Steven wrote:
> So what do you do when getting a frame that's 1.25 cm larger
> reduces your standover clearance to almost nothing, moves you
> another 1 cm behind the bottom bracket, and lengthens the top
> tube enough that the stem now required is too short for a
> properly handling bike because it doesn't put enough weight
> on the front wheel?
>
> Sometimes head tube extensions are necessary.
Sounds like you're talking about choosing between 2 sizes of a stock frame. If the frame can be designed any which way, being a larger seat tube size doesn't affect the setback or TT length at all.
In all my years as a custom frame builder I never saw a case where a head tube extension was what I'd call necessary. If someone needed the bars higher than a standard stem would allow, while still preserving standover clearance and a level toptube, I'd be more inclined to (1) buy or make a taller stem or (2) slope the TT - or sometimes both. Those methods can always put the bars right where you want 'em.
They aren't better than a head tube extension, I'll admit, except aesthetically (to me).
Do we all agree there's no real difference, other than aesthetic, if we're talking about custom frames? Certainly when a certain list member said head tube extensions are "stupid" he wasn't being very thoughtful, as they obviously are a valid way to achieve a goal. I just don't believe they're ever the only way.
Mark Bulgier
Seattle, Wa USA