just the chains got narrower).

Thanks. And I’m assuming I couldn’t get away with using the 7 speed cassette with the 9 speed derailleur?

mboy is half right – you can’t get a 9s cassette on a 7s freehub body, but you can convert the wheel by installing a 8 or 9s freehub body, you can then fit any 9s cassette on it (which is what was asked?)

Trying the 7s cassette in your 9s system – the gears won’t shift properly.

The 7-speed hub will take 8 of the 9 from a 9-sp cassette and you can chose which end to omit.

Sheldon Brown covers this in his cassette database.

You cannot mix a 7-sp cassette and 9-sp shifter as the gaps are different.

PaulD

Cheers, would that mean rebuilding the wheel or is the freehub body a separate part from the part of the hub that the spokes connect to?

Thanks Paul, I’ll take a look at the database.

A frehub body bolts on, cost ~£20.

unless it’s a screw-on cassette

I just took the cassette off and it’s a screw on freewheel type, not a freehub. Does this mean it’s definitely not possible?

i dont thing there is a 9 speed screw on. you can buy a new wheel (half decent) for £65 from CRC http://www.chainreactioncycles.com/Models.aspx?ModelID=80876

9 speed screw ons do exist. Any Trek Electric bike dealer should be able to get one for you as their FX+ electric bike uses one and Trek UK carry spares.

Even if I could get my hands on a 9 speed screw on freewheel, I assume the whole wheel assembly would be too wide to fit in my frame?

It should work out OK. The wheels are stil the same axle length.

MunroBiker is correct (doffs cap)

http://www.sjscycles.co.uk/sunrace-mfe909-9-speed-freewheel-13-32t-prod28322/

I reckon the only thing to do is give it a shot. Thanks for the help!

Imagine what knowledge could be in my head if that wasn’t in there?

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946#Shimano is all the fun you need!