Tandem Tom

While poking around at a bike shop today I came across a Durace hub set in very good condition. It is for a 7 speed cassette. Now I had been thinking of an 8 speed and am now wondering if I should consider this set up?
Advice, thoughts?

dddd

It's all up to you, it's more the bike that counts so find something suitable for the build, based on the frame spacing, shifters used, etc...

Or is this one of those rare occasions where a component is the seed, from which an entire bike springs?

jiangshi

Dura Ace 7s is most certainly Uniglide only, and the cogs can be pricey. It is also difficult to convert to 8+s.

fietsbob

The 13~34t model K had a good set of tooth counts for Touring .. Dura Ace ?, Probably Not .

just Planned obsolescence made these Go Away, But 8 speeds are still showing up on New bikes.. definite lower affordable bike stuff. Not D-A

I'd ask at the LBS if they can still get New Drivers if they Fail, an Orphaned Hub will be No Fun in that future.

wrk101

+10 If its Uniglide, forget it.

OldsCOOL

Nice selection of cassettes over at Niagara Cycle. I picked up a 12-28 7sp HG for 13.00.

LeicaLad 

So, is it 126mm (7s) or 130mm (8s).

Not only is it likely Uniglide only, the Dura-Ace UG hubs require the threaded and 2nd position cogs that were made for Dura-Ace ONLY.

Post of photo, if you would.

dddd

I wasn't aware of anything special about Dura Ace cassette cogs, other than position 1, which has a smaller threaded diameter. There was even an 11t cog available that fit on the reduced threaded section of Dura-Ace 7s Uniglide cassette hubs.

Dura-Ace and Sante 7s freewheels have two threaded Uniglide cogs, position 1 with smaller external threads, and position 2 with the same threaded diameter as Shimano's 6s Uniglide freewheels.

verktyg 

Shimano Cassettes & Freehubs

verktyg


Chas.

LeicaLad 

I happily defer to dddd and to Chas on most issues. But the OP is talking about a cassette for a Dura-Ace hub. The 1st cog is the Dura-Ace only Uniglide threaded cog, but the second requires the splined type of cog with the spacer built onto it. Except for the 5-speed DA freehub, on the 6-8s versions, the second cog is needed to engage the freehub beyond the threads. If an ordinary UG cog is in position two, it will spin freely. SO, if you want to use the DA hub, you need Uniglide cogs AND both the 1st and 2nd position DA-only cogs. At least this is true of the two DA hubs on my workbench right now.

We still could use some photos of the OP's hub. . .

Tandem Tom

OP here.Thanks for your replies! Unfortunately I do not have a pic. But I think I will pass on the hub set. Thanks!

LeicaLad 

Here's an example. This is the 126mm 6s, but following dddd's advice, is being retuned w/ 9s spacers to run as a 7 speed. Note the second cog's built in/on spacers.

Don Marco

Would swapping in a HG compatible freehub work? I've done that on a couple late '80s 105 hubs, don't know if Dura-Ace is different somehow
.

OldsCOOL

If you plan on riding it much, this would be the way to go. Sorry I cant answer your question on D/A.

SimplySycles1

You have probably gathered by now, you need a special DA Uniglide cass. Same goes for the freehub, it does not attach to the hub shell in the "normal" manner. so switching to HG freehub requires a DA freehub. I may have an 8 speed DA freehub on a broken hub body. i can't pm, email me, wooba.flores@gmail.com

ThermionicScott 

Dura-Ace stuff has always scared me a little. Being the flagship group, it's generally great stuff, but those innovations didn't always trickle down to the rest of the groups, and if they didn't, replacement parts can be hard to find. Now, pedestrian 7-speed hubs like 600/105/RX100/RSX/Deore? I can't seem to say "no" if one is offered to me.

Jeff Wills

Dura-Ace cassette bodies attach to the hub differently than the rest of Shimano. I'm pretty sure you need a specific removal tool to swap the body, too.

There's been threads about this in the past. I think my friend DannoXYZ can tell you the ins and outs of these hubs.

IMO: unless you absolutely, positively, have to have Dura-Ace from that era, avoid these hubs.

DannoXYZ 

Jeff's right on, the Dura-Ace freehub bodies attach to the hub with a coarse-thread without using a separate hollow bolt. This allowed for on-the-road swaps of entire gearsets by having pre-built freehubs with cassette-cogs installed. You'd swap out the entire body+cassette in one piece. Unfortunately, you'd be hard-pressed to find that cassette-body removing tool nowadays, I had to mill my own from billet block the last time I needed one.



Dura-Ace 7-spd freehub-body is exclusively Uniglide. The move to 8-spd with the FH-7402 hubs had 8-spd Uniglide. Note the smaller-diameter threading to fit a 11t lockring-cog.


For a very brief period, the FH-7403 hubs had 8-spd Uniglide and Hyperglide. This one could take regular Uniglide lockring-cogs or Hyperglide lockrings (note internal-threading at the end):


The OP's hub can be upgraded to 8-spd HG by grinding out a wider-channel on the body and retaining the 1st thread-on Uniglide cog to work as a locking. Only unknown at the moment is whether the 1st cog on that Uniglide cassette is a 12t or 13t. Then you'd get a HG cassette starting with one tooth more to have a 2nd cog with built-in spacer.

For example, if it had a 12t Uniglide lockring-cog, you'd get a 7-spd 13-19t HG cassette and use 8-spd spacers. Or get a 8-spd 13-20t HG cassette and toss the 20t.