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...components/FH/
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...components/FH/
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.
Thanks also for reminding me about Shimano's techdocs site. Lots of
detailed goodness there.
--
Ryan Cousineau
http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos