Lightest Steel Frame?

[doctor-bond]

Here’s another: ex Peugeot team CX frame in 753 - 55cm 1725g

 

[Jonny69]

Ishiwata did by far the thinnest wall tubing. 015 would have been the lightest frame you could build, assuming you were light enough to ride it safely!

Some of the current Kasei tube sets used in NJS keirin are probably as light. Stronger steel and multiple butting too.

 

[doctor-bond]

Ishiwata claimed sub 1600g for unbuilt frame tubes (inc fork legs) in large 60cm size. Didn’t someone on here score a NOS 753 tubeset recently? Be good to get a weight check.

 

[vcballbat]

My Raleigh SBDU 753 Dynaflite fillet brazed at low temperature using silver solder. Size 54.5 c-c coming in at 1700g with chrome chain stay protector, forks less the crown race 600g.

 

[Canuk]

No, cantilever rear.

Yeah, but it says on the advert 7kg 900 gr, so 7.9kg, which is 17.5lbs. Not bad for a single chair wheel, 5 speed Steelie, of the era

 

[Canuk]

I'm sure I read that Jan Raas had a 753 Raleigh under 1500gr, that would be a small frame though. Probably a 21.5in

 

[Canuk]

8kg is decent, but a double chainring, front changer, lever and extra length of chain would probably put another kilo on it, which is about normal for a 531 road bike.

 

[vcballbat]

I'm sure I read that Jan Raas had a 753 Raleigh under 1500gr, that would be a small frame though. Probably a 21.5in

Jan rode a 56.5 c-c road frame, he may have used a slightly smaller track frame. 753 track frames would of course be lighter with shorter chain stays, fork blades and lack of braze on fittings.

 

[vcballbat]

Another one of my Raleigh SBDU 753 Dynaflite frames with a much thinner coat of paint weighing in at 1680g and 9.1kg built up. ..not bad for an old hub geared roadster

 

[Woz]

Personally think the weights from around the 50s are surprisingly daft light. Actual weight (what it includes / excludes) and published weights of complete bikes will be down to a bit of debate. Wished I weighed my own frame set to get a concrete number.

Back on the earlier posted Alex Singer - 7.9 kg, and note the 4/10 - that is the tubing wall thickness. It is stupidly daft thin and combined with skinny diameters it would make for a very light bike.

The wall thickness actually comes up the average same as the 753 track tubing according to this article - which is mental for something to go touring on.



Said it before, such a period with everything whittled away to almost nothing and riding on a wing and prayer was the way. It was the cutting edge of bicycle technology. Also posted this a while ago - from 1947.



It doesn't leave much to the imagination looking at the uber thin stays, etc. and a smattering of AL anorexia all over the place (usually undersized ) and moreover the physical volume of the parts isn't much at all. Most likely even the steel stuff would be drilled / hollowed / sculpted out where it could. Hell even some of the brake cables are more like todays gear cables

Alex Singer is stating this is 11.7 kg today. No doubt it is a much more robust bicycle but heavier than what would have entered very competitive bike trade shows etc. from more than 70 years ago.

https://www.cycles-alex-singer.fr/catalogue/randonneur-sportif.html