Possible To Update Uniglide 6 Speed Cassette On Old MTB?

[woodbine]

I have a British Eagle MTB that's over 30 years old. It's 18 speed, with 6 gears on the Shimano Uniglide cassette and 3 oval Biopace chain rings. The cassette is the type where the smaller, outer gear has a threaded hole in the middle that screws onto the hub and holds the whole cassette together.

The cassette is original and one or two gears are starting to feel a little notchy when pedalling, I'm assuming because of wear. Because Uniglide spares are unobtainable, could I replace the cassette with something more modern, preferably also 6 speed? If yes, what would I replace it with? What else would also need to be replaced, hub, wheel, derailleur?

I won't be doing the work myself, too advanced so would leave to experts. Any advice gratefully received.

 

[midlife]

Double check the hub, some where uniglide / hyperglide combined.

 

[woodbine]

Double check the hub, some where uniglide / hyperglide combined.

Thanks for your reply. Not quite sure what you mean. Are you saying UG and HG cogs were fitted together on the same hub? It's definitely a UG hub, because the smallest cog is threaded. HGs have a lock ring. All the cogs are original as I owned the bike from 3 years old so no one's added odd parts. HG would be too late for my bike.

 

[Big John]

Apparently Uniglide, as you so rightly say, are no longer available. The following link might be worth a read, taken from Sheldon Brown's website. By the sounds of it you might be able to flip any worn sprockets over to give them a new lease of life. If you don't have the tools or the inclination to do it yourself then maybe your LBS can help. I wouldn't try Halfords. Not because I don't like Halfords but they have a tendency to throw out the old and replace with new and what is often a cheap fix becomes an expensive one.

https://www.sheldonbrown.com/k7.html#:~:text=Uniglide ®,between each pair of sprockets.

 

[buzz22]

This may help, I posted it a little while ago, it worked for me.
Happy to answer any questions.

My 80's Throwback build was almost perfect except that the 13-21 uniglide cassette on the back and 42-53 front limited the grade of the hills I could enjoy it on.
View attachment 630155
In my younger years I'd take on any hill with this combination, now at 50 not so much.
They haven't made uniglide cassettes since the early 90's and if I could find one with a 28 I'd be paying $200 or so for a NOS example.
The difference between uniglide and the current hyperglide cassettes is the splines on the hub.
View attachment 630156
It's hard to spot in the photo but the uniglide's (top) splines are all the same size, the hyperglide has one spline that's a bit smaller.
View attachment 630157
In the bottom of this photo you can see where I've filed the tab flat for the smaller spline so that the hyperglide cassette fitted on the uniglide hub.
View attachment 630158
The other difference between the two types is that the uniglide uses the smallest cog to lock the cassette onto the hub.
I found an older cassette with a 12 tooth small cog so I used this with the new hyperglide cassette which is now 12-28 instead of 11- 28.
A new chain to handle the bigger cassette and job done.
End result- a bike that's more usable and still retains the beautiful Shimano 600 tricolour hubs.
View attachment 630159

View attachment 630160

 

[Tigerbiten]

Drop the wheel out and measure the distance between the dropouts.
At a guess it will be 126mm.
BUT and it's a big BUT .....I understand that a 126mm hub may be very hard to find and/or expensive.
If it's a steel frame it could be worth while having the frame cold set to take a wider hub if you cannot get a cassette to fit the original hub.

Luck ..........

 

[woodbine]

Many thanks to Big John and buzz22. I'll take a look at the info you posted, and may come back with questions.

 

[midlife]

Thanks for your reply. Not quite sure what you mean. Are you saying UG and HG cogs were fitted together on the same hub? It's definitely a UG hub, because the smallest cog is threaded. HGs have a lock ring. All the cogs are original as I owned the bike from 3 years old so no one's added odd parts. HG would be too late for my bike.

There were hubs that took both hyperglide and uniglide cogs when they were moving from one to another. Not all HG have a, lockring

 

[woodbine]

Drop the wheel out and measure the distance between the dropouts.
At a guess it will be 126mm.
BUT and it's a big BUT .....I understand that a 126mm hub may be very hard to find and/or expensive.
If it's a steel frame it could be worth while having the frame cold set to take a wider hub if you cannot get a cassette to fit the original hub.

Luck ..........

Thanks, Tigerbiten. Yes, it's 126mm spacing. I had the free hub replaced with a new, old stock (amazingly my bike shop had one gathering dust in stock) UG hub identical to the old one that had problems. It's Shimano Deore Uniglide MT-60 hub. Just in case, I bought another pair of the same hubs (front and rear) on Ebay recently (identical to one in link below) - so I have UG free hubs to last for quite a while - it's just the gears that are a problem. Would prefer to use these hubs in any conversion to more modern cassette, but if this isn't possible can you recommend other combinations of hubs and gears?

https://www.ebay.co.uk/itm/193732137503?hash=item2d1b55d21f:g:7OAAAOSwi9ZfndoB

 

[woodbine]

There were hubs that took both hyperglide and uniglide cogs when they were moving from one to another. Not all HG have a, lockring

View attachment 641375

I understand now, thanks. So if I could find a 6 speed hyperglide cassette with threaded smallest gear, this would fit on my UG hub with a bit of grinding on the wider spline on the gears?

But then I imagine finding earlier 6 speed HG cassettes with the threaded outer gear will be almost as difficult as finding 6 speed UG cassettes.

 

[fossyant]

What you need to do is buy a HG 8 speed cassette. The biger sprockets are usually held together with a hex bolt. You need to dremmel off part of the larger splined tooth on each srocket for them to fit a UG freehub. You then keep the smallest sprocket. You also re-use the 6 speed spacers. The sprockets are the same width, but the 6 speed spacer slightly wider than 8.

I do this with my Dura Ace 7400 UG freehub - just dremmel off part of the wider splined tooth.

 

[woodbine]

What you need to do is buy a HG 8 speed cassette. The biger sprockets are usually held together with a hex bolt. You need to dremmel off part of the larger splined tooth on each srocket for them to fit a UG freehub. You then keep the smallest sprocket. You also re-use the 6 speed spacers. The sprockets are the same width, but the 6 speed spacer slightly wider than 8.

I do this with my Dura Ace 7400 UG freehub - just dremmel off part of the wider splined tooth.

Thanks, that doesn't sound too difficult. As I have 6 speed cassette at present and would like to stay with 6 to work with the index/SIS shifter - should I buy the 8 speed HG? Or the 7 speed?

Present cassette is 13-32 teeth, for MTB. Would changing to HG cassette mean different numbers of teeth/ratios?

 

[fossyant]

Thanks, that doesn't sound too difficult. As I have 6 speed cassette at present and would like to stay with 6 to work with the index/SIS shifter - should I buy the 8 speed HG? Or the 7 speed?

Present cassette is 13-32 teeth, for MTB. Would changing to HG cassette mean different numbers of teeth/ratios?

Buy any cassette, but you ditch the extra sprockets and the spacers. You re-use the 6 speed spacers. You would most likely buy a 12 x 32, ditch the 12 as you retain the screw on 13, then drop another sprocket to maintain the 6 speed.

On my old MTB it's 7 speed, although running a HG cassette hub these days (had lots of wheels over the years), so I just buy 8 speed cassettes and drop one of the sprockets. You may also find some of the cheaper cassettes have some sprockets riveted together rather than a hex bolt. Again, a dremmel will soon have the protruding end of the rivet off and the sprockets can be split.

 

[woodbine]

Buy any cassette, but you ditch the extra sprockets and the spacers. You re-use the 6 speed spacers. You would most likely buy a 12 x 32, ditch the 12 as you retain the screw on 13, then drop another sprocket to maintain the 6 speed.

On my old MTB it's 7 speed, although running a HG cassette hub these days (had lots of wheels over the years), so I just buy 8 speed cassettes and drop one of the sprockets. You may also find some of the cheaper cassettes have some sprockets riveted together rather than a hex bolt. Again, a dremmel will soon have the protruding end of the rivet off and the sprockets can be split.

Thanks again for the advice. I'm guessing you normally ditch the larger 32T sprocket? In my case this would be ideal, because the largest sprocket is hardly used.

Out of interest, if you removed one of the inner sprockets would the shifting work properly? I ask, because there would then be a bigger step up or down with the chain as it shifts because one sprocket is missing.

 

[GuyBoden]

I have a 6 speed Uniglide Cassette 28T with the hub. Also, a 7 speed Unglide/Hyperglide compatible hub.

Do you know that you can take the whole Uniglide hub out with a 5mm hex and replace it with a newer 7 Speed Hyperglide, then any Hyperglide cassette will fit. This is what I did, many years ago. You would use just 6 sprockets, your original spacers, plus an extra spacer.

I think @fossyant suggestion is a good option too.

You could buy my 6 speed Uniglide Cassette, if you think that is a better option. Make me an offer.