motorapido

A friend asked me for help changing his rear cluster. Bike is 1970s. Rear wheel was replaced with an old used wheel a few years ago of unknown vintage. It's 27 inch. Gear cluster is 6 speeds, 28 tooth low gear. I assumed it is a freewheel, but asked him to send me a pic. The pic makes me wonder if it is an early 6 speed freehub cassette and not a freewheel. Appears to require a 9-spline removal tool. I believe that my cassette removal tool is 12 very small splines. What gives? If in fact it is an oddball early cassette, will a modern cassette fit the freehub? He wants to go from a 28 tooth low gear to a 34. See attached pic. Can't see as much as I would like since the nut is on the axle, but anyway.

Bill Kapaun

It's a Shimano UniGlide FH
You use 2 chain whips to take off. Smallest cog threads on to hold the rest.

A Hyperglide cog can have the wide spline filed down to make fit.
If his RDER will handle a32T cog**********?

motorapido

Ah ha. Thanks. Now, what are the options for buying a new cassette? Is the Uniglide freehub body different than current generation Shimano? Not sure from back in the day if I remember 6 speeds with bigger than the 28 cog he has now. The original objective of the project was to get a cluster on there with larger than 28 teeth.

79pmooney

I don't recognize it but I am pretty certain that is a freewheel. (Don't know of any 5-speed cassettes.) I'm also thinking the remover will be a smaller splined unit that fits over the axle after the locknut and spacers have been removed. (That could be a fun process. ) Maybe Regina? I rode in those days but missed the Reginas.

Edit: And what do I know?

Ben

onsay99

+1 for Bill Kapaun. This is indeed an early shimano uniglide cassette. The first cog was threaded onto the
freehub body and held the rest of the cassette cogs on the freehub body instead of the hyperglide method
which used a threaded lockring to hold the cassette cogs tight. Takes two chain whips for removal.

Bill Kapaun

There are no options to buy new AFAIK. You may find individual cogs for a good price.
The GOOD NEWS is that all but the screw on cog can be reversed.
If you look at the pic I posted did you notice WIDE SPLINE?
I currently have a 13-30 6 speed Uniglide cassette (off my 87 Rockhopper), so they did come larger than 28. I don't know if they came bigger than 30 though.
The wide spline (as I already mentioned) on a Hyperglide cog and be filed away to make it fit a Uniglide hub.

IF the FH body is attached with a 10mm cassette fixing bolt, a older style Hyperglide FH hub body will bolt on.

rccardr 

Bill is correct, it’s an early freehub. Not compatible with the later style hub mounting system; these are a completely different design.
There are 32 tooth UG cogs (I sold one about a month ago) but hard to come by and expensive.
Easier, as Bill said, to buy a wide range HG cassette, choose the gears you want, file out the small slot (takes about 10 seconds with a Dremel), use the existing cog spacers, and use the existing first cog to lock it down. In a pinch, I have some new first cogs if that one is worn out.

Phil_gretz

This. Using 2-chain whips, remove the first cog and then slide the rest. Then, back out the locknut and cone nut on one side and pull the axle. You'll find out whether or not you have the earliest press-fit one (bad) or the 10 mm central bolt-on (good). Replacement freehubs are plentiful. I'm interested to find out what you discover. Good luck.

Bill Kapaun

IF it has a fixing bolt, it'll be like part #13 in the attached pdf.

Barry2 

Did you pick up on Bill's question ????

When a read derailleur moves to the largest rear cog, it has to be able to keep itself clear of that large cog. This is "Max Cog Size" and rated in Teeth.
The rear derailleur has to take up the slack in the chain from you changing gears to smaller cogs.
The ability to take up the slack is referred to as a rear derailleurs "Capacity" and is also rated in Teeth (just to confuse you & me)

You need to check these two rear derailleur ratings before you select the cog size for the rear.

Cog Size is easy to count. and the Max Cog size will be stated by the manufacturer oft the rear derailleur.
Capacity takes a little math....
Biggest front ring - Smallest front ring + Biggest Rear Cog - Smallest Rear Cog = Capacity (this Capacity number "should" not exceed the rear derailleur Max Capacity in the manufacturers spec)

As many will tell you, these specs can be conservative. If in doubt add further details to this post regarding front chainring size(s) and the derailleur in use.

All the best

Barry

70sSanO

I don't understand. I realize that these things are hit or miss and you have to get lucky, but to say they are not there is simply not really looking. You may have to get creative and you may have to spend a little but..

https://www.ebay.com/itm/New-Old-Sto...cAAOSwT9Nem22G

https://www.ebay.com/itm/Shimano-Cas...ed359c919251e6

These are just a couple, but they can be found. Now you may have to swap the rear derailleur. but I think you can get there; and make it even better if that 600 freehub fits.

John

Bill Kapaun

What question are you answering?

70sSanO

If I read it incorrectly, I apologize, but I thought some indicated that a new cassette is not available or a 34t. It definitely wasn’t directed at you, but old parts are out there.

The OP mentioned replacing the cassette and this was a link to a replacement. That freehub and cassette is a bargain I have rarely seen, it was an extremely lucky find.

The only other option is to throw the rear wheel away, or rebuild the rim on a newer freehub, maybe spread the dropouts.

John

Miele Man

There are many Uniglide cassettes or individual cogs available on Ebay. Also, it's possible, if you're handy, to combine some Uniglide body parts and Hyperglied body parts to make a body that'll fit on some Uniglide hubs and allow one to use Hyperglide cassettes including the lockring.

How To Convert Uniglide Freehub To Hyperglide Freehub

https://www.youtube.com/watch?v=oaBQHCU9TDw

Cheers

Miele Man

Btw, if you put the wheel onto the bike and shift to the biggest cog, you can use one chainwhip to unscrew that smallest cog. Saves having to buy a second chinwhip.

Cheers

70sSanO

I’ve done a couple UG/HG 7 speed freehub bodies. The tough part is that one might work with one hub but on another it won’t completely seat and leave a gap. There is Shimano Freehub Interchangeability table which is great to a point, but it wouldn't have any 5/6 speed UG to 7 speed UG/HG freehub body info.

If someone had a number of different 7 speed UG/HG freehub bodies it would be possible to test out different ones and maybe find one that works. Without some stockpile or someone with experience on the exact swap, it is too costly to do a trial and error.

I haven’t done enough to know what fits with what beyond my own experiences.

John

Jeff Wills

There is a considerable difference between "road" cassette bodies and "mountain" cassette bodies, at least among Hyperglide units. I can't tell you about Uniglide bodies but I believe the same holds true for them. (Very early Uniglide hubs had a pressed-on cassette body which didn't interchange with anything else.)

I once swapped Hyperglide bodies among different hubs to mount a 9-speed cassette on an old Deore XT hub shell. This body failed while I was touring and the only available replacement was a "road" cassette body. This put the big cog too close to the spokes, rendering the lowest gear unusable. Not fun when touring.

70sSanO

I only know what info I’ve stumbled upon or tried. Shimano only made the 7 speed UG/HG combo freehub bodies for a short time; late 80’s to early 90’s(?). It is really a pretty cool and unique beast, if you like stuff from that era.

When my DX-650 FH body went down, I tried an XT-732 but that didn’t work. But the DX-650 FH body is the same as the 105 1055 FH. At the same time I was tinkering with lock nuts and spacers to fit a 130mm DA-7700 into a 126mm frame. Just for the heck of it, I tried the XT-732 FH body on the 7700 hub and it fit perfectly. I imagine the 7700 FH fits the XT-732. I’m pretty sure it is the same as the XTR-950, and it is supposed to fit the XT-737.

I’m sure there are all sorts of combinations that I have no clue about. There may be something buried in the FH body part number, but I got nothing.

For the OP to swap a 7 speed UG/HG body someone would really have to know what works.

While slightly off topic, Loose Screws still sells the UG screw on 1st position cogs. So if you want a 13t or 14t 1st position with a HG cassette, that might be the only way to get there.

John

sjanzeir

Is your friend open to the option of just replacing that with a screw-on arrangement and slapping a $20 Megarange freewheel on there? I mean, for a bike this old, what difference would it make?

The question remains, though: does your friend's existing rear derailleur have the capacity to accommodate a 34-tooth low gear? Everything else is meaningless if it won't take this big a cog.

Miele Man

It uses a UNIGLIDE CASSETTE not a freewheel and therefore he can't put a freewheel on that hub.

Cheers

sjanzeir

"That" refers to the hub or entire wheel, which they might even be able to find used at a reasonable price.

Cheers

70sSanO

To get back to the task at hand. If I had to do this. First, I think someone wisely mentioned flipping the cassette cogs around, if it hadn’t been previously.

I don’t know the ratios 14-28(?) And I’m just guessing 14-17-20-24-28. To go to 34t (without RD considerations) either drop the 28t and make a mega (14-17-20-24-34) or swap the 14t for a threaded 16t and drop the 17t, (16-20-24-28-34). Depends on the rider.

John

sjanzeir

I'd take the easy way out:

1. OP, before you and your friend do anything else, make sure your rear derailleur can handle the oversize cog(s).

2. Find a good used wheel locally that has a screw-on hub and spin a new freewheel with the desired ratio and number of gears on it and call it a day.

If I'm not mistaken, the priority is to get the bike back on the road, rather than trying to keep it period-correct.

70sSanO

Since we have no idea the history or use of this bike, the OP’s friend has to decide. If there is a personal attachment the friend has and it has been ridden by the friend for years, that is different than a bike that has been neglected and discarded in the near future. The bike has survived a lot of years and there appears to be a lack of rust.

No reason to make it period correct, but it would tough for me to just blow off a friend and take the easy way out.

John

sjanzeir

No one said he should blow his friend off. It's not he who would be taking the easy way out; it would be the easy way out for the bike to get back on the road. But then again, as you said, the owner of the bike has to be the one to decide what the best way to get the wheels back rolling again is, easy or otherwise.