Got a trek marlin 5 with a Bbshd kit fitted to it.

I am trying to change my 7 speed cassette size from 12-32t to 11-36t for more range. The standard derailleur Shimano Tourney TY300 that is fitted says it only works up to a max 34t.

 

Can someone recommend a 7 speed derailleur that will work with a 11-36t cassette?

 

Thanks

My 8 speed Shimano Acera apparently only does up to 34T yet it works fine on my replacement 36T.

You could put on a deriualler hanger extension or change one of your front chainrings.

Some people think Shimano are conservative with their deriualler capacities, they can cope with more teeth than stated

The stated ranges often allow for inappropriate big front to big rear gear setting. You'll almost certainly be OK with a few teeth bigger at the back as long as you are happy with some odd grindings if you (inadvertently or in an emergency) do go big to big.

A couple of extra teeth one may get away with though one might have to likely add a link to the chain length in case of tight chain stretch in BIG/BIG configuration.

One can try adjusing the B screw out to gain a bit of capacity.

Or as mentioned use a hanger extension quite cheap as a few quid for some of them.

Thanks for all the replies, i will order up a hanger extension and some extra chain links, as this seems to be mentioned a few times, and stick with the original derailleur.

You won't need the hanger extension, just screw the 'b' screw in until the change to bottom gear is smooth. Don't mess about with extra chain links, just buy a new chain.