Shimano SIS Rear derailleur fixing problem I have the shimano sis rear derailleur which needs fixing. I took it off the wheel while I was fixing the puncture in the rear wheel. Now I am not able to fix it. It keeps coming off when I am pedaling especially while going on the hills.


As you can see the fitting end is not a ring. So it comes off easily. Also there is small bolt, not sure what it name is, is blocking the derailiuer going fully into the axle.



I need help please. Until this is fixed, I cant use the bike.

Thanks in advance.
What you need to do is ensure that the plate which the small bolt is attached to is located in the frame dropout. You should see one side of it is curved to match up to the drop out. You'll need either a Philips screwdriver or a 9mm wrench to tighten the bolt and hold your reach mech in place. I've attached a photo from Shimano's tech doc illustrating what I mean. Once the rear mech is back in place, tighten your wheel nut up and ensure the wheel is central in the frame, this type of design allows the wheel to occasionally slip to one side when you're tightening it, causing the rim/tyre to rub on the brake or frame. If you're using a torque wrench to tighten these parts then the mech bolt is 4nm and the rear wheel is around 32nm. 

Hope this helps!