OK, I like road bikes and drop bars. Looking at a new titanium frame.
I'm an old fart, not as limber as I used to be. Consequently I need handlebars quite a bit higher than the norm. Actually, what works best for me is to use fork with uncut alloy steerer with high-rise stem mounted at the top of the steerer ala Sheldon:
Since this puts a lot of stress on the steer tube, I have mentioned to the framebuilder that I would like to leave the frame geometry exactly the same as on his standard frame, only lengthening the head tube at the top by a couple of inches.
He says "A long head tube extension above the top tube puts
a lot more stress on the top tube / head tube junction
(since the forces can't be dissipated in the steer tube
as easily). "
His solution is to modify the frame to incorporate the longer head tube I desire by raising the top tube proportionally, with the limiting factor being the standover height in the middle of the top tube.
His solution of course requires a custom frame which is more $$.
Besides the increased $$, I have reservations (1) that the frame is going to look like a weird mutant and (2) I don't really understand/buy into his reason for not just lengthening the head tube at the top.
I agree that using the whole length of the uncut steerer is going to magnify the stresses on the headtube, but those same stresses will be there whether the head tube is 4" or 7" (because the headset rigidly locks the steerer into the headtube).. If the head tube is 7" it will help support the steerer which is what I'm looking for.
We're talking about a metal frame here, not carbon. I am 145 pounds and never pedal while standing, due to physical limitations. So i'm comfortable with the use of the full steerer--it's a given--I'm using this arrangement on my 2 bikes now, and it works fine. The question is how best to have the head tube support the steerer. Maybe I should just go with the standard head-tube length, but on this model it's only 10.5cm--supporting a 30cm steerer with a hi-rise stem on top. Seems like it needs some help.
The framebuilder is a nice guy and I don't want to offend him.
What do you experts think about this?