UDH. Sucks? Or does it?

"Just riding along" - Photos suggest the derailleur snapped in two after a bad crash and that smacked into the frame rather than the hanger?

out of interest, whats the frame?

This has been my experience as well.  I can't find my post right now but I did two mechs in two days on a Basque MTB trip the other year. The first I know I put it through a narrow gap between two rocks, the second I was being super careful and it did feel like JRA.  Both times the mech was destroyed and into the spokes, the hanger rotated, and chunks taken out of the seat stay.

The first one was a place I'd bashed mechs on previous bikes - scraped/bent mech but a much less extreme failure mode.

I'm really not a fan.  the rotation just seems like a bad idea - I thought it was supposed to allow the mech to move backwards without being damaged but it seems to do nothing of the sort. 

 the hanger needs to be put on with a reverse thread, to a high torque (which meant buying a new torque wrench).

I can't help feeling this is an absolute master stroke by SRAM.  They've sold the industry into a new standard that is great for SRAM T type mechs but a much worse solution than manufacturers previous hanger designs for anyones else's mechs (I've wrecked a load of mechs and hangers over the years, but UDH is the only one thats' damaged the frame at at the same time) 

I've had one rotate as well, when it really shouldn't have, fortunately no damage done. Also don't like the fact that they're reverse threaded and quite easy to strip/snap in half, being made of some kind of plastic crap.

quite easy to strip/snap

thats a joy isn't it?  I did one not realising my old torque wrench didn't work both ways. Took me hours to extract it.  I know someone else who's had similar issues. 

you kind of have to ask how it can be part plastic and snap inconveniently but not do so to protect your mech and frame?

I've had three UDH frames and on none of them did the derailleur or hanger rotate like that. I wonder if a lot of the problems are down to how different manufacturers incorporate the hanger?

Posted by: b33k34

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I did one not realising my old torque wrench didn't work both ways

Same. I generally don't use a torque wrench. Zero problems. Start using one and suddenly I've got a stripped UDH and a dropper that doesn't want to return. Facepalm!

I snapped one as well, and was a total pain to get ths snapped half out the frame.I thought it was a good idea. Would not get another bike with one now 

Would not get another bike with one now 

good luck with that. I’m thinking it’s pushing me to switch to sram. Which of course was the plan. 

Bike is a Canyon SpectralON. Running the original hanger which is metal with a plastic shroud. The plastic section (I assume) stops the rotation. I'll have a closer look later today.

I was in front when happened, so I didn't see the incident. Not a high speed crash though, most likely clipped a rock. I'm thinking of weakening the replacement hanger somehow? Some small holes in a line above the mech mount perhaps? Suggestions welcome.

I might also think about a strip of aluminium bonded to the top of the swinging arm to spread the load if it happens again? Sods law says if I do this it will never be needed.

Happened to me last week, but I think i hit a rock. The shimano axle failed rather than the udh hanger. The UDH hanger rotated and was undamaged. Had similar damage the the chainstay/dropout as well.

I've had a UDH rotate and bend.

Son had an XT derrailleur snap recently but not with a UDH.

His coach was riding behind at the time and said he didn't hit anything.

I don't seem to have a picture of the first I broke, this was the second one.  There is a minor scrape on the mech but really not much for it to have completely self destructed. 

the day before the main link snapped, both plates bent, both jockey wheels snapped.

the other pic is the result of over tightening.  

Erm anyone with one of those broken hanger, wanna send me the bolt? (happy to pay costs)

I somehow stripped the axle thread, and have stolen my spare's bolt to fix it.. got a unbroken hanger with no bolt (& a new one on it's way, but hey ho).

@z1ppy

I take it you mean the LH thread bolt? Happy to send you the one of the above bike. Message me.

Managed to break one while assembling a bike that had arrived disassembled in the post, on the plus side it was easy to get a spare.

My Gen 2 Levo still has the Spesh proprietary hanger and the mech rotated and snapped while the hanger remained in one piece much like the ones above so I take it as a "shit happens" kinda thing.

If there was a SRAM invention that really needs drowning in a sack it's torque caps. Ruins every ride where a wheel has to be removed.

I've hand an slx mech fail like that on a non-udh hanger. I figure UDH will now get all the hanger related ire that was previously directed at specific implentations.

Torque caps are a good mitigation to bolt through reducing the clamping force, and hence stiffness, of the wheel-fork interface. The frustrating thing is wheels don't tend to come with them.

If there was a SRAM invention that really needs drowning in a sack it's torque caps. Ruins every ride where a wheel has to be removed.

Every time I do this, I remind myself to 3D print some spacers to slip over the hub ends, I never do 😂

I don't understand why they don't just implement 20mm boost or whatever it's called, there's presumably enough meat in all their castings already, just stick a 20mm bit in the machine.

1) Most hubs are compatible anyway.  Compatibility isn't a problem for OEM's anyway and aftermarket the Venn diagram for people buying 38's and people running anything more bling than generic OEM hubs and therefore compatible is probably a perfect circle. 

2) Even most old 20mm hubs can be converted, they have a 110mm axle, it just needs a 5mm disk spacer.

3) It leaves Fox looking a bit silly with XC axles on their big forks