Long vs Medium derailleurs

[SwissMountainLeader]

Hello

Can anyone say if there's a difference between a long and Medium derailleur? I'm reading some internet sites saying it's pretty arbitrary and I can use a long in place of a Medium

replacing my bust derailleur is proving slightly more difficult than I originally thought

 

[Zimmerframe]

I'm normally a medium cage guy to avoid destruction (unsuccessfully). The focus has a long cage and so far no issues. I wonder if the chain to jockey angle is better on the long so less chance of branches being drawn in .

 

[SwissMountainLeader]

Thanks! That’s about what I’d decided as well. The LBS seem confident they can replace it anyway so I’m hopefully just ordering myself a spare.

I just made an error ordering the SGS or Long version so I’ve returned it and ordered a medium which will arrive in the morning. I don’t entirely share the 100% confidence the LBS have about their replacement, I’m more 80% But tomorrow I’ll either have their replacement or mine on the bike so that’s all good.

Maybe I should have kept the long version and sold it later at a profit

 

[KenX]

I bought a spare SLX derailleur a few weeks back, took me half a day to find one on the 'net.........

 

[SwissMountainLeader]

I bought a spare SLX derailleur a few weeks back, took me half a day to find one on the 'net.........

I found one in Switzerland in a few minutes. Spent a few hours staring at it and then ordered the wrong one ?

 

[Gary]

Generally speaking :
Long mech cages are for double and triple chainring drivetrains.
Short and super short are for close ratio cassettes.
And medium is for either mid range cassettes and multiple chainrings or 1x with a wide ratio cassette.

 

[SwissMountainLeader]

Generally speaking :
Long mech cages are for double and triple chainring drivetrains.
Short and super short are for close ratio cassettes.
And medium is for either mid range cassettes and multiple chainrings or 1x with a wide ratio cassette.

This is 1x wide ratio so that was the recommended part. Returning the wrong one was the only way to fix my error.

 

[Gary]

Medium or long cage would work just fine with 1X and a wide ratio cassette.
Infact using a long cage mech keeps the guide jockey wheels distance from the sprocket slightly more consistent throughout the gear range especially on a suspension frame.

 

[SwissMountainLeader]

So the final result was the LBS fitted a long derailleur which is an XT deore. It’s about 98% ok in that one or two in a hundred shifts seem a bit clunky. I also have the real original part from an internet supplier plus tomorrow a spare cassette and a chain I already had. I may use the chain on my analogue bike though.

it’s ok enough that I’ll let it stay assuming as a long dérailleur it’s likely I’ll rip it out again before too long ?

 

[SwissMountainLeader]

amazing, just torn the new one apart ?

this time a farmer had lost a coil of barbed wire in a field that got into my mech. I’ll need to check the tyres of course, I was able to ride out and didn’t lose any pressure. The LBS had fitted a long derailleur but I don’t think that really mattered, I think the same would have happened with a medium length as well. Fortunately, I now have an original one in a box ready to go. I’ve ordered yet another which is apparently the last one in stock at the distributor.

So that lasted 120km

 

[Gary]

Unlucky.

Or was it luck?

 

[SwissMountainLeader]

Unlucky.

Clustering. Or cluster-something

I did have a close look at what the LBS had done with the long dérailleur. They had to add a few links to a standard chain which did crunch a bit on some changes. So it should be better now

 

[OldBean]

Derailleurs suck ! the sooner they are replaced by gearboxes or Motors with more torque so you dont need gears at all ...that is the future.
E cars dont have gearboxes.

 

[Gary]

a long cage deraileur doesn't need any more links added than a meduim cage deraileur does.
(or did you mean something else?)

 

[SwissMountainLeader]

a long cage deraileur doesn't need any more links added than a meduim cage deraileur does.
(or did you mean something else?)

I do need to ask them exactly what occurred. It’s not really clear to me either. Removing the extra links gives me the exact same length as an HG54 out of the box, I compared it to a new one. Having mangled the LBS fitted XT derailleur it’s now hard to say but they did seem to need some extra links to get the XT to work, it may be my error in assuming that’s related to the lenght.

I kind of feel I’ve made a rather better of the repair although that’s unfair because I had the right part

 

[Gary]

IDK but if fitting a new chain. Regardless of mech cage. The combination of long chsinstays (29er Eebs I'm looking at you), a wide range cassette and suspension (chain growth) means many Eebs need a longer chain than what comes packaged (often just 116links)

 

[SwissMountainLeader]

That’s interesting, I can ask both the store and the Swiss manufacturer. That ought to shed some light.

 

[Zimmerframe]

Derailleurs suck ! the sooner they are replaced by gearboxes or Motors with more torque so you dont need gears at all ...that is the future.
E cars dont have gearboxes.

There's countless threads on this. A chain and derailleur, whilst being a bit like running through gorse bush with your nuts hanging out, are very efficient. Gearbox's aren't. Some electric cars do have gearbox's, some don't - it depends on the performance/weight and so on. Do not confuse motor torque with wheel torque - all of these are geared in some way.

 

[SwissMountainLeader]

IDK but if fitting a new chain. Regardless of mech cage. The combination of long chsinstays (29er Eebs I'm looking at you), a wide range cassette and suspension (chain growth) means many Eebs need a longer chain than what comes packaged (often just 116links)

You were spot on, the manufacturer told me that they fit chains from a reel basically. The LBS took a 116 link and added some links joined by two quick links which is all about what they had in stock but I’m not wildly impressed. I don't reckon it was moving well over the smaller cogs at all. My feeling is that LBS may have gone one link too many maybe as well. I’ve managed to get a couple of 138 link chains so I’ll swap onto one of them, the full 116 will go onto my analogue bike.