Bike weight as a strength indicator?

Re:

Im a heavy phuker myself. Any properly built steel or Ti bike should have no issues being hammered by gentlemen of our corpulence. Good luck with the build HF :D
 
Re:

You know what engineers say: Light, strong, cheap; pick two.

The advantage of stronger metal is that it can be drawn into thinner-walled tubes to give a lighter frame. The frame will be just as strong for its intended use but dents and rust are more likely to be an issue. A lot of neglected 753 frames have now rusted out at the bottom end because rust eats 753 just as easily as it does hi-tensile steel - and there's a lot less wall to get through with 753.

Dents are more likely in thin-walled tube even if it is made of stronger metal. The force of a swinging handlebar, or whatever causes the dent, is so localised, that having metal with twice the UTS doesn't help much.
 
I always wondered the same. I had a lightweight frame that dented easily. I also have a very heavy raleigh frame which may be considered 'gas pipe frame' to the more up-turned nose individuals. The heavy one seems really strong, quite indestructible. I have never been one for lightweight bikes and gear.
The strength of the bike, does it come down to thickness of metal or quality?
Thanks
 
iow tom":2mp0dkgs said:
I always wondered the same. I had a lightweight frame that dented easily. I also have a very heavy raleigh frame which may be considered 'gas pipe frame' to the more up-turned nose individuals. The heavy one seems really strong, quite indestructible. I have never been one for lightweight bikes and gear.
The strength of the bike, does it come down to thickness of metal or quality?
Thanks

You are kind of missing the point a bit. The high quality stuff dents because of its very nature. Its designed to be light and strong with varying thicknesses throughout the tubing (butting) to create something very light and responsive. Some tube walls can be fractions of a millimetre at certain points of a frame. But its an expensive way of building hence the cost of say a 753 frame over a basic high tensile steel frame. It will also ride a hell of a lot better than a hi-ten frame.

Hi-ten 'gas pipe' frames are strong but heavy and very unresponsive so theres a reason for the 'up-turned' noses - these frames are usually slung together with absolutely no thought whatsoever to making the bike 'ride' nice.

Its all in the materials and implementation

Mid range steel frames are usually strong, reasonably light and many ride well.
 
My 'mountain' bike is made from Reynolds 531CS - road tubing! It is very flexible, lightweight and strong and has survived the Peak District with 90kg sat astride..

Pics tell a bazzilion words - brazing is joining two metals with a third. For bikes its usually brass (and some other ingredients). What is stronger depends on the build, lugs can pop out, welds can crack, braze can have holes in it.

Whatever it is, steel frames are so easy to repair over many other materials
 
I have not been one for paying extra for light weight frames as its lost on me. I dont wear light weight gear, buy light weight parts and i am quite heavy too. I take your point that its supposed to be a better feel to ride, i am yet to notice and if i spent enough time on one, i dare say i'd agree. Is it more likely to tear, more likely to rust through and more likely to dent? I am only asking as i dont know. I read alot of different things.
I have. 531 dawes but prefer the ride on the heavy raleigh.
I think mid range would suit my needs more?
I only say of the up turned noses as some can be super critical and say things like throw it in the garbage if its anything less than reynolds whatever number. I think if a bike still rides well and true after say 40 years, it deserves its place still in service, enjoyed by its rider.
 
You could try melting it, different metals melt at different temps :lol:

Seriously though, dont you know the make? surely that would help in determining the metal.

I have mostly rode steel frames, one day i took delivery of an easton frame and due to the unbelivable lightness i found myself putting it back down really carefully, same too when i got a yo eddy, soo light i was woried about it falling over and damaging. Silly i know as they are designed to be ridden off road. I think a lot of high end frames were/are built to serve a purpose, to win races, where they are not expected to be abused continuasly year after year. So personally i think that strength is ultimately sacrificed for weight.

Mark
 
'531' is a reasonable indicator but there are so many variants of 531 anyway. Plain gauge, butted, double butted, single tube, two tubes, and so on.

*531 cant be welded due to the Managnese content (Cro-Mn) and hideously poisonous!

245 and 4130 Cro-molybdenum (CroMo) is easily welded

753 is heat treated and loses yield strength if over heated hence silver soldering to keep the strength. Braising or welding turned 753 back to '531' strengths. Very expensive!

853 can be welded and is supplied in an unfinished state as it air hardens after welding or braising

953 and its Columbus equivalent dont rust simply because its almost stainless steel.

Some modern steel frames are now 0.35mm wall thickness along the top tube!
 
Back
Top