Hi

I recently swapped my cassette, chain and installed new shifting cables.

everything is OK on the stand but on my test ride my chain is binding up and hitting my rear
stay

it appears to happen only when I'm climbing up my drive way and is fine on the flats

also appears to only effect my middle and granny not my big ring.

I'm a newbie "mechanic" so I'm not sure where to being trouble shooting the problem

This is tricky to diagnose without seeing the bike firsthand. Any chance on some pics of your drive train as it is currently setup. Helpfull would be closeups of the front and rear mech. Also a pic of the after it binds situation.

Have you turned the bike upside down and cycled through all gears without any trouble?

Two things to check just in case: Make sure your chain doesnt have any stiff links. Go one link at a time and make sure all of the links pivot smoothly. If you have this problem we can tell you how to fix it.

Do your Jockey wheels turn without any resistance, and your rear mechs hinges are all smooth?

Do you mean it's wrapping around the chainring and jamming against the underside of the stay? Classic 'chain suck' and happens most often when a new chain is used on a worn chainring. Sound like it might be time for new chainrings also.

https://www.fagan.co.za/Bikes/Csuck/

I believe your correct with the chain suck

unfortunately I'll miss a ride but it's my own fault because the bike should have been test ridden after all my changes

oh well time for a new middle ring and possibly a granny while I'm at it

You might need new chainrings, but maybe not. In the hope of being able to do your ride clean all the gunk off the granny and middle chainring, and lube your chain thoroughly with a decent wet chain lube. Often times chain sick is a chain lubrication problem, not a chainring problem.

Also chain suck occurs most often during the shift to the granny when slack is created before the RD can restore tension in the lower loop. Try dropping your cadence and even timing a pause for when the chain comes off the bottom of the larger rings during down shifts. This isn't ideal, and you really want the bike to be bulletproof for chainsuck, either with new rings if needed or good lubrication, but it might allow you to make your ride.

Chainsuck is often a sign of a tight link. A tight link is also common on a newly installed chain.

+1 Check this first.

you may be able to get away with removing your chainrings and flipping them over then reinstalling them backwards.

This is the poorman's method to getting a little more life out of a chainring.

-j