I'm upgrading an old MTB for commuting, it had a 5 speed on the back but I'm going to be putting on a new 26" rear wheel with a 7 speed cassette because the freewheel axle wobbles, makes noises and is clearly done. The rear derailleur needs replacing because it doesn't changing gears properly and it jumps out of some gears. So, I got a new chain, front & rear derailleur and I'm just waiting on the 7 speed gear selectors, all cheap parts but all I need.

The only problem is whether I got the right rear derailleur for the bike. There is hanger mount and direct mount, my old derailleur seems to be a kind of hanger mount but I read direct mount is better so I ordered that.

Can you tell me if the new derailleur will work with the new 7 speed cassette, I know it says 6 speed but it has enough travel to go from the spokes to the smallest gear. The way is sits on the bike is pretty far back compared to what was there before.

Old Derailleur here

New Derailleur

  • You don’t appear to have a direct mount hanger, so I would say you got the wrong derailleur. A direct mount hanger points backwards diagonally from the dropout instead of making the usual L-shaped turn from a straight hanger and extension piece (often known as the b-link).
    – MaplePanda
    Commented Aug 11, 2020 at 8:49
  • Direct mount goes right in line with the cassette - where the big nut is above? Yeah I think it's definitely the wrong dérailleur now that I look at it. Do you think it would still work though?
    – Aindriú
    Commented Aug 11, 2020 at 9:21
  • 1
    See how your derailleur hanger points straight downwards? A direct mount hanger would point diagonally left instead. If you can get it to shift fine, you’re golden. You’re not going to break anything.
    – MaplePanda
    Commented Aug 11, 2020 at 20:44
  • I tried swapping it in but couldn't, I would need to break the chain, so I could end up using 2 chains (I have no quick links). Anyway I'm going to go with another derailleur - Shimano Tourney RD-TY300. Thanks for your help !
    – Aindriú
    Commented Aug 11, 2020 at 21:49


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