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Although when I mentioned stamped out box sections I probably should have elaborated. In my head I was thinking of fancy hydro-formed shapes with engineered flex/stiffness etc and different wall thickness at any given point. I'd assumed that's where the ductility comes into it?
Trek (I think) made a DH frame out of two halves welded together, a few years ago now. It was aluminium though.
How oversized do you want to go? you get something which has to be handled with care to avoid dents.
Well that's the beauty of greater specific strength. You can have an oversized tube with greater wall thickness for the same weight. Or the same tube geometry for less weight. Or any compromise thereof.
I'm not sure that yield strength is the limiting factor for chains... At some point, elastic extension
Uh huh, fair enough, maybe elastic deformation is a limiting factor in power transmission for sprinters, maybe yield strength and therefore weight is a limiting factor for climbers. My point was that saying 'strength is never a limiting factor' was rather glib of you, without having defined 'strength' or 'limiting factor'.
I rode one of these last season, it was great fun. Only goes downhill though.
lae-
You can have an oversized tube with greater wall thickness for the same weight.
Only if the density changes. We're talking about steel here, for most purposes we can treat the density as invariant for all steels, nearly all of them are between 7.7 and 7.9 and even an exotic alloy like AL6XN which is <50% Fe is only 8.1
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My point was that saying 'strength is never a limiting factor' was rather glib of you, without having defined 'strength' or 'limiting factor'
For almost any normal definitions of both "strength" and "limiting factor", my point substantially stands. The spokes in very low spoke count wheels are probably the closest thing we have on a bike to a piece of steel which is only just strong enough, and even there the limit seems to be that the wheel gets too flexy if we cut the total spoke cross section even further.
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maybe elastic deformation is a limiting factor in power transmission for sprinters, maybe yield strength and therefore weight is a limiting factor for climbers
Depends...
Road sprinter, 1500W, 53T chainring, 110rpm, chain tension 1200N
Climber grinding up Angliru, 500W, 34T chainring, 70rpm, chain tension 990NNot much in it
gbj_tester
Probably all true, people love to special. (Ti jewellery bikes etc.)
Although when I mentioned stamped out box sections I probably should have elaborated. In my head I was thinking of fancy hydro-formed shapes with engineered flex/stiffness etc and different wall thickness at any given point. I'd assumed that's where the ductility comes into it?