DisplayERROR

I'm reposting a thread that was originally started in the road bike forum but it has evolved into a question more specific to the dura ace 7400 groupset.

I'm currently building a Eddy Merckx Corsa extra (2007 re-release of the 7-11). Still trying to figure out the hub situation but I've settle on the 28/32 spoke combo. In terms of spokes I guess i'll go with DT swiss 14/15/14, with a radial front and 3 cross back or 2x/3x combo. However, on hubs I'm still a little confused in terms of speeds. I have 8 speed shifters (SIS downtube) which being as period correct as possible would mean 8 speed uniglide hubs. However, looking for long term, I would want a hyperglide hub ( which I assume is the system that shimano uses now for all their hubs). Does that mean, for example, that I can pretty much get a 7900 hub + a 10 speed cassette and pull two cogs out and change the spacers and it would work? I know Shimano decided to do something goofy with the 7402 derailleur so i'm not sure on what to do here. In terms of compatability, what hub options do I have?

GrayJay

Dura-Ace compatibility info is all here https://www.sheldonbrown.com/dura-ace.html
8-speed hyperglide casettes and hubs were made from 1990 onward, should be easy enough to just find a period correct 8-speed hyperglide hub to use with your shifters. 7-11 team sponsorship existed through 1990 so you can be period correct and build it as a 1990 w/ hyperglide.

miamijim

They're a few things going on here...

1. Dura Ace 8speed levers need to be paired with a Dura Ace 8sp rear deraileur. NO exceptions. The hub and cassette are NOT relevant.
2. Shimano cassette hubs are available in either low or high depth splining. An 8sp cassette should work on the 7900 hub as it appears to of the low spline variety.

740X, 7700, 7850, 7900 all have low profile splines and will accept an 8speed cassette.
7800 has high profile splines and will NOT accept an 8s cassette

GrayJay

No exceptions EXCEPT you can also use any originally 6 or 7 speed DA rear deraileur (they are pretty much the same as 8-speed) or EXCEPT use any other indexed shimano derailleur if you utilize alternate B cable attachement to vary the derailleur shift ratio as detailed by sheldon.

DisplayERROR

Ok great, so I do have a 7402 which I believe is the 8-speed deraileur. But in terms of cassettes, would I be left to finding an 8 speed HG cassette or could I buy a new cassette that might be a higher speed, take a few cogs out and slap in some spacers?

sethco

Cog thickness and spacing are different on 8, 9 (I think) and 10 speed cassettes. You might be able to get it to work but it sounds like a pain to me. 8 speed cassettes are still available, for example from Harris: https://sheldonbrown.com/harris/k7.html#8. I would just get one of those.

jan nikolajsen 

All your questions may already have been answered, but let me add that the 74xx rear hub that I had, and just sold, was threaded to accept both Uni and Hyper cassette.