On Mar 13, 5:56 am, "Qui si parla Campagnolo"
wrote:
On Mar 12, 7:26 pm, Ryan Cousineau wrote:





In article ,

"bfd" wrote:
"Ryan Cousineau" wrote in message
...
A friend has a set of 10-speed Dura-Ace wheels. He wants to sell them. A
potential buyer has an 8-speed bike. You see the problem...

1) Can these DA hubs be "downgraded" with a (apparently steel) freehub
from the 8/9/10-compatible 105 hubs?

2) are these freehubs readily available in the parts channels yet?

3) are these DA hubs compatible with the mainstream Shimano freehub
bodies that are available all over the place, not least possibly from
the new purchaser's previous set of wheels? I'm thinking of the
almost-universal Shimano hub that can be removed by pulling out the axle
and then unscrewing the freehub body with a 10mm hex wrench inserted
into where the axle was (it's great fun if you've never done this
before, mainly because you can't really see or believe that there's any
10mm hex flats to engage in there).

The basic answer to the above is No. The design of the DA 10 Model 7800 rear
hub is substantially different from any other Shimano hub - 8, 9 or 10.

For example, DA 10 Model 7800 rear hub, looks almost identical to the
current Campy 9/10 rear hub (from 2000-2006):

http://techdocs.shimano.com/media/te...e/EV/bikecompo...
EV-FH-7800-2252_v1_m56577569830608915.pdf

In contrast, all other Shimano rear hubs, from 8, 9, and 10 are more like
this:

http://techdocs.shimano.com/media/te...e/EV/bikecompo...
EV-FH-7700-1654_v1_m56577569830610236.pdf

Notice the different in ball bearing placement on the right, drive side.

The best bet for your friend is to either run 10 speed drive train and use
the DA 10 Model 7800 rear hub. Or just get any other Shimano rear hub and
use 8, 9 or 10. Good Luck!

Thanks for that answer. Makes sense. But I wonder why they changed it? I
thought the old design was considered superior to freewheels largely
because of the outboard bearings.

Cuz whern they stop making 7700 rear hubs and your 7700 hub goes
south, no parts, gotta have DA..gotta upgrade to 10s to have DA-
marketing-

This is interesting. Has Shimano stopped making the 7700 rear hub or
parts for it?

I have 2 DA 9 7700 rear hubs. I had to replaced a crack cone once (it
was expensive - like over $20!) Other than that, I just replace the
1/4" ball bearings periodically and put a little oil in the freehub
body. What else needs to be replaced?