Advice for changing from a Uniglide cassette

[Chris C]

Hi all

I just bought a new bike and it has a Shimano 600EX 6 speed Uniglide cassette on a FH-6207 hub. The cassette is 15-22t, which at the moment, cycling in the Netherlands, is perfectly fine. Come the summer though, I'll want to be venturing out a bit further and I'm going to need a smaller gear. From the research I've done so far I have seen options and I guess I'm just after reassurances that what I think I have learned is correct and opinions on the best way to proceed.

The options I think I have are:
1) Find a different 6 speed UG cassette but this seems super expensive.
2) Use a 7 speed UG cassette on this hub and add a 1mm axle spacer to the drive side. Is this correct? I saw the same hub I have for sale and this is the advice the seller gave in the description.
3) Use a 7 speed HG cassette, filed to fit, replacing the smallest sprocket with a UG one.
4) Swap the freehub body with an HG one. Then, if I understand what I've read, I can use a 9 or 10 speed cassette with one sprocket removed. If this is correct, which freehub body would be the one to use? This would be my preferred option I think.

Cheers

Chris

 

[glpinxit]

I took the route of changing to a hyperglide freehub. Sheldon will tell you everything you need to know https://www.sheldonbrown.com/k7.html

 

[AndyMart]

Re:

I've done two of the things you mention. 7 speed cassette with the filing and 6 speed spacers, and swapped the freehub body for a 7 speed and popped a 7 speed cassette on. I'd go for the latter, you can find a 7 speed shimano hub cheaply enough on ebay and it's an easy job to swap the freehub over.

 

[Chris C]

Thanks for the replies. I've found a 7 speed hyperglide freehub body at SJS which is backwards compatible with uniglide cassettes so that seems perfect for me should I ever want to put the old UG cassette back on.

Once I've swapped the freehub body is it just a case of that the 7 speed cassette will fit or will I need to add an axle spacer on the drive side? If so will this affect the dishing of the wheel enough to matter?

Cheers

Chris

 

[AndyMart]

Re:

6 and 7 speed spacing is 126mm so no issues

 

[Jonny69]

I think you have everything under control here. Just in case:

Either use that freehub body from SJS Cycles or take the Hyperglide freehub off any of these (they should all be the same): https://www.ebay.co.uk/itm/392244522045 or https://www.ebay.co.uk/itm/273716181043 or https://www.ebay.co.uk/itm/273716022928

Conversion is simple. Take the axle out and be careful not to lose the balls. Undo the 10mm Allen key fitting which holds the freehub body on the hub and it should be a direct swap. Then you can use any 6- or 7-speed Hyperglide cassette. Or, you can use 8 gears off a 9-speed cassette, or 9 gears off a 10-speed. To do that you'll need a cassette which comes apart, or at least one where you can knock the rivets out and use the individual gear plates and spacers.

I have 9 gears off a 10-speed on mine with 10-speed indexed Dura Ace downtube shifters. It all fits in 126mm spacing with no stretching or clearance issues. Just set the derailleur screw so that it cannot overshift.

 

[Chris C]

I have 9 gears off a 10-speed on mine with 10-speed indexed Dura Ace downtube shifters. It all fits in 126mm spacing with no stretching or clearance issues. Just set the derailleur screw so that it cannot overshift.

This is what I was desperately wanting to hear! Gonna use an 11-28 cassette and remove the 11T and replace the lock ring with a 12T one. Friction shifters so no indexing concerns anyway, just happy to know it should all fit nicely.
Thanks guys for the great advice.
Chris

 

[Jonny69]

This is what I was desperately wanting to hear! Gonna use an 11-28 cassette and remove the 11T and replace the lock ring with a 12T one. Friction shifters so no indexing concerns anyway, just happy to know it should all fit nicely.
Thanks guys for the great advice.
Chris

You might find it easier to remove the biggest gear at the back. The two smallest gears near the lockring kind of nest into each other, so if you take the 11T off, the lock ring doesn't contact enough to push the cassette together properly. On mine where I took the 11T off, I rolled some 1.6mm square section steel into a ring to go into the slot in the 13T to make it all lock together. You'll see when you get the cassette. It'll be easier to pick a cassette which has a bigger largest gear than you want and take that one off. E.g. Shimano Tiagra cassettes come in 11-32 and taking off the 32 gives you 11/12/14/16/18/20/22/25/28, or taking the 34 off the 11-34 gives you 11/13/15/17/19/21/23/26/30. There's also the 11-25 and 12-28 so check the ratios.

Tiagra 10-speed cassettes come apart if you drill the ends off the 3 rivets. SRAM PG950 9-speed cassettes come apart by undoing the bolts.

 

[Chris C]

The two smallest gears near the lockring kind of nest into each other, so if you take the 11T off, the lock ring doesn't contact enough to push the cassette together properly.

The lock rings also come in a 12T version for cassettes with 12T as the smallest, I have one saved from an old cassette so finally some use for old junk! I thought about doing as you said and removing the 32T from a 11-32 but I prefer the gaps to be smaller for the higher gears as those will be used the most. I'll then have 12-13-14-15-17-19-21-24-28 if I remove the 11T from a 11-28 cassette.
Cheers for the help
Chris

 

[Jonny69]

The lock rings also come in a 12T version for cassettes with 12T as the smallest, I have one saved from an old cassette so finally some use for old junk! I thought about doing as you said and removing the 32T from a 11-32 but I prefer the gaps to be smaller for the higher gears as those will be used the most. I'll then have 12-13-14-15-17-19-21-24-28 if I remove the 11T from a 11-28 cassette.
Cheers for the help
Chris

That’s interesting, I didn’t consider that about the 12T lock cog! I might have to get an old cassette to have one of those in my stash.