RIM BREAKAGE
Brad Poland
I ride a Bridgestone RB-1 and weigh 200lbs. The first rim was a 32 spoke
wolber box rim that lasted 3 months. The bike shop replaced it with a
matrix aero rim. It has lasted 9 months, but on last nights ride I hit
a small pot hole and boom the spokes around the valve stem looked like
they were about to pull trough the rim. The rim is cracked around these
spokes. What is the normal life time of these rims? Would the aero rim
have lasted longer if I hadn't hit the pot hole? What other rims/wheels
would you suggest for a person like me? Thanks in advance.
Patrick McNally
(Brad Poland) wrote:
I have the same exact problem. I have an RB-1 and it came with Wolber GTX
rims. I was unimpressed as the rear spokes pulled through. My shop
replaced it with a Campy rim. That one split along the braking surface all
the way around the rim, like it was made out of wood or something. That's
when I had some Mavic MA-40's built up with 36 spokes. No problems
whatsoever. Since then I had some Mavic SUP Ceramics built with 32 spokes,
and the same thing. No problem. We're both heavier riders, we have to
baby the bike over tracks and stuff. Keep the tires inflated well too.
ãPatrick McNally+
______________________________________
ã Patrick McNally, BOB #2503
sr.hp.com
I'd like to second this Mavic recommendation.
Last weekend, I crashed my (two-day old) bike at about 20 mph or so.
The bike turned sideways in the air, and my full weight came down
on the rear wheel, which means that 215 pounds of human loaded a Mavic
SUP wheel in the wrong direction. Well, not only did the wheel
survive, but it only needed slight adjustments to three spokes to
true it up. This wheel hit the ground so hard that the tire actually
rolled off the rim (Umma-gummas, fully inflated) and the tube exploded.
But the wheel was fine. I am *very* impressed.
Mavic SUP wheel, 36 butted spokes, 3-cross pattern, Dura-Ace hub.
Built by Paul Brown in Santa Rosa, California, who recommended
the wheel and probably saved me from having to walk 20 miles home.
I think he deserves some credit for building a great wheel for me.
If only my knee had survived as well as the wheel, I'd be a
competely happy camper.
Dan Pleasant
Michael Taffe
>I've cycling for about a year now and have gone through 2 rear rims.
>matrix aero rim. It has lasted 9 months, but on last nights ride I hit
>a small pot hole and boom the spokes around the valve stem looked like
>they were about to pull trough the rim. The rim is cracked around these
>spokes. What is the normal life time of these rims?
The normal lifetime of the Matrix (Drek house brand!) ISO-CII rims
is pretty darn short, as far as I can tell. (I assume this is what
you were using). As others have suggested, other rims may give you
better performance. The only other thing is that you may want to
think about your weight and the way that you ride (carefully steer
around all obstacles?... or just bash ahead, usually). It may be
that you need heavier rims or maybe more spokes (36).
mike
--
Mike Taffe *
mta...@ucsd.edu *
*
Joshua Putnam
>I've cycling for about a year now and have gone through 2 rear rims.
>I ride a Bridgestone RB-1 and weigh 200lbs. The first rim was a 32 spoke
>wolber box rim that lasted 3 months.
I'd suggest switching to 36 hole hubs and using something like an
MA-2. At your weight you're putting almost as much load on the
wheels as a 160 lb rider with a loaded toruing bike.
The double eyelets of the MA-2/MA-40 help spread the load away
from the spoke hole, something the Matrix aero rim doesn't do.
36 holes spread the load over more holes, thus less load per
hole tries to flex the rim.
--
If citizens, attaining equality, were to remain ignorant and
coarse, it would be difficult to forsee any limit to the stupid
excesses into which their selfishness might lead them.
-- Alexis de Tocqueville, _Democracy in America_