Ti forks...what is the true demand?
- Thread starter rody
- Start date
With all due respect Mike, I think it is!MikeD":1ef3gngy said:
Surely we can agree that, weight for weight, ti is stiffer and stronger than steel. That's why steel frames can't get much below 4lbs without becoming too flexy/weak for mtb use, whereas ti can get close to 3lbs. Although I believe that the limiting factor with ti is more flex than strength - i.e., a 3lb ti frame wouldn't break, but it would be far too flexy for mtb. Which I guess is why ti frames are generally not made of butted tubes.
My triple-butted P2s have an external diameter of 25.4mm at the base, increasing to 27mm at the top. That corresponds to the advertised 1.3-0.8-0.5 butting profile. And I think people generally find P2s stiff enough. I believe that a ti P2 weighs about 1.4-1.5lbs, which roughly corresponds to the 3:4 ratio of ti:steel frames.
Assuming that 3lbs of ti is roughly as stiff/strong as 4lbs of steel and that steel is 1.75 times as dense as ti, the magic of excel suggests that a gauge of c1.1mm of ti is needed with a 25.4 external diameter to give the strength/stiffness of a steel P2 at three quarters the weight. Or maybe 1.3-0.9 if butted.
But I expect Rody has made rather more complex calculations than that!
Especially bearing in mind that all Konas are total rubbish, I don't expect you'll think much of this picture of a ti Project 2 then Kev?MadCowKev":wvc5qrxa said:Even if a 1" ti leg was as stiff as a 1" steel I would still want at least a 1 1/4" leg for aesthetic reasons.
This is retrobike after all. Its all about form over function
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MikeD
Senior Retro Guru
Surely we can agree that, weight for weight, ti is stiffer and stronger than steel.
Stronger yes. Stiffer no - steel has a modulus of elasticity about twice that of titanium. Which is why you need bigger/thicker tubes to make an equally stiff structure.
And I think people generally find P2s stiff enough.
Indeed so. My point is that to match that stiffness in Ti (and I'm conveniently ignoring stuff like how the crown is constructed, how the dropouts are attached etc - just thinking of it as two tubes) you'd have to make it generally bigger and, as a direct result, heavier. It would, as you correctly point out, be tough as the old boots of legend, of course ;-)
Stronger yes. Stiffer no - steel has a modulus of elasticity about twice that of titanium. Which is why you need bigger/thicker tubes to make an equally stiff structure.
And I think people generally find P2s stiff enough.
Indeed so. My point is that to match that stiffness in Ti (and I'm conveniently ignoring stuff like how the crown is constructed, how the dropouts are attached etc - just thinking of it as two tubes) you'd have to make it generally bigger and, as a direct result, heavier. It would, as you correctly point out, be tough as the old boots of legend, of course ;-)
But if you follow the same logic, ti frames would need to be heavier than steel frames in order to be stiff enough to be worth riding. But they don't.MikeD":2bgc5vhk said:
And as I mentioned a ti P2 is a lot lighter than a steel P2 - I haven't been fortunate enough to ride a bike with a ti P2, but if you were right, they'd be so flexy that surely nobody would ever have paid the £700 they apparently used to cost?
scant":1j1vxdwu said:MikeD":1j1vxdwu said:
you've missed the point entirely. Ti is cooler
For those with no proper understanding of what 'cool' means probably.
If you would accept a ti example falls short in its technical abilities: There is not so much cool about putting all the additional effort and resources in an attempt to create an inferior fork.
Will be just another not so great achievement in mankind, a proove where often hopelessly fall short in bringing our species to another level.
Will people buy it? Of course they do. That is what people do, buy stuff!
Would think crisis, focus on preservionism instead of consumerism would switch away pethatic thoughts like this ...but okay, we can't expect everybody has seen the light yet.
Elev12k":1917lr91 said:scant":1917lr91 said:MikeD":1917lr91 said:
you've missed the point entirely. Ti is cooler
For those with no proper understanding of what 'cool' means probably.
If you would accept a ti example falls short in its technical abilities: There is not so much cool about putting all the additional effort and resources in an attempt to create an inferior fork.
Will be just another not so great achievement in mankind, a proove where often hopelessly fall short in bringing our species to another level.
Will people buy it? Of course they do. That is what people do, buy stuff!
Would think crisis, focus on preservionism instead of consumerism would switch away pethatic thoughts like this ...but okay, we can't expect everybody has seen the light yet.
have you noticed this is a retro forum yeh? 90% of the stuff on here is bought purely for the coolness aspect & doesnt work so well
MikeD
Senior Retro Guru
A frame is not a fork. A fork is a cantilevered beam, a frame is a truss. It's an inherently stiffer structure. People are also more tolerant of whippy frames than twangy forks. Ti frames that are lighter than steel frames are generally more flexible, but for many people that's the appeal. "Worth riding" is a subjective concept.
Hardly anybody did. Why do you think they're rare?
Because £700 is a ridiculous price!MikeD":3l8e2swo said:
Which was presumably Rody's point in starting this thread. He isn't an idiot, as you seem to think. He has told us he can build a good ti fork lighter than a steel one, and he knows his stuff so if he says that I believe it. But it would cost c$400, which means maybe £400 over here with carriage and taxes, and he was wondering whether people would pay that. My guess is there's only a minute market in the UK at that price, but a rather bigger one in the US.
