>Given that the tubes in your rear triangle have wall thicknesses of around
>0.5mm, and you propose to move each 3mm out of alignment, and there is a
>piece of tubing joining these two stays rigidly together, you should
>consider that you are going to introduce permanent creases into the stays
>(assuming that they don't actually crack). This will dramatically weaken
>the structure, assuming that it doesn't actually fail when you are trying
...oh, bunk. john, are your eyes brown, or what? have you *ever* done
the above, or heard of anyone having a problem with "creasing" a chain-
stay (they're more on the order of 0.6-1.2mm wall thickness, btw), or
are you coming up with this as a thought exercise?? while you're at it,
you might figure out the angular bend that will result in
a deflection of 3mm in a tube 300+mm long. I'll give you a hint: it
approaches nil. clearly, you don't know what you're talking about, and
despite the fact that net "wisdom" is often worth exactly what you pay
for it, it annoys me when folks with a little knowledge purport to being
experts in the field, and their word is Fact, and Woe to He Who Disregards
those Words. like I said, bunk.
>this. Always remember that if your frame breaks while you are riding it, it
>could be your neck that is on the line.
*ahem* like I said...
>When I lived in Britain, and rode in races all bikes had to be checked
>before being allowed to start. The number one no-no was a frame with dented
>tubes. Your frame as modified would undoubtedly be rejected.
if it was properly re-set, they wouldn't even be able to detect it, much
less reject it. "dents??" again, have you ever done this? I have, and
unless you're talking about a heat-treated aluminum frame or some kind
of composite, you're not going to induce dents anywhere, even if you're
re-aligning a frame that's bent an order of magnitude more than
what you're proposing.
>However, there is a solution to your problem that is safe and not
>replacement of your frame in toto. Any competent frame builder can replace
>frame tubes. I should talk to one about replacement of your rear triangle.
>It should be quick and cheap, as almost no new tubes are needed. It may
***^!!!!!!!!!!!!^*** ..yeah, right. do you have any idea what
kind of project you're proposing?? I suppose the paint job that's
going to be necessitated is going to be 'quick and cheap,' too.
I'm not saying that your average schmoe-off-the-street can do
this correctly (don't try this at home, folks) (though, on the
balance, neither do you have to be a brain surgeon..), but with
some practice, it's really pretty easy. it's just a matter of
getting a 'feel' for how much force to exert, just as straight-
ening potatoe-chipped wheels is possible (not to mention fun,
and profitable) if you know what you're doing. I do.
bruce "frames stretched while you wait" krueger