Replaced my 1×10 shimano 11-36 10 speed cassette with a sunrace 11-40. Wound b screw in and all seemed fine but when dropping from the third largest sprocket to 4th, the chain catches the inside of the derailleur before dropping onto the 4th sprocket. I only noticed this on the bike stand, when riding I don’t feel or hear it happening. I am slowly grinding a small groove into the derailleur. Do I need a goat link or should I not worry about it, winding the b screw in all the way doesn’t help. Thanks

Yes. Or eventually your groove will be big enough.
I was going to get a goatlink for mine, but then an 11speed mech appeared in the spares box and that works fine on a 10speed wide range cassette.

Try Goat Simulator

Thanks for the reply. I’ve been on the wolf industries site and it says the goat link needs to work with a derailleur with a clutch – mine is from the era before clutch mechs, my 1×10 set up works on a nw front ring only. So any recommendations for a different goat link manufacturer? Thanks

There is a cheap Chinese copy-ish. Widely available on eBay for about £2. It just bolts to the existing mech rather than replacing the part of the mech so should work with any mech. I wasn’t overly impressed but it does work without mega b screw tension and it’s cheap.