I got a pair of Reynolds 853 fork legs for disc brakes (EX2720) for my personal rando-commuter.
They are pre-raked for 45mm, but I need them to be 65mm.
Only now I realise that they are heat treated and bending heat treated steel is usually not the best.
Does anyone have experience with bendinig these specific fork legs?
I usually rake on a wooden die with 115mm CLR if I remember correct. I have another one which is 230mm CLR or so.
That 45mm measurement actually does not correlate to the final rake. Once you add the dropouts the offset will extend about 20mm so you should be spot on.
I made the same mistake and originally ordered the 45mm thinking it would work great for my 50mm rake fork but I actually needed the 30mm Blades and it worked out nicely.
I use Long Shen Dropouts for reference
You’re probably right.
I have previously had to bend them further though. But I might just find a pair of dropouts that’ll give me the extra offset.
Would still be interested to hear if anyone has knowledge or experience with bending these legs 
I’m interested in this too. Is there really no one here who has added rake on those bad boys?
Your wooden form probably isn’t strong enough, might need to upgrade to metal.
When I was at Santana, right when they were starting up in the '70s, I remember we scratched our heads a bit when the special Santana blades arrived from Ishiwata. They were huge, looked like cricket bats, and they thickened up quite a bit down at the bottom from the tapering. We built the raker into the structural I-beam holding up the building, and used a lever that was, oh, maybe ten feet long? (brushing aside the cobwebs in my memory), and it still wasn’t easy. Hydraulic piston would probably be the smart move if you don’t have room for the proverbial ten foot pole.
That’s assuming they will bend without kinking or cracking. But I bet they will, it’s just getting enough bending force that’s the problem.
I would say bulgie is right- it’s probably possible, in theory at least. In reality, these are monstrously strong and practically impossible to manipulate. So much so that I would caution there’s little room for fixing alignment errors after the fork is complete. Any cold setting you do will happen in the crown, not the blades.
As I understand it, Reynolds rakes these before the final heat treat. I don’t know what the minimum quantity is, but I’ve heard you can get them in the annealed state, bend as you wish, and send them back for the final heat treat. Personally, unless it’s a really special case, I use the 631 version which is the same alloy with a less aggressive heat treat.
Sure, you can squeeze 15-20mm more out of the 853 “45mm Rake” blades. I’ve done it several times, and just did a pair…
These were the beefier, 1.1mm walled version:
There’s also a 1.0mm walled version that would be easier:
And the same blades are available in 631 too, which are no problem:
My bender is nothing special… Took a little effort, but nothing like some stuff I’ve bent. Reynolds uses, I believe, a ~9" radius die on these. I have a 5", 8", and 9" die… I’ve found the 8" works best for these blades.
(Those numbers on the scale are from the back edge of the table/blade, so call it 63mm.)
And yah, that “45mm Rake” isn’t where the fork will inevitably end up, obviously… That depends on a bunch of stuff.
One a related note, I’ve now got a pair of 853 “63mm Rake” blades on hand. Email me if you want them. Ha.
-Chris
Thanks for all the excellent information @ChrisBlandford. I found them to be in another league, well beyond some of the tandem blades and 90s TrueTemper unicrowns we used to use… maybe I just need to go to the gym for a couple weeks or put a longer lever on my bender 
-Corey
Thanks so much for such a detailed reply!
I’ll definitely give it a shot.
Lets see how the wooden bender holds up. If it doesn’t it’ll be a good excuse to make one out of metal 
Ha. Don’t get me wrong, they’re a bear! That 15-20mm is all I can get them to go. And I agree… I tried aligning them after building them into a fork one time and realized really quickly that was a bad idea.
Did you tried it already?
You know, I know nothing about disc brakes, but I know something about fork blades and rake, since I made the same mistake.
45 mm raked Reynolds blades give perfect 60 mm offset with drop outs, at least with QR-DOs. Bend radius is 15".
MOQ for 631 blades had been ten pieces some years ago.
So: check the effective offset with you drop outs before bending.
Haven’t done anything to the blades yet.
I’ll definitely measure where they land with the dropouts I intend to use before bending.
Alex Meade is a great source for aluminum fork bending mandrels, and lots of other frame tooling !
Great succes!
Had to reinforce my bender with some screws and clamps and use a 1 meter extender bar, but in the end it all went well 
Managed to get around 20mm more out of them, so I could trim the length from the tips and get a more continous curve without the straight section at the end. Very happy with the result.
Thanks for all the input and making me confident in trying! 
Time for slotting and brazing tomorrow 
