Bent KH hub flanges

I have de-laced my wheel in preperation for my new rim, my flanges are realy quite bent. This is not from botched crankgrabs or grinds, I asure you. I always go to pedal and the worse bending is on the oposite side to my grabbing/grinding side.

The question, should I bend them back before I build my new wheel? or should I just leave them and lace it up as it is?


I had 2 KH hubs that bend like that: I bent them both back with a vice.
Don’t know how they are doing right know, because I sold them a whill ago.
But didn’t heard anything from the buyers, so I geuss still strong.
On the otherhand, I realy think Kris should handle this problem.
The K1 and Qu-ax hubs don’t have this problem.

Yes I have the same problem and it sucks a lot because the bented flanges pulled the spokes closer to the hub and now my rim is so bented that the tire wents out all the time.

The K1 hubs do have this problem, mine does it, actually my K1 Hub does it and my KH doesn’t.

Its possible that it has something to do with a smaller wheel where there is more force pulling the flanges together.

On my Muni’s I have always run a KH hub with no problem, on my trials I have run a K1 hub and had the flanges bend a couple times, although once was my own fault.

I just bend them back and they usually last as long as the rim does. I think if you keep the spoke tension even and maintain your wheelset it will happen less often.

Ok yea, I thought it would probably be best to bend them back thanks. Do they start off at 90 degrees to the axel or angled in slightly? Should I bend them completly back or to what seems like a resnable angle?

Bending them back will also make them stronger and less likely to bend another time, so it will probably end up being a good thing to do.

I would have thought bending any metal would make it weaker - but you learn something knew every day I spose!

Could someone post a picture of what the bent flanges look like? I’ve seen what they were describing before.

Haha, so would I but I just saw a Nova a couple weeks ago called “the secrets of the samurai swords” and yes, each time you bend metal it gets exponentially harder to bend.

Ok I will get some pics in a sec…

no that’s different. with samurai swords they bend it but then they hammer it out flat again. with flanges your not “folding” like they do with swords, you’re just fatiguing the metal. to see this in action take a paperclip and smooth it so that it’s like a pin. take the two ends and choose a point in the middle and just keep bending it back and forth at that spot and soon you will find that it has broken in two.

If bending metal made it stronger, then people would never break seatposts,seat stiffeners, or frames.

As I thought.

“A little knowledge is a dangerous thing.”

Metal folding, as used in Japanese sword making (and also in my wedding ring), does indeed make metal stronger–because it’s done while the metal is being forged. The molten metal makes stronger bonds. See the WikiPedia page on mokume-gane.

Bending metal after it has been forged always makes it weaker. I would not intentionally try to bend your hub flanges back, unless you need to to build the wheel properly.

My hub looks pretty skanky because I painted it black and I now I am brining it back to the original blue. It shows the bend clear enough though. Here you go…

What I also noticed is that where the worst of the bend was it has pulled the flange away from the axel and has slightly torn part of it. Shown in this photo…

I think that picture makes it clear that the “KH” stamp-outs on the hub flanges are a bad idea. I don’t think there’s any way that hub flange will perform properly. You can lace it back up and it’ll basically work, but it will probably continue to deform and might fail entirely.

Hmm maybe another email to the man himself wont go a miss.

No, I don’t think that this is right.

One of the speakers on the show took a roll of copper wire, easily bent it one way, bent it back took a little work, and then he couldn’t bend it again.

Although yes, it does make the metal stronger while it is being made.

look up ‘strain hardening’

If you’re quoting Alexander Pope it’s “a little learning is a dangerous thing”.

And yes, any material that exhibits strain hardening will have its sigma yield increase during yield, and under reload will exhibit a higher sigma yield than previously.

In layman’s terms, if you bend something such that is doesn’t bend back when you let go, then when you try to bend it again it will take more force to get it to bend permeanently (plastically).

This image shows a classic exmaple of strain hardening in a copper sample i ran a few months ago.


bend them back.
They’re weak for some reason. The same thing happened when Jerrick and I were relacing his rim.