> I have yet to understand the purpose of the concave rims, unless it was
> meant to provide a wider braking surface.
I believe the main thinking was strength for taco resistance so you
can go with a straight spoke pattern.
> I have tossed out (meaning donated) more of those thick thorn-proof
> tubes than I care to think of. I instead use the hard plastic Mr. Tuffy tyre
> liners, which are much lighter and don't interfere with taking the tyre on
> and off.
In Michigan, we didn't have to worry about thorns. Well, most of the
time, at least. Our issues were more related to tree roots, pockets of
very loose sand, mud, snow, wet leaves, skunks, poison ivy and quick
I tried puncture resistant tubes, but they were so stinking heavy that
I ditched those things after one ride. Spinning weight was so critical
that some people would actually shave off some of the tread from the
tires. I did try the liners for my commute wheels because I was
constantly picking up nails, screws and pieces of sharp metal. They
worked, but generally speaking, I usually kept my tire pressure
cranked up so high that not much would penetrate them anyway. I forgot
the brand/model now, but I had a set of tires that were lined with
Kevlar and were supposed to be puncture resistant. I can honestly say
that they weren't.
BMW is my wheels of choice now.
Themed Olympus Photo Exhibition: http://www.tope.nl/