Viewing 16 posts - 1 through 16 (of 16 total)
  • Rear Mech – which?
  • FunkyDunc
    Free Member

    Out riding my 2012 10 speed XT Giant Anthem a few weeks back the rear mech snapped (god knows why I was just on a flat wide track) anyhow its knackered.

    So its time for a new one. Is it straight forward XT or is SLX just as good? Also I assume I need long cage?

    Ta

    simondbarnes
    Full Member

    The SLX M7000 rear mechs seem pretty good. Fitted one to my mtb recently (along with an M7000 shifter)

    Northwind
    Full Member

    SLX is fine tbh, the jockeys ime aren’t quite as good but they still last well and you can get replacements for £10 if you need to. Mostly I find mechs die when I smash them off a thing so it’s not worth stressing over

    Cage length depends on your exact setup

    darrenspink
    Free Member

    Im a zee mech person because of its low profile. FR version works with 10 or 11 speed with a 34 up front.

    FunkyDunc
    Free Member

    OK I’ve been holding out for the ‘Black Friday’ deals, and as it stands 10 speed XT has gone up in price at all retailers 😆

    Will 11 speed XT mech work with 10 speed drivetrain? Or am I better waiting for Black Friday ‘sales’ to finish, and getting 10 speed XT then when they come back down in price?

    Ta

    martinhutch
    Full Member

    I think I saw SLX long cage on offer with CRC for a reasonable wedge in the last week or so.

    http://www.chainreactioncycles.com/shimano-slx-m7000-10-speed-rear-derailleur/rp-prod148232?gs=1&utm_source=google&utm_term=&utm_campaign=Chain+Reaction-UK-PLA-PLA-All-DT-SE-Shopping+QLB+Product+Desktop&utm_medium=base&utm_content=mkwid|sdllV6np0_dc|pcrid|161850334074|pkw||pmt||prd|540636UK

    Medium is pretty cheap too.

    FunkyDunc
    Free Member

    That’s pretty good, but XT quite a bit lighter.

    Still struggling to find out if you can run 11 speed mech on 10 speed?

    Yak
    Full Member

    Still struggling to find out if you can run 11 speed mech on 10 speed?

    http://singletrackworld.com/forum/topic/1×10-bodgers
    It appears to be a yes. Not tried it myself, but if it improves 1×10 then i’ll do it.

    poah
    Free Member

    pull ratios are different between 11 and 10 speed mechs.

    FunkyDunc
    Free Member

    If you read the thread up there though it says the pull ratio is determined by the lever not the mech. Makes sense too, a mech is just a fancy spring

    Think I will go for XT 11 speed from Merlin

    martinhutch
    Full Member

    That does seem to be a good price. Tempted to get one myself in case I go to an 11-46 cassette, as I’m pretty sure my old XT will draw the line at that.

    superfli
    Free Member

    Yes 11 works fine with 10 speed shifter. I thought about it and as the mech is only a spring loaded device to go from a-b, as long as the distance it can move is the same and the upper jockey will clear the largest sprocket (b screw can move it enough), then it should work fine. The shifter controls how much it moves/how much cable is pulled.

    I bought an 11 speed xt mech a while ago for my 10. It’s been perfect with my 11-40 setup

    reggiegasket
    Free Member

    as long as the distance it can move is the same

    The shifter controls how much it moves/how much cable is pulled

    The shifter controls how much cable is pulled, that’s true, but the mech ratio controls how this is translated into lateral movement of the jockey wheel, and this isn’t the same for 10 and 11spd mechs, so your statement isn’t quite true…

    it’s all here http://blog.artscyclery.com/science-behind-the-magic/science-behind-the-magic-drivetrain-compatibility/

    If you run a 10 shifter with a 11 mech then it’ll undershift slightly, (which may well still be okay in reality). Cable pull on a 10 shifter is 3.4 and the mech ratio on a 11 mech is 1.1, so the mech will move 3.4 x 1.1 = 3.74mm per shift, which is slightly less than the sprocket pitch for a 10spd cassette of 3.95mm. In my experience Shimano (factory) setups overshift a tad, so undershifting may actually improve things.

    Yak
    Full Member

    If you run a 10 shifter with a 11 mech then it’ll undershift slightly, (which may well still be okay in reality). Cable pull on a 10 shifter is 3.4 and the mech ratio on a 11 mech is 1.1, so the mech will move 3.4 x 1.1 = 3.74mm per shift, which is slightly less than the sprocket pitch for a 10spd cassette of 3.95mm. In my experience Shimano (factory) setups overshift a tad, so undershifting may actually improve things.

    So, if i’m getting this right, and you set the mech to be bang-on in the middle of the cassette, then the worst case is 5x(3.95-3.74mm) = 1.05mm short at one end of the cassette. This will be noticeable, won’t it? 😕

    superfli
    Free Member

    I suppose although the shifter is pulling the same amount of cable, it doesn’t necessarily mean the mech is moving that amount, which is what I didn’t take into account. Fortunately it’s not noticeable and in fact it works better than the 10s mech as I’m using a larger than 36 sprocket 🙂

    reggiegasket
    Free Member

    So, if i’m getting this right, and you set the mech to be bang-on in the middle of the cassette, then the worst case is 5x(3.95-3.74mm) = 1.05mm short at one end of the cassette. This will be noticeable, won’t it?

    You do have it right. According to the number sit undershifts by 0.2mm each shift, which is 1mm over 5 shifts (or 6 sprockets).

    But it doesn’t appear to be a problem in reality, given the anecdotal reports that it works okay..

    I’ve not done the 10shifter-11mech thing myself so I can’t confirm it either way.

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