Ken Spencer said:I just bought a new Trek 2100, and actually read the manual. How
unusual for me!
It mentions that the top tube should not be used for clamping in a work
stand - I guess they are worried about crushing it. They suggest the
seat post.
The seat post in my bike is carbon fiber. And the bike is way off
balance if I were to clamp it there.
The fact that the bike's off balance is always a worry, but it should
be okay for light work. Be extra careful of hauling away at the
handlebars if you do, because there's a lot of leverage available that
way.
Quoted message said:But, OK, I will do that, but I am curious - is there any danger in
crushing or snapping the seat post as well?
Can the top tube be used, if I am *careful* about clamping it, or would
that be fatal?
Depends on bike - the cheaper the bike, the thicker the tube walls and
the more you can get away with. I wouldn't put a bike in a workstand
for anything involving lots of torque (anything stuck or rusted in, and
especially anything on the front end of the bike if you're clamping by
the seatpost).
I've bent posts and frames before, posts are a whole heap cheaper. And
carbon-fibre does not like being stressed in directions it wasn't
designed to be stressed in, so if I was you I'd get hold of a beaten up
old steel/alu seatpost and use that for clamping.
As far as your preferred stands go,
http://www.mtbr.com/reviews/Tools/product_88742.shtml suggests the Spin
Doctor one is a bit too cheap to be cheerful.
Some stands (like my shop's Park stand) have an adjustable setting on
the rotation adjustment, so you can set the torque required to rotate
the clamp. I'd suggest not cranking that up too high, then it's more
difficult to put too much oomph into the seatpost without the clamp
slipping. If you've got the sort where rotation is controlled by some
other system, that's obviously not an option.