Yes 853 is stronger because it’s heat-treated, and it also has the magic “air hardening” thing which is supposed to make the welds stronger. But 525 is strong enough.
I usually use 631 because I might as well have the air hardening (since I’m TIGging), it isn’t much more than 525, and gives me a bit more bling I don’t particularly want the heat treatment (which gives you more strength but less ductility). I figure they’re all strong enough for actual use and if I crash, I’d probably rather have the frame absorb some energy!
You can get the 631 1.0/0.6 blades direct from Reynolds here in UK (and I’m sure someone is importing them into US). I have used those a few times and they are really lovely. Of course use the thicker ones if you’re going disk brakes.
No, they’re not. Not by the time you get them. If you measure the wall on those they’re about 1.0 mm or a bit thicker at the top and bottom. The 0.5 mm claim is for the intermediate step, an untapered tube, that thickens up to around 1.0 mm after tapering.
But isn’t that also the case for the Columbus wall thickness? I haven’t ordered any fork blades yet but the tapered Zona chainstay I have is much thicker than the stated 0.6mm at the tip.
Well I have some EX5707s here. They do look a bit thinner at the bottom end, and seem to measure about 0.7mm, but there’s a bit of burring, and the usual black stuff on the inside.
Actually I have noticed before that Columbus stays (I think they were Cromor) seemed much thicker at the tapered end than Reynolds ones.
Infomercial is the key word. I can’t make a rocket that would take me to the moon and meets my safety tests, so I don’t list those on my catalog.
My take is that quote makes them sound like they have really rigorous tests. The reality is probably that they don’t want the liability of producing a fork. A steel fork is probably more expensive overall than a carbon fork at their volumes as well.
All the tapered tubes start out as round tubes. AS they ‘squash’ it down the taper the material has to go somewhere. As the taper diameter drops the wall thickness goes up.
I don’t particularly want the heat treatment (which gives you more strength but less ductility). I figure they’re all strong enough for actual use and if I crash, I’d probably rather have the frame absorb some energy!
