Six speed chain/cassette?

Slow Downcp
Slow Downcp Posts: 3,041
edited March 2009 in Workshop
Having decided to finally resurrect my Raleigh Triathlon, I could do with a new chain and cassette. Problem I have is that it's six speed, and I can't find any six speed in the usual places. Anyone know where i can get one? Or can I get away with a seven speed cassette and/or chain on the original hub? I know I'd lose the indexing of the downtube shifters, but if I'm going all retro, I may as well go back to friction shifting :lol:
Carlsberg don't make cycle clothing, but if they did it would probably still not be as good as Assos

Comments

  • alfablue
    alfablue Posts: 8,497
  • Slow Downcp
    Slow Downcp Posts: 3,041
    alfablue wrote:

    Unfortunately not - it's a cassette I need, rather than a screw on freewheel.
    Carlsberg don't make cycle clothing, but if they did it would probably still not be as good as Assos
  • Slow Downcp
    Slow Downcp Posts: 3,041
    £35 :shock:

    I only want the cassette because the two I have are 12-21 or 12-23 (combined woth a 42/52 chainset) and I'm not as young (or fit) as I used to be.

    Will a 7 speed one fit or are they wider?
    Carlsberg don't make cycle clothing, but if they did it would probably still not be as good as Assos
  • rickhotrod
    rickhotrod Posts: 181
    If it's not a 6-speed freewheel, it's probably a 6-speed UniGlide cassette.

    There are some very rare 6-speed HyperGlide cassettes that need a very rare 6-speed HyperGlide compatible freehub.

    AFAIK, the 6-speed HyperGlide cassettes were only sold in low end HG30 quality to fit a low end Acera freehub. These Acera freehubs might have only been available in 135mm rear axle width to fit low end hybrids. Approximate date of manufacture 1993.
  • andrew_s
    andrew_s Posts: 2,511
    7-speed hyperglide cassettes won't fit on your uniglide freehub (assuming it's not the very rare 6-speed hyperglide version). All the splines on uniglide are the same, so there isn't a slot wide enough for the "key" wide spline on hyperglide that ensures that the different sprockets are correctly aligned to each other. Uniglide sprockets use twisted tooth tips rather than the ramps that you get on hyperglide.

    So...
    you need to find a replacement 6-speed uniglide cassette. I'd guess that a lot of the remaining ones are only 24T max.
    or
    you need to replace the freehub body with a 7-speed hyperglide one and use a 7-speed cassette with no indexing.
    or (which doesn't help with changing ratios)......

    Uniglide sprockets will fit on the freehub both ways round, so you could break the cassette apart and fit the sprockets on backwards. You can then use a new chain and wear out the other side of the sprocket teeth. This won't work for the screw-on top gearsprocket - you'll just have to hope that's not too worn.
  • Slow Downcp
    Slow Downcp Posts: 3,041
    I think it's a Uniglide - it's a 1987 Shimano 105 hub. Looks like I'm stuck with keeping the cassette I've got and just stick a new chain on.
    Carlsberg don't make cycle clothing, but if they did it would probably still not be as good as Assos
  • rickhotrod
    rickhotrod Posts: 181
    Your rear hub is likely to be 126mm wide. This means a modern 8/9 speed hub won't fit your frame, as these are 130mm wide.

    Probably best to get a 7-speed HyperGlide hub as cassettes to fit these are still easily obtainable. 7-speed road hubs are also 126mm wide.

    You can convert a 7-speed HyperGlide cassette to 6-speed by removing the outer sprocket and using the four 3.65mm spacers from your 6-speed UniGlide cassette to replace the 3.1mm spacers that the 7-speed cassette uses. You will need to make up a spacer of about 2mm to go on the freehub before the cassette sprockets are put on.

    8 sprockets from a 9-speed cassette will also fit the 7-speed freehub. These will need a 9-speed shifter as the spacing of the sprockets is narrower. (9-speed cassettes use spacers of approx 2.55mm)