Damaged tension screw 'stop' on the rear mech hanger

Fatal Swan

Senior Retro Guru
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My Dyna Tech's mech hanger (non-replaceable, of course!) has a chewed-up 'stop' at the bottom, which is there for the B-tension screw to press against. The screw slides straight down instead of pressing into it. Anyone have any ideas? I've been thinking about fitting a nut on the end of the normal tension screw (or putting a socket-head bolt the wrong way aroun) so that the larger head hits the stop but I still don't think it'll give that reliable a contact.

On my road bike I've got a SRAM rear mech and on that design the tension screw presses into a stop that's built into the mech, and then a larger portion of that fits the shape of the hanger stop, so it looks like there's a much larger surface to contact between mech and hanger. I'm pretty sure that would do the trick, but are there any Shimano-compatible mechs that use that kind of design? On the Dyna Tech I'm currently running a Shimano 9-speed mid-cage rear mech (for 22-32-44 and 11-27). I don't mind switching the mech to fix it but I could really do without switching the STIs over to SRAM as well...
 
A pic would help but I'd have thought your first plan of using a nut (plus locking nut?) on the tension bolt should work. You could maybe file a flat on the hanger to increase contact area.
 
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Use whatever bodge is needed, could screw enough screw in and then bend it to fit too.

Modern Shimano Shadow mechs use a similar style to that SRAM you talk about.
 
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How chewed up is the frame stop? You could file it a bit to restore a bit more of the original contact area. Shimano mechs from around 07 ish onwards tend to have the stop built in to them.
 
you could bond a small nut to the end of the screw, the larger surface area might provide better purchase? it shouldn't need adjusting often, if at all
 
Thanks guys, that info on the modern Shimano mechs was just the kind of thing I was hoping for. I'm afraid I'm away from the bike at the moment so can't do photos but with the current mech the tension screw the angle has to be just right where it hits the stop and the last time I looked at it properly I wasn't that confident of getting a good square contact even with a nut on the end (probably the same for bending the screw). The built-in stop on the Shadow mechs would seem to be the more reliable approach, so I'll keep an eye out for one. Thanks!
 
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