Originally Posted by
gomango
Framebuilders' signature talent and expertise.
Plain and simple.
Their vision of a what a proper road bicycle should look like and ride like.
In the case of Chris Kvale though, we won't have to worry.
I can't imagine he will be building for many more years.
The amount of hand work that goes into his frames is astounding.
I happen to own three of his bicycles, two of which fit me perfectly.
They are absolute jewels to behold, but far more importantly, they are the best riding bicycles I've ever owned.
Bar none.
Durability has never been an issue for Kvale either.
My next door neighbor has a 25 year old Kvale touring bike that rides like the day it was built.
I don't follow your argument about durability, unless you mean these are boutique frames designed to be hung on the wall rather than ridden. Any bike that is really made to be ridden is going to have the durability issue I refer to, namely: when you hit it against a brick wall hard enough, where does it bend? I will admit to not having Kvale's expertise, but seriously, do you mean to tell me a lesser frame is going to fail at the seat lug? No, it is not. The place any frame will fail is going to be at the head lugs as I described before.
I am not in the least disparaging Kvale's artistry, workmanship, expertise, etc. My point is the fancy workmanship around the seat cluster is not functional. It is artistic.
Originally Posted by
cudak888
The idea is sound, but wouldn't one would expect a butted frame to buckle - rather than bend - on the central, thin-walled section of the tubing?
I can see straight-gauge acting as such, but not butted tubing. What's more, a heat-treated tubeset will react completely differently.
-Kurt
For an experiment, try holding a cardboard tube, like from a poster, in your hands. Put one hand at each end, and using only your hands, try to bend it in the middle. You'll find you can put a temporary bow in it (much like you see the top tube of a frame doing when you apply the Park frame straightener tool), or you can bend over either end, but (unless you push it with your knee) you can't bend it in the middle.
Next experiment, try butting the cardboard tube by wrapping tape around it. With enough tape you can strengthen the ends enough that you can put a more serious temporary bow into the middle, but if you bend it hard enough for the tube to deflect, it will still deflect at the end, or at the end of the butt.
If you make a smooth transition from the reinforced area to the thin area, you allow a greater portion of the tube to flex without deflecting, thus increasing the amount of flexing force required to make the tube deflect. I'm sure that's the theory, anyway. In practice there will always be a point at which the tube will deflect somewhere, and at that point it will fail. Good workmanship can, at best, increase the amount of force required to make the tube fail.