euut tubing

[scarygerbil]

does anyone know what this type of tubing this is and if it is any good. The frame is lightweight but seems very stiff

 

[Illaveago]

I have seen that somewhere before but can't think where at the moment.

 

[Illaveago]

I just read a bit on Retrobike saying that Sun used it in the late 50s.

 

[biggs682]

thats a new one on me , there is always another name to remember

 

[scarygerbil]

yes it does seem to be used by sun. the guy at the LBS reckoned it was a lot stiffer than Reynolds tubing and would be most suited for a sprint bike

 

[mikeymustard]

Correct me if I'm wrong as I'm no metallurgist, but surely all steel has the same stiffness; the stiffness of a frame is dictated by either the thickness or the diameter of the tubes.

 

[midlife]

"Steel" is simply an alloy of Iron and Carbon, it's what you do after that what counts......... you can add various other constituents, Chrome, Vanadium, Manganese, Molybdenum, Niobium, Cobalt, Samarium etc in various amounts and then treat in various ways (heat, Coating, Pacification etc) to give a whole variety of materials with different properties, including stiffness (Young Modulus).

I wish I knew more than the A-Level stuff above.

Shaun

 

[mikeymustard]

It's a matter of semantics I know, but stiffness and strength are not the same, all steel alloys have the same young's modulus (approx 200GPa), what changes is their strength, so a higher strength alloy such as cro-mo or manganese molybdenum can have thinner walls for the same strength compared to cheap 1080 carbon steel

 

[Drago]

With Reynolds each series denotes not only the material but also the tube design, eg, seamless double butted etc. It's quite possible another manufacturer's tube set could be stiffer simply because the tube design itself is different.

 

[midlife]

It's a matter of semantics I know, but stiffness and strength are not the same, all steel alloys have the same young's modulus (approx 200GPa), what changes is their strength, so a higher strength alloy such as cro-mo or manganese molybdenum can have thinner walls for the same strength compared to cheap 1080 carbon steel

There you have it, my A level let's me down again . Maybe I should have said something like yield stress and not the Young modulus.

Shaun

 

[mikeymustard]

With Reynolds each series denotes not only the material but also the tube design, eg, seamless double butted etc. It's quite possible another manufacturer's tube set could be stiffer simply because the tube design itself is different.

That's true, but I'd guess that the geometry and builder's skill has as much if not more influence.

There you have it, my A level let's me down again . Maybe I should have said something like yield stress and not the Young modulus.

Shaun

Actually, far from trying to start an argument, I mentioned the stiffness 'cos I felt @scarygerbil 's LBS guy was talking out of his bum a bit - if sprinting is just about stiffness, then plain gauge 531 should be used, because its thicker walls would make the bike very stiff indeed!

 

[Fab Foodie]

That's true, but I'd guess that the geometry and builder's skill has as much if not more influence.


Actually, far from trying to start an argument, I mentioned the stiffness 'cos I felt @scarygerbil 's LBS guy was talking out of his bum a bit - if sprinting is just about stiffness, then plain gauge 531 should be used, because its thicker walls would make the bike very stiff indeed!

I have a 1950s Holdsworth in 531 plain gauge and it's bendier than a bendy thing ....

 

[scarygerbil]

I am sorry that I seem to have started an argument but first the LBS guy use to be a race mechanic so he has some idea about bikes.
stiffness in a frame is about lack of flex of frame when peddling ie. less flex means more power to the back wheel (compare a suspension MTB to a road bike).
but here is an article to muddy waters further but please don't forget my bike is from the fifties
https://janheine.wordpress.com/2011/10/03/science-and-bicycles-frame-stiffness/

 

[tyred]

I have a 1950s Holdsworth in 531 plain gauge and it's bendier than a bendy thing ....

Try Viagra.

 

[Fab Foodie]

Try Viagra.

I can't afford that much ....