I have a very nice bicycle made from Reynolds 531 tubes, and another that's much lower quality.
If I didn't have the "531" label on the first, and didn't know already that the second were very cheap, how could one tell what kind of steel they were made from?
Daniele
Without hacking samples of the metal and paying for a lab to test the sample:
Total weight of the bare frame, wall thickness of tubes in middle compared to end.
At one time the transfers were very closely controlled, as Joe Public you could get '531 respray' transfers from Reynolds, original 531 transfers only came with a set of frame tubes. Some frame refurbishers could also replace original transfers on a one for one basis, not sure if they were originals or copies.
The transfers are easy to obtain now... so anyone can make a fake.
Without a metallurgy lab, you can't say for sure what's in it. You'd have to anylyse the steel and do bending tests on it. The simplest way is to weigh the frame and see how thick the walls are
- experience /comparison will give some indication of the quality, not much else.
Angle grinder.
Of course, if you don't want to take an angle grinder to your bike, you will find it a lot more difficult.
Colin Bignell
it can be done using a handheld XRF analyser.
XRF involves bombarding the sample with x-rays. The metal then fluoresces. The sensor then detects the intensity and wavelength of the fluorescing radiation.
This will then give you the elemental composition of the steel.
Looking up the composition of various metals will then allow you to ascertain what specific alloy the steel is.
For XRF analysers, they are made by Niton and by Fischer and by Oxford Instruments.
Some XRF analysers have alloy libraries in them so they can be "smart" enough to tell you the alloy steel grade to save you working it out from the elemental composition.
They are also used by Scrap metal dealers...
The simplest way is simply to ride both bikes. It is very easy to tell a 531 frame from a cheap low quality steel bike.
They sound marvellous, but at what cost?
Leave both outside and see which one disappears quickest?
Diameter of seat pin is a clue. 531 DB is 27.2; plain gauge is 27 mm. Most gas-tube frames are 26.something. I've 'adjusted' frames for spacing of the rear dropouts and 531 needs a lot of force and tends to spring back. The cheap frames I've done went too far and needed sqeezing back in again.
These might be worth trying:
- Tap the top tube with your fingernail at various points along its length. I suspect the Reynolds tubing would have a more distinct higher pitched ring than the cheap tube. The tone might also vary more between points along it's length, because it would be double-butted, while the cheap frame would be plain gauge.
Are we allowed to look at the lugs?
- If the frame is lugged, look at the quality of them. The lugs on the Reynolds frame are likely to be thinner and fancier.
- Are the joints welded (slightly banded appearance) rather than brazed? From memory, I don't think Reynolds 531 tolerates welding temperatures very well, while other steel tubing does.
In article , PeterC writes
That's interesting, I've an old(ish) 531c frame that I 'spring' to fit a more modern wheel with an 8 speed block but I never thought to make a permanent stretch, too scared of doing permanent damage.
Did you just jack apart the dropouts or is there more to it than that?
That's all there is to it; I had to do that for my rear motorwheel - needed about 10mm extra. Supposedly 531 tubing all over on that frame and true enough, the stays did take a bit of persuading to stay opened.
I wouldn't bother. I'm in the same boat with a 531st frame that I tried to "cold set" to get a longer rear axle in (like yourself). I chickened out after using lots of force without bending it beyond its elastic limits. The wheel still fits and it's not that hard to spring it in and out. The biggest problem is the fact that the dropouts are no longer entirely parallel. Unless I tighten the Q/R skewers up really tight the wheel occasionally moves under power.
Tim
I needed more space for the block - not for more sprockets as in posts below, as in those days 5 seemed to be enough - but to reduce dishing of the rear wheel[1]. Because of this requirement, I wanted to bias the extra space to the gear side and basically was looking for about 5mm or so[2]. (in socks) I stood on the chain and seat stays of the nearside (with the frame on its side on a carpet) and heaved up on the other rear end. Took it about 30mm, released and measured - about half a mm! Tried harder and eventually got there. For some years now some frames have been built with biased spacing, so I might not have been wrong to do it. Seemed logical and I've never found any problem. Then just build the wheel and space the axle to suit.
[1] The tension in the spokes is proportional to the Tangent of the angle between the spokes and the axle. To keep the angle at 90 deg. against the force of the opposing spokes would need infinite tension and spokes ain't that strong. With a very dished wheel the angle is getting close to 90 deg., so any reduction is worth having. [2] I was trying to avoid exceeding the available max. spacing on the axle, as Campag Record rear axles were expensive and not easily available other than standard.
High tech then ;-)
That would be the ideal but I'm a tightwad and buy the best within budget online so they will be stock sizes.
I think I will end up following Tim's example and just make do although it kind of rules out a fast tube change on the back. I have no problems with sprocket clearance. I do find the springing of the stays a bit of a hassle so must think of a clever, light and portable jack for that purpose, possibly an a adaptor to fit a skewer to make use of the advantage of those always carried levers.
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