pstock

I am trying to revitalize a nice old 8-speed Dura Aced-hubbed wheel. It somehow became separated from its 8-speed Uniglide cassette.
I finally found one on ebay from Hungary but on arrival there were two problems.
1) the small threaded locking sprocket was too big. The seller has found a replacement and is sending it to me.

2.) more odd, I can only seem to fit 6 cogs and spacers (marked "8S 3.0mm" which appears to be the correct width spacer for DA.) before the last threaded locking sprocket. Which would add to 7 speeds.

Can anyone explain why I cannot get a 7th sprocket on?
if the spacers are correct, does that mean the sprockets themselves are too wide and are therefore not DURA ACE? (Possible given the final threaded locking cog is not DA.)

Peter

nwbikeman

Possibly the wrong freehub as there were 6,7 and 8 speed freehub bodies.

mechBgon

Perhaps it has a 7-speed freehub body on an 8sp hubshell. In the bigger picture, since you evidently don't mind the obsolescence factor in the first place, you could just run it as 7-speed.

FastJake

Sounds like a 7 speed Freehub body. Those old DA hubs are very incompatible with everything else, so good luck finding a Freehub body that will fit.

As you found out, you also need a special last-position cog to thread on. DA hubs used smaller threading to permit the use of an 11T cog.

Bianchigirll 

is the hub marked as an 8spd? alot of the earlier stuff actually had intigrated 8 printed on it

pstock

the hub is marked "Dura Ace" and "8 SIS"

Jeff Wills

3.0mm spacers are correct for an 8-speed system.

The 7th cog might have a built-in spacer, which would engage the splines while the actual cog part sits proud of the splines. Given that the cassette was cobbled together, it's possible the seller didn't know this.
Take a look at this (partial) cassette: https://cgi.ebay.com/Dura-Ace-8-speed...-/120734190474 . You'll see that the last splined cog has a built-in spacer. This cog would also not need an additional spacer underneath it (which is the case with some other Uniglide cassettes.

Here's another: https://cgi.ebay.com/Shimano-Dura-Ace...-/220798052510

This picture should give a better idea of what it should look like:

Kimmo 

If the cassette body is removable, I'd swap it for a HG one FTW.

pstock

"The 7th cog might have a built-in spacer,"

actually the 8th cog, the threaded one has a built in spacer.
But even then, the 7th cog doesn't hit the splines.
Stacked up the 7 unthreaded cogs measure 13mm total.


I don't know. I am surprised there is no model number marked on the body (or whatever that splined tube part is called.) I've rarely seen a shimano bit without a model number on it.

Any tips then on how I remove that body?
Once the axle is removed and the bearings exposed, it appears that circular face plate has to come off. it is marked "<Open>") but the I don't see where to attack it with a key or an allen key? there are two small indents on the face, similar to the holes on a adjustable BB cup locking ring, but they seem far too shallow to get any purchase to "unlock" it.

(I'll post a pic once I get back to a computer with the correct card reader, which I don't have here.)

pstock

OK, I was wrong.
I CAN just get purchase on that locking ring.
But turning it CCW (in the direction of the "<Open") it just spins and spins. it doesn't seem to unthread.
should it unthread and come out? or am I missing something (like I should move it to a certain position and then pull or pry it out?)

miamijim

'Open' is inreference to the dust caps which can be 'opened; to allow oiling of the bearings.

Does your hub 'step' down to where its threaded? Does it have full length splines?

https://www.bikeforums.net/showthread...highlight=dura

mechBgon

You need a special tool, the SH-TL-FH10. I like Kimmo's suggestion of replacing the freehub body with the Hyperglide model, so you're not stuck grubbing for obsolete non-HG cassettes. Or at that rate, just get a nice modern Tiagra hub for $40.

pstock

the splines on this unit are NOT full length. They end where the threading starts.

it also has a mushroom locknut.

so, per your other (excellent) thread, this is apparently an 8-speed Uniglide FH-7402?

if so then do you have any clue why would these uniglide cogs and spacers not fit?

mechBgon

Perhaps someone put the shorter cassette body on the 8sp hubshell. Can you measure the effective width of the cassette body, meaning the width of its actual cassette space?

Jeff Wills

The "Open<>Close" part is for the oil hole. It has nothing to do with retaining the cassette or cassette body. You need to remove the axle by undoing the left-side locknut and cone. Once the axle is out, you should be able to stick a 10mm hex (Allen) wrench inside and remove the body. I'm 90% certain that the 8-speed Dura-Ace cassette body is interchangeable with a Hyperglide body.

Good reference: https://sheldonbrown.com/k7.html#transplant

pstock

The splines measure 28mm to the threaded bit.
that excludes the about 2mm built-in spacer at the very inner part of the body. (so the space between the spokes and the first cog.)

mechBgon

This hub would use the exception to the rule. They look like this, with a cool spiral-y tube instead of the usual hollow 10mm hex bolt. And they require the tool I mentioned earlier.



pstock, I'll look around at work tomorrow and see if I can find any to measure as a reference. But the most logical explaination for there not being enough room for 8-speed, is that the cassette body is not the original.

Jeff Wills

And that would make it impossible to replace it with a Hyperglide body. Darn it.

miamijim

It can be converted with a Dura Ace freehub body from a 7403 hub.

mechBgon

edit: yeah, what miamijim said.

There was a HG version of these funky spiral-tube bodies, like Kimmo recommended, so technically it could be done if a guy could find one. I don't think they'll work with an 11-tooth cog, but at least 8-speed HG cassettes are still in production, so it would have somewhat of a future.

miamijim

Ok, so I re-read the original post.

The cassette you bought off eBay didn't fit because dura ace hubs use a smaller diameter threaded cog. Iirc 7th and 8th with the DA cassette both have built in spacers. It sounds like your 7th cog isn't fitting correctly.

Kimmo 

If you can't find a Dura Ace freehub body from a 7403 hub, you could disassemble the cassette body and replace the shell, but I think you'd need to remove some metal from the base of the shell where it sits in a recess in the hub flange.

mechBgon

I looked around and found an 8sp Uniglide-only body. It's got 35mm of cog space. So I think that's your answer, your wheel got retrofitted with a shorter cassette body.