Replacing an older cassette

[lastpubrunner]

Hi All,

One of my bikes has some Wolber Profil wheels that I rather like.

However, I could do with replacing the cassette which is 6 speed. - I'd like one which is slightly lower geared - 30T, rather than 26T.

Probably a 'daft' question, but will there be any 7 speed cassette that I could replace it with ?

What viable options are there ? Without re-building the wheel ?

(It is a cassette, not a freewheel)

 

[Qubit]

Sounds like its likely a uniglide freehub. Most 6 or 7 speed (i think the 7 should be ok)uniglide cassettes should work (if you can find one, they dont make them anymore), be careful with dura ace uniglide stuff as i think the splines on the freehub were different.

If you have indexing for 6 speed obviously it wont work with 7, only in friction mode. There are other alternatives like replacing the freehub, preferably to a 126mm 7 speed one to maintain correct wheel dish. But again, you'd have to find one. (Think they only made them briefly for 600, 105 and rx100 - they have both internal and external threads for accepting uniglide and hyperglide cassettes.

Easiest/cheapest solution might be to get a 7 speed hyperglide cassette (the cogs/sprockets are the same width as 6 speed i beleive, just the spacers are thinner) and dismantle both and use say the top 1 or 2 hyperglide sprockets to get a decent ratio cassette. To do this however you would need to file or grind off the wide spline on the sprockets you wish to fit.

This should be a suitable donor cassette ending soon!

http://cgi.ebay.co.uk/Shimano-7-Speed-C ... 2a113367dd

 

[Qubit]

Quick thought, have you considered replacing your front small chainring with something smaller than the 42t that is likely there at the moment?

 

[terryhfs]

You can't put a 7 on a 6 speed freehub alas. The 6 uses the smallest sprocket as the lock ring, 7 speed and later use a separate lockring.

 

[Qubit]

You can't put a 7 on a 6 speed freehub alas. The 6 uses the smallest sprocket as the lock ring, 7 speed and later use a separate lockring.

Eh? So does 7 speed uniglide though, ie no lockring, the smallest cog screws on the outside of the freehub.