Will a 9 speed Shimano Deore derailleur be compatible with my 13-32 tooth freewheel?


1 Answer 1


Your RD-M591 is a 9 speed rear derailleur, and has these ratings:

Item Value
Low sprocket_Max 34T
Low sprocket_Min 28T
Capacity 45T
High sprocket Max 12T
High sprocket Min 11T

So nominally your high gears are not high enough, there's a reasonable chance it would work anyway. It could be a bit noisier and have slower shifting in the high/hard gears.

Your low gear of 32 is between 28 and 34, and will work fine at that end.

Do note this particular derailleur does not have a clutch. I'm not sure if there exists a 9 speed derailleur from Shimano with a clutch.

  • 2
    It must also be noted that Shimano is rather conservative concerning the MIN/MAX values. The system will not self-destruct for one or two teeth beyond the official values.
    – Carel
    Sep 21, 2021 at 11:52
  • I was unable to find the model number but it does say L-TWOO A5 on the outside. I believe it is the cheapest derailleur on amazon but that isn't exactly my problem with it, my problem is that the tension it provides is so incredibly weak that if I were to take it off a curb it would slap. I would love a clutch but with my speed and tooth range that would be impossible. All I want from my derailleur is a relatively strong tension that will prevent 60% chain slap. Do you think the Deore would suit my needs?
    – River
    Sep 22, 2021 at 6:37
  • @river I meant the model of the Deore derailleur you plan to buy, not the current one.
    – Criggie
    Sep 22, 2021 at 6:39
  • Oh, its RD-M591
    – River
    Sep 22, 2021 at 6:45
  • 1
    @River Put simply, derailleurs like RD-M591 being bad at controlling chain slap is the whole reason for the move to clutch derailleurs. In its day the answer would have been run a super thick chainstay protector, and then a chain guide if needed. The situation is no different now. It sounds like it may be better than what you have but it is a pretty humble MTB derailleur. Sep 23, 2021 at 3:32

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