6 speed Uniglide to 7 speed Hyperglide?

I would appreciate advice on a build problem I have encountered.

I have a rear Shimano 600 hub (FH620 which I bought with a Shimano 6 speed cassette on it (which I think is a Uniglide). I was also given 7 cogs and told I could put those onto the body if I unscrewed the smallest cog. I have Shimano 600 indexed downtube 7 speed shifters to use with this setup.

I've tried to remove the smallest cog (using 2 chainwhips) but it just won't budge - I even hit the top of the whip with a hammer to try and free it.

So I used a 10mm allen key and have taken the whole thing off the hub.

Photos are https://plus.google.com/104066364077633 ... aS6YPUcgWC

What are my options from here?

Take it to a bike shop to remove it?

Get a 7 speed Uniglide cassette (are they still about?) OR a Hyperglide body and cassette (I understand that the Hyperglide gives more options and better availability)?

If I do this do I need to get a replacement axle and cones (as one side is in the hub I've removed)?

Is it perhaps cheaper to buy another set of wheels (with cassette removed!) that finding parts for what I have.

Thanks in advance for your help.

Had something similar earlier this year. Sprayed WD40 in between the small cog and the freewheel housing on which it sat, left for 15 mins, and using two chain whips the small cog came loose. Good luck.

I don't think that a 7-speed will fit. I remember changing the body on a 6-speed one years ago to fit 7. I think I slightly respaced the cones etc. with washers to get clearance and centralise the wheel again.

However, my memory ain't what it used to be.................... :?

Another 6-speed Uniglide user here...

I can see splines where the small sprocket goes on, so coupled with the fact that the freewheel unit had a 10mm Allen key fitting I'm happy that it's a Uniglide one and not a Hyperglide. As you probably know, the Hyperglide has a splined tool that you need to remove it and on the Uniglide the small sprocket screws on securing the cassette.

It's quite a big diameter thread and it could have been on there for quite some time so it doesn't surprise me that it won't budge. Persevere with WD40 or Plusgas. Mine has been off a couple of times, but I still need to stick the bike in a high gear with the chain on, foot pressed firmly on a pedal and give the chain whip a damn good belt. You're definitely undoing it the right direction?

Conversions: I'm fairly certain that the 6-speed is narrower than the 7-speed. The spacing between the gears is definitely different because the spacers are a different thickness on the 6- and 7-speed Uniglides, so if you have indexed gears it won't be compatible. Pretty sure the 7-speed Hyperglide is the same width as a 7-speed Uniglide and the spacings are the same for indexing. I've heard mixed reports, but I think you can swap 7-speed Uniglide cogs onto a 6-speed if you use the 6-speed spacers.

It's the mixed reports about this that have led me to nurse my 6-speed Uniglide. This stuff isn't cheap any more and it's quite a lot to splash out just to find out if it actually fits. I'd say if the bearings are still ok then do your best to get that one apart and maintain it regularly to keep it reliable. The sealed freewheel inside the hub can be problematic, but just soak it in petrol, thinners or WD40 to loosen the dried out debris inside, dry it out thoroughly and then soak it in oil to re-lubricate it. You can dismantle them but mine wasn't keen to budge when I tried and I didn't want to risk breaking it.

Thanks both

I'm sure I've read Hyperglide was more versatile than Uniglide, to the extent that Hyperglide cogs could be put on a Uniglide body and up to an 8 speed (on 126mm hub) made out of it if you kept above 11T and used the right spacer? But I've read so much it all starts to blur.........

I'll give it another go trying to free it - I'm turning (or not!) the small cog anti-clockwise.

I really want index 7 speed that works. Maybe another (Hyperglide compatible) hub will be the solution.

Good luck with your endeavours. I swapped a 6 speed uniglide freehub for a 7 speed hyperglide (on old Shim 600 hubs) recently and it worked perfectly. Bit of minor fiddling around with the cones/spacers/dustcovers etc. but nothing major. Might be easier to remove the uniglide body and sprockets with the 10mm allen bolt in the middle rather than keep struggling with the chain whips etc. I use everything from 7 to 9 speeds on the same uniglide freehub body, but with different spacers and still with the 126mm over-lock nut spacing.

Uniglide sprockets will fit onto Hyperglide freehubs but not vice-versa.

531 pro - you have done what I want to do, but don't I need to get the bearings and cone from the uniglide body, and if so how?

I need to find a Hyperglide body - will just a 7 speed one be all I need to track down?

Hello there. The bearings and cone will work with the new hyperglide freehub no problem (although you'll probably like to fit new bearings seeing as you've got it apart anyway). The only farting around you might have to do is with the axle spacers and dustcap - the dustcap on the end of a uniglide body is different to a hyperglide body. In my case I had a spare axle/cone assembly from a hyperglide hub and I was able to mix and match quite easily. Good luck - it's very doable with some minor fiddling around!

Thank you

so do I need one of these http://www.tweekscycles.com/Product.do? ... 3godoVsANA to get the cone out?

Is any 7 speed Hyperglide freehub body OK, or should I be after the higher end groupset ones?