What is a Shadow derailler?

[Greasy Gilbert]

I've recently picked up an XT Deore 10 speed derailler (non clutch type) from a mate who was upgrading to a clutch type.
I'm having a bit of a faff making it work correctly in the low gears ( I will sort it though, that's not why I'm posting).
When I've Googled it, it's always referred to as being a Shadow type. Could someone explain to me what the difference is between this and a conventional rear mech?

 

[Cycleops]

Shimano says:
The mechanism rear derailleur, SHIMANO SHADOW RD, is intended for more aggressive riding. Its super low profile design carries many benefits. Because of its low profile and single tension construction, the derailleur does not hit the chain stay in rough riding conditions. The result is smooth and silent performance.

 

[Greasy Gilbert]

Shimano says:
The mechanism rear derailleur, SHIMANO SHADOW RD, is intended for more aggressive riding. Its super low profile design carries many benefits. Because of its low profile and single tension construction, the derailleur does not hit the chain stay in rough riding conditions. The result is smooth and silent performance.

Thanks for responding.
At 61 y/o I'm not sure I'll be needing the aggressive riding benefits but smooth and silent certainly appeals. Specially as its replacing a 15 year old LX Deore mech which should have seen the bin a long time ago. Thanks again, I appreciate your time.

 

[Cycleops]

I remember they made a bit of a thing about it when it came out a few years but it's been eclipsed by newer offerings.
Really for MTBs but no reason why you can't use it on a road bike or whatever.

 

[scragend]

I thought it just meant it doesn't stick out as far from the frame, so less chance of it snagging on something when riding on MTB trails.

I replaced a "normal" derailleur on my hybrid with a Shadow one (not because it was Shadow, I just needed a new derailleur). Didn't notice any difference from a normal one in the way it rode/shifted.

 

[I like Skol]

Shadow/non-shadow are interchangeable but.....

You still need the correct cable pull ratio to match mech to shifter. 9spd xt came in normal or shadow and rear mech was either m771 for traditional or m772 for shadow. Once you get to 10spd the pull ratio is often group specific so you might experience trouble trying to match, for instance, a 10 speed xt mech to a 10spd slx shifter

 

[Greasy Gilbert]

Shadow/non-shadow are interchangeable but.....

You still need the correct cable pull ratio to match mech to shifter. 9spd xt came in normal or shadow and rear mech was either m771 for traditional or m772 for shadow. Once you get to 10spd the pull ratio is often group specific so you might experience trouble trying to match, for instance, a 10 speed xt mech to a 10spd slx shifter

Hi, thanks for clearing that up, it explains why I'm having trouble setting it up with an old 9 speed Deore Shifter and 9 Speed cassette. It might find its way onto my old fiction shift mtb.

 

[Cycleops]

You should be absolutely fine with 9 speed.

 

[I like Skol]

You should be absolutely fine with 9 speed.

Really? I'd have to dig into the specs but I'm quite sure XT 10spd is a different pull ratio to 9spd.

 

[Drago]

Really? I'd have to dig into the specs but I'm quite sure XT 10spd is a different pull ratio to 9spd.

It is indeed.

 

[andrew_s]

Shimano road and MTB rear pull ratios were all the same up to 10-speed road and 9-speed MTB, except for 10-speed Tiagra 4700, which used the later 11-speed road pull ratio. That means that (except for Tiagra 4700) you can mostly mix and match road and MTB parts, but with 10-speed road shifters, you'd have to use a 9-speed MTB rear mech.

For 10-speed MTB and 11-speed Road, rear pull ratios changed.
To some extent, the loss of interchangeability doesn't matter too much, as by that stage road groupsets were using fairly large rear sprockets, and the usual reason for MTB mechs with road shifters was to allow larger sprockets than the 27T official/30T practical limit of road groupsets.

Shimano road and MTB front pull ratios have always been different

 

[scotsbikester]

As I understand it Shadow rear derailleurs are direct mount, and non-Shadow are conventional mount.

Though I have to say I'm not entirely clear of the difference. Even though I've got an M772 which is Shadow, therefore direct mount. This might explain - Direct vs standard - though if anybody here can provide a better explanation of direct mount vs conventional mount, I for one would love to know.

What I have seen, somewhere, is the idea that direct mount derailleurs don't wear at the top pivot as much as standard ones. For some reason.

 

[Cycleops]

It appears to be 10/11 compatible so will be a bit of a faff to change over to that. Maybe better to sell/swap for a 9 speed. I thought Shadow was older.

 

[scragend]

Though I have to say I'm not entirely clear of the difference. Even though I've got an M772 which is Shadow, therefore direct mount. This might explain - Direct vs standard - though if anybody here can provide a better explanation of direct mount vs conventional mount, I for one would love to know.

From the article:

A direct mount rear derailleur and a regular Shadow rear derailleur is the same thing, you just take off the B-link when you want to mount the derailleur to a direct mount hanger.

I'm still not 100% clear on the difference/the point of it all either, but at least the above explains to me why I was able to swap a non-Shadow for a Shadow without realising there was any difference in the first place!

 

[Greasy Gilbert]

Sorry if ive started something with my question. It's not a big issue whether it works or not really, I'm just the kind of bloke who needs to know how stuff works!
My understanding of things is that all the "work", if you like, is done at the shifter and the dérailleurs job is to push backwards and outwards when it's told to. My thinking is that it should work fine if the shifters a nine and the cassette is too. As long as the throw of the mech can cover the width of the cassette there should be no problem, although there seems to be a lot less backwards motion than on a conventional mech.
I think that my original question has been answered by @scotsbikester in that it's the mount that makes it different.