pete75 wrote:
Yes but you can get exactly the same frame designs without ugly looking tig welds. For example compare the tube joints on this lugless frame with the one illustrated above. The Hobbs frame would doubtless build up into a beautiful bike. Peugeot used smooth finished lugless joins on their frames for years so it's obviously suitable for mass production.
although 'it' isn't the same thing at all; the Peugeot scheme used internal lugs and pre-placed rings of spelter. Hobbs certainly didn't do any such thing.
barrym wrote: I know a little knowledge is a dangerous thing, but I can't help thinking that welding, even TIG, is exposing the metal to too much heat which will alter its carefully designed properties to function as intended. Clearly it can't be too bad as we don't see bent/collapsed frames everywhere. Only time will tell if they last as long as the lugged ones we see still functioning well.
Am I over thinking this?
Given that some expert folk spend their lives thinking about this sort of thing and nothing else, I don't think it is possible to truly 'overthink it'....
Welding metallurgy is really complicated! But when all is said and done you have to make a choice and the choice is a lot simpler than considerations of the minutiae of steel metallurgy... The reason frames don't collapse is that the tube walls in good frames are butted so that there is adequate strength near the joints despite the vagaries of the joining process and the effect it has on the steel. Frames can still fatigue though, and most TIG welded frames will eventually break, via fatigue, with the failure starting in or near a weldment.
TIG welding wasn't used in bike frames for many years because such fatigue failures are pretty much inevitable; a 'failure of conception' if you like. However in practice, frames of all kinds are more likely to break through failures in realisation than failures in conception; in other words whether the scheme was inherently good or bad, the quality of it's implementation would be the thing that would most likely dominate the outcome.
Anyway, whilst I do like the look of lugs, I think it unlikely I'd find a frame that would meet my other criteria than has them.
I might be a question of having such a frame built for you.
Beauty is as beauty does!
cheers
but I still think bicycles look better with lugs.
Actually there are any number of sloping TT bikes, especially Genesis, that have appeal. If your pic is the bike I'm thinking of, that's one!
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