In article <[email hidden]>,
damyth said:dvt said:damyth said:Any technical reason you did not consider a 10-spd upgrade instead of
a 9?
I don't like the Shimano front indexing. I do like my Shimano derailers
and hubs. So I wanted Ergo levers, but I didn't want to upgrade
everything else. A Shiftmate would probably make Ergos shift 10-speed
Shimano nicely, but using Ergos directly with an otherwise Shimano setup
seems much cleaner.
And this path is much less expensive for guys like me that don't want to
pay for Ultegra/Chorus and above. You can't get 10-speed in a lower
Shimano group yet.
--
Dave
dvt at psu dot edu
OK, maybe I'm missing something.... According to Sheldon, a Shimano
Ultegra 10 cassette fits just fine on an Ultegra 8 (steel) fw body.
And Ergo levers (including Centaur) have 10 speeds and theoretically
work with Shimano Ultegra 10 cassette.
Everything else on the drivetrain, FD, RD, cranks, chainrings, rear
hub, except chain, can remain unchanged.
So I get/upgrade the following:
- Campy Centaur/Veloce levers
- Shimano 10-spd cassette
- Shimano 10 spd chain
I'm done, right? ๐ That's around $325 retail if I'm not mistaken.
Add a Campy rear derailer too. The front can stay, as Campy front
shifting isn't technically indexed: there's lots of clicks, and you can
shift and trim to heart's content.
The rear derailer, pace especially tricky figuring, should match the
shifter. post-2001 Campy 9-speed and all Campy 10-speed has the same
derailer pull ratio: 1.50. Earlier Campy 7-9 speed used 1.43. I'm
pulling this all out of my friend Dave's painfully gleaned spreadsheet.
The trick is to do the calculations such that the combinations of
shifter cable pull, derailer ratio, and cog spacing (C-C) work.
Here's a very simple example:
Campy 10 shifters pull 2.75 mm/shift, the derailer ratio is 1.5, which
means that the derailer moves 4.125mm per shift. Usefully, that's how
far apart Campy 10 cogs are.
Even more usefully, Shimano 10 cogs are also about 3.95 mm apart. You
can apparently get away with .2 mm of miss per cog, which shouldn't be
too surprising. That does add up to a bit less than a 2 mm error from
low to high, but in practice I think the shifting system can tolerate
that: it's within what Shimano would call the rideable range of
adjustment.
The fun example is this one: Campy 9-speed derailers from 2000 or
earlier use a 1.43 ratio. The newer Campy 9-speed shifters (2001+) have
a cable pull of 3.03 mm. Combine those two parts for a 4.33 mm derailer
movement per shift. Since Shimano 9-speed specifies 4.34 mm cog spacing,
and since .01 mm differences matter not a bit, this [censored] trio of
components work together perfectly.
The result is the drivetrain Dave specified for the Whip:
http://flickr.com/photos/rcousine/17347994/
It works really well. A season of successful racing on this bike has
made me a very happy man. Rebuildable shifters combined with the most
common style of wheels and cassettes out there. Best of both worlds.
It's not cool to admit it, but running Campy bits on this continent
imbues a bike with a certain cachet which is fun. And maybe more
importantly, I really like how these shifters feel. I could go back to
Shimano if necessary, but I ride Campy shifters by preference.
--
Ryan Cousineau [email hidden] 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