I’m looking for a rear mech hanger alignment tool, has anyone got any recommendations for one that does what it’s meant to and won’t break the bank?

I use a big adjustable spanner clamped over the hanger where the mech attaches.

Get the cable tension set up so it shifts properly on the smallest 2 or 3 cogs, and observe what it does as you shift to the big end. Also look down on it when it’s in the middle of the cassette to see if the chain is straight as it leaves the bottom jockey wheel.

Take the mech off but leave the wheel on.

If the mech is shifting correctly at the small end of the cassette but not moving far enough per-click at the big end, bend it in towards the wheel. If it’s shifting ok at the small end but moving too far at the big end, bend it away from the wheel.

And if you need to, bend it to make the chain line straight.

Work slowly and carefully, re-attaching the mech after a bend to see the effect.

I should add that this has worked fine for me over the years with 1 steel frame and 3 alloy frames with no ill effects, but *be careful*

Park DAG-2

Park DAG2..

I’ve got one like this: Cyclus Hanger tool

I’m sure it’s not as well made as the Park tools one – but it’s not an everyday tool and has done me well enough for the last few years.