How often do you measure & straighten your alloy D. hanger?

[cavebear2]

Talking to a guy at a local LBS he reckons that if you ride a lot and have an alloy hanger then it needs to be straightened as much as every 3 months to maintain perfect shifting. (This not only includes forceful impact, but also DTD riding) I reckon this is OTT as I've got a RB that has done 42+K and has never had the hanger straightened. OK shifting isn't 100% perfect so it may be a little bent but I'm still happy to ride it and I'm pretty fussy about poor changing. On the other hand, I have a RB that has done 44K and I've just had the hanger straightened because it was quite bent, I think mostly from direct impact in crashes.

Based on the LBS cost to straighten I've just purchased a Park Tools guage for $80

[toolonglegs]

Check it when I am installing a new one... Check it after having and shifting issues. I only straighten them once or twice then bin them.

[Ross]

Sounds like a load of manure to me. Never had a bent hanger unless I crash or otherwise knock the derailleur. If you lean your bike against a wall or lay it on the ground then make sure the deraileur is facing out.

Park Tools have a tool for checking the alignment - http://www.parktool.com/blog/repair-hel ... -alignment

[jcjordan]

Quite a few people whom I know use Di2 have problems with the rear hanger. Something to do with the force of the shifting

[jules21]

220mm long M10 bolt from the hardware store!

[Mulger bill]

220mm long M10 bolt from the hardware store!

Wanna expand on that please Jules?

[jules21]

220mm long M10 bolt from the hardware store!

Wanna expand on that please Jules?

just thread the bolt into the hanger, where the RD would normally be inserted. then you have a long bolt which you can use to manipulate the hanger with. it's not as precise as the proper tool (as Ross linked to), but i've never found it necessary to be that precise - in my experience, as long as it's pretty straight it will shift OK.

the other thing is that a steel bolt will slightly strip the aluminium hanger thread, but not in any way that will harm its function. (you won't find an aluminium M10 bolt in a hardware store)

this is a bit of a 'bush mechanic' fix, but i swear by it

[Mulger bill]

Ahh, thanks Jules.

The other bush mechanicky bit I've heard of is to use the axle of the front wheel, supposedly the wheel rim provides good leverage for fine adjustment and makes a good gauge for visual checks.

Shaun