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-   -   Help finding a vintage 1990s Dura Ace 8 speed hyperglide cassette? (https://www.bikeforums.net/bicycle-mechanics/694024-help-finding-vintage-1990s-dura-ace-8-speed-hyperglide-cassette.html)

kanakafitz 11-09-10 03:00 PM

Help finding a vintage 1990s Dura Ace 8 speed hyperglide cassette?
 
Hello all:

First time poster!

I have a vintage Dura Ace Groupo on my sweet Tom Kellogg Titanium Spectrum Frame. I am needing to replace the cassette and cogs (Hyperglide 7402 or 7401 version) and am having a very hard time finding a replacement.

Anyone know a source or a solution (aside from rebuilding the bike with a new groupo and wheels) so I can replace the cassette and/or the hyperglide cogs.

Thanks

wunderkind 11-09-10 03:06 PM

cassette and cogs? Why not just replace the entire thing.
Can you not just get a regular HG50 8spd cassette/cogs? It's only about $20-30. Any LBS carries 'em. You should get a new chain too.

Cynikal 11-09-10 04:57 PM

^DA 8 speed is different than standard so the above poster is incorrect. That being said, I do not know of a source for those cassettes. I would ask in the classic and vintage section of BF. They have more info there. Sounds like a sweet bike.

FastJake 11-09-10 05:10 PM


Originally Posted by Sheldon Brown
Myth: Dura-Ace cassettes have a different spacing, and are incompatible with other derailers/shifters.
Truth: No, all Shimano cassettes and freehubs with the same number of speeds use the same spacing, and index with any system configured for the same number of sprockets.

Myth: If you have a Dura-Ace hub, you need to use a Dura-Ace cassette.
Truth: The only truth in this is that for the old Uniglide systems, the smallest (threaded) sprocket used a smaller thread diameter in the Dura-Ace version, and that aluminum 2004-2007 Dura-Ace Freehub bodies with tall splines will only take 10-speed cassettes.


Originally Posted by Sheldon Brown
The major difference between pre-1997 Dura-Ace and the rest of the Shimano lines is the cable travel of the rear derailer. Old Dura-Ace used a shorter amount of cable travel per shift. This has to do with the geometry of the cable attachment. Since the cable moved a shorter distance per shift, effects of cable friction or inaccurate cable adjustment were magnified.

According to this, it seems you can use any 8-speed cassette on your 8-speed DA hub with your current shifter and derailer. The only place you run into problems is if you try to mix and match shifters/derailers.

wunderkind 11-09-10 05:16 PM


Originally Posted by Cynikal (Post 11761825)
^DA 8 speed is different than standard so the above poster is incorrect. That being said, I do not know of a source for those cassettes. I would ask in the classic and vintage section of BF. They have more info there. Sounds like a sweet bike.


http://komplexify.com/images/2010/Shipment-of-fail.jpg

Courtesy from the late Sheldon Brown. http://www.sheldonbrown.com/dura-ace.html

operator 11-09-10 08:20 PM

Haha, brutal.

Jeff Wills 11-09-10 09:50 PM


Originally Posted by Cynikal (Post 11761825)
^DA 8 speed is different than standard so the above poster is incorrect. That being said, I do not know of a source for those cassettes. I would ask in the classic and vintage section of BF. They have more info there. Sounds like a sweet bike.

Wrong. All Hyperglide cassettes use the same spline pattern and lockring threading*. You're thinking of pre-Hyperglide Uniglide cassettes, where the threaded cog on the Dura-Ace cassette had a unique, non-interchangeable thread.

*except for those that fit the 7800-series aluminum cassette bodies.

DannoXYZ 11-09-10 10:46 PM


Originally Posted by Cynikal (Post 11761825)
^DA 8 speed is different than standard so the above poster is incorrect. That being said, I do not know of a source for those cassettes. I would ask in the classic and vintage section of BF. They have more info there. Sounds like a sweet bike.

Only the shifters and RD are different in DA-8. The cassette has exactly the same 4.8mm c-t-c spacing as all other 8-spd cassettes. The OP can either replace cogs individually if he can find them (all the cogs are loose). Or it's easy to use any 8-spd cassette to replace it.

Kimmo 11-09-10 11:06 PM

*cough*4.8mm*cough*

DannoXYZ 11-09-10 11:29 PM


Originally Posted by Kimmo (Post 11763693)
*cough*4.8mm*cough*

Sorry, fixed it. :)

Kimmo 11-09-10 11:44 PM

I thought, hang on, that's the Campy 8spd and Shimano 7spd spacing ; )

DannoXYZ 11-09-10 11:47 PM

Yeah, got my spacings mixed up. I've been modifying a lot of Campy 8-spd to Shimano 8-spd spacing. Also converting a Suntour Winner 5-spd freewheel to 8-spd with Shimano spacing and simulating the Uniglide twisted-tooth profile. :)

DannoXYZ 11-10-10 02:24 PM

Some more clarification on Dura-ace freehubs. Here's an FH-7402 8-spd Uniglide freehub (note the smaller 32mm threaded end for 11t cog)::
http://i42.photobucket.com/albums/e3.../FH-7402sm.jpg
Interestingly enough, even though the FH-7400/7402 can accept a Uniglide 11t threaded top-cog, Shimano never made a 7/8-spd cassette for this hub with an 11t cog. The only cassettes that came with 11t top-cog was for the older Dura-ace AX and EX models in 5/6/7-spd. I don't like 11t cogs anyway, they wear too fast and the jump from 11t to 12t is much too large at 9%.


And the mythical FH-7403 8-spd Uniglide/Hyperglide freehub. The threaded end is more standard 34.5mm for non Dura-ace Uniglide cogs.
http://i42.photobucket.com/albums/e3.../FH-7403sm.jpg

Hyperglide cassettes of any kind works with this freehub (except for Hyperglide-C 11t cogs).

Cynikal 11-10-10 03:22 PM

Fair enough, I messed that up. I confused the RD with the cassette. Carry on.

DannoXYZ 11-10-10 04:58 PM


Originally Posted by kanakafitz (Post 11761193)
I have a vintage Dura Ace Groupo on my sweet Tom Kellogg Titanium Spectrum Frame. I am needing to replace the cassette and cogs (Hyperglide 7402 or 7401 version) and am having a very hard time finding a replacement.

Anyone know a source or a solution (aside from rebuilding the bike with a new groupo and wheels) so I can replace the cassette and/or the hyperglide cogs.

I just reviewed the OP and I don't know if the actual question has been answered. Assuming they an FH-7402 freehub, this is NOT Hyperglide compatible, it's Uniglide only. To fit a Hyperglide cassette on, they'd have to grind off the wider key on each sprocket and use the original threaded Uniglide top-cog to lock it all together.

Jeff Wills 11-10-10 10:26 PM


Originally Posted by DannoXYZ (Post 11767584)
I just reviewed the OP and I don't know if the actual question has been answered. Assuming they an FH-7402 freehub, this is NOT Hyperglide compatible, it's Uniglide only. To fit a Hyperglide cassette on, they'd have to grind off the wider key on each sprocket and use the original threaded Uniglide top-cog to lock it all together.

*Slaps head*... You are correct, Danno. The OP's hub is almost certainly Uniglide, not Hyperglide. 8-speed Dura-Ace Uniglide cassettes will be very rare, and very dear, indeed: http://cgi.ebay.com/ws/eBayISAPI.dll...m=390254854286

OP: you can clarify things immensely by posting a picture of your current cassette, particularly the right side. That will help us identify exactly what you have.

kanakafitz 11-15-10 11:59 AM

Well...WOW...my fairly basic question sure opened up a great discussion. The outcome...drum roll please...replaced Dura Ace Cassette with HG 50 Shimano 105 8 speed 12-25 cassette and a shimano hyperglide compatible chain. All is working, shifting, threading, and feeling nicely solid with no chain skip or weird shifting. Thanks to one and all for all the help, pictures, and very technical discussion. Carry on if you must, but I am a happy cyclist right now and no one is going to really know that my cassette is a lowly cassette at first glance unless I spill the beans. It's really the nut on the seat that makes the bike go and I love the frame...so it's resurrection in it's next life will be to be rewarded with a new groupo. Assuming nothing breaks on the frame!

DannoXYZ 11-15-10 12:25 PM

Ah, you must have the FH-7403 hub then. Good to hear you about your results! :)


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