SF Cyclotouring

Ride reports and other ramblings from a San Francisco cyclist.


Fuji CX goes to 8 speed!

Last night I finally finished up some bike-tweaking that I've been
trying to get to for quite a while...

When I built the Fuji CX up I used some scrounged wheels I had in the
shop, consisting of some old Wolber rims, early 105 freewheel hubs,
and a 7-spd Sachs FW I've been hording in my parts drawer for at least
10 years. I manged to coax the 9-spd barcon to index on the 7-spd FW
using an extreme version of the "alternate cable routing" trick
described at sheldonbrown.com. At any rate, the rear wheel was
problematic at first, and gave me some dishing/truing problems, making
me think that the rim itself is warped. It's actually held up much
better than I expected, but the FW hub makes me nervous (even though
I'm lightweight, I've bent FW-hub axels before on both road bikes and
MTBs) and I really want 8 or 9 speed compatability to better index
with the 9-spd barcon shifter.

So, I kept looking for a good used cheap wheelset on the local
Craigslist, and I found one a few weeks ago -- a guy who lived 1 block
from me was selling a set of Mavic CXP-21s laced to current-gen/9-spd
105 hubs...and he sold 'em to me for $65, which I thought was a darn
good deal. I'm not too sure about the CXP-21 rims...they don't have
eyelets, and I'm a big fan of those (an aside: the CXP-22s DO have
eyelets). They're also about 1mm narrower than the tried-n-true Open
Pro or MA-2 rims, making me wonder about their capability for wider CX
tires. Finally, the oddest thing about them is that, presumably due
to their semi-aero profile, the sidewall braking surface is only about
7.3mm tall, compared to the 10-12mm found on Open Pros and other rims.
V-brake pads are actually TALLER than the rim sidewall, making pad
adjustment a more precise task.

Some poking around on the web made me realize that lots of CX bikes
come with these rims as OEM (e.g., Cannondale) so I figured that
they'd work well enough. I've spent random evenings over the past few
weeks adjusting the hubs (the grease is still fresh-n-clean!) and
truing the wheels, trying to achieve balanced spoke tension. I
initially thought these wheels were reasonably true, but after getting
them home and in the wheelstand I saw differently. Nothing horrible,
but certainly worse than I'd ride. The front rim also had a minor
sidewall ding that I didn't catch when I was buying them, either --
looks like somebody hit a curb or a big pothole or something with an
underinflated tire.

Finally, I spend some more time truing the wheels last night, and
finally got them "good enough". I'm reasonably happy with the
spoke-tension-balance in both wheels, but the front could be a little
straighter. I got some tires mounted (700x35mm foldable Specialized
TriCross -- thought I'd try 'em since they're "Yet Another Set of CX
Tires Kicking Around the Shop") and I also installed the
filth-n-grunge-caked-on XTR 12-32 8spd cassette I picked up for $5 at
last year's Veloswap (I thought it was 9spd when I bought it, DOH).
It cleaned up nicely with lots of elbow grease, an old toothbrush, and
some degreaser. It actually doesn't look too worn and I think it'll
work, which is great because it's LIGHT.

I mounted the wheels, adjusted the v-brakes to suit, and then
re-routed the rear derailleur cable to use the "standard" alternate
cable routing which is supposed to make 9-spd shifters index on an
8-spd cogset. I'm happy to report that works great (at least in the
workstand). Although I don't have a scale to weigh it, the bike feels
quite a bit lighter now, due to the freehub, XTR cassette, and lighter
tires. Looking foward to a quick test ride tonight after work!

On a tangential note, there's a Fuji CX just like mine up on Ebay
right now: http://tinyurl.com/qvjvx I'm curious to see what it sells


Blogger cyclofiend said...

Oh man! If that bike gets lighter, we're going to have to hide more rocks in your backpack...

Can't wait to see it on the trails!

-- Jim

12:56 PM  

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