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As title really, do double specific mechs such as this one http://www.chainreactioncycles.com/Models.aspx?ModelID=83158 have a smaller cage than a triple mech?
I've just tried setting up the front double with a 32/24 and can not bring the cage low enough before it hits the chain stay. If I try to index things with the mech as low as I can get away with then it either dumps the chain off onto the crank arm or won't shift back to the granny. The lumps and bumps inside the cage just won't line up right.
So do the 2x mechs have a smaller/shorter cage and will allow me to bring the mech lower or should I just go 1x10 now and save the messing!
I had the same on a c456. I set the mech height to an imaginary outer ring such that the lumps on the mech were in the right place.
Tried that but I'm not winning right now...something for tomorrow I think had enough fettling right now.
Rdl
Yes they do the shimano slx ones do anyway.
Its back to basics for me in these situations, isolate the issue as much as possible. Wind limit screws completely out, set the mech height such that the chain in the smaller chainring runs under the lump in the mech cage, add tension until it shifts right, set limit screws to stop it throwing the chain.
Cheers Tricky I'll keep it in mind as an option.
Daveh I'll have a go tomorrow now had enough!
Yes, double specific mechs have a smaller cage, and aren't that expensive so are the best option if you're set on a double.
However, a triple with the limit screw wound in will still work fine (ask yourself - if it shifted well between granny & middle before, why would it be any different if I just don't shift into the big ring anymore?), but [u]don't[/u] lower it as that [u]will[/u] stuff up the shifting, as the shifting ramps & gates will no longer be aligned with where the rings are!
Yes, a triple mech looks silly sticking up there when there's no big ring, but if that bothers you then see first sentence above...
If you do swap, it's also worth noting that there are two different types of double front mechs, the SLX you've pointed out is for a triple minus outer ring, the XT is for a double specific design, neither will work as well on the other system.
Would probably just grab the SLX tbh as was only intending to go 2x10 until it wore out then go 1x10 anyway. May just strip it off now and sell the bits as fitted/unused.
Will have a play later and check the bits as others have said first but leaning towards just swapping now, should break even after selling rings and mech.
I've got an SLX triple converted to 2x9,I had all kinds of trouble with the 3x9 mech that was on there so switched to an XT double mech. I think it's actually 10 speed but it works perfectly. And yes, it has a smaller cage so you can get it in the right position.
What Coatsey said he knows his stuff 😉
If you do swap, it's also worth noting that there are two different types of double front mechs, the SLX you've pointed out is for a triple minus outer ring, the XT is for a double specific design, neither will work as well on the other system.
If I remember correctly, in 9 speed Shimano only did a double FD in SLX, as they only offered a double specific chainset in SLX - the M665. But in 10 speed there's double FDs in SLX and XT. So what's the difference between the 10 speed SLX and XT 2x FDs that makes one a double specific design and not the other?
So what's the difference between the 10 speed SLX and XT 2x FDs that makes one a double specific design and not the other?
Well when I asked the LBS which would be better out of the 10spd 2x SLX or XT he said the SLX as well. The only thing I can see is that the XT is for a 48.5 chain line whereas the SLX is for a 50.
Be curious to know more myself.
The only thing I can see is that the XT is for a 48.5 chain line whereas the SLX is for a 50
Not so. The chainline of the XT double cranks (M785) and the SLX double cranks (M675) are both 48.5.
So, Coatsey, please explain...
it's also worth noting that there are two different types of double front mechs, the SLX you've pointed out is for a triple minus outer ring, the XT is for a double specific design, neither will work as well on the other system.
Genuinely want to know if I'm missing something here?
Was going of this tbh...
SLX 2x10 mech listed as 50mm chain line...
http://www.chainreactioncycles.com/Models.aspx?ModelID=83158 /p>
XT 2x10 mech listed as 48.8mm chain line...
http://www.chainreactioncycles.com/Models.aspx?ModelID=69484
Not sure on cranks, I'm personally using XT M770/771 with a 50mm chain line.
Have stuck a single ring on for now but like you still curious to know.
CRCs description of that SLX is wrong - apart from having the chainline incorrect, they've listed a "top-middle" capacity, which only 3x mechs have.
Not surprised, there's a bewieldering array of Shimano FDs around at the moment that it can get confusing!
No, what you need is a German to get the description right - [url= http://www.bike-components.de/products/info/p33967_SLX-Umwerfer-FD-M675---FD-M676-2--10-fach-Modell-2013-.html?xtcr=9&xtmcl= ]M675 FD[/url]
Shimano agree with zee Germans! http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/mountain/slx/product.-code-FD-M675-E2.-type-.fd_mountain.html
E-type as no details listed for the top swing, can't see them being different though.
The plot thickens then, come on someone, put us out of our misery 🙂
Simple explanation of my previous post is that each mech is designed to work on a different size set of rings, the converted triple usually being around the 22/32t size, the double 28-38t.
Simple explanation of my previous post is that each mech is designed to work on a different size set of rings, the converted triple usually being around the 22/32t size, the double 28-38t.
The specs of the M675 SLX double FD are - max ring size: 38/40, capacity: 14T, Chainline: 48.8.
The specs of the M785 XT double are - max ring size: 38/44, capacity: 14T, chainline: 48.8
Neither are 'designed' to work with a converted triple which has a chainline of 50 and a ring size of 32. Maybe the SLX will work slightly better with a 32 ring as it's designed for a max ring of 40, versus the XT's 44 - is that what you're suggesting?
Slightly crossed lines, was talking of my previous experiences which appear to have involved an M665 double (designed for a 36/22my mistake), not an M675. Sorry for any confusion caused, but they definitely don't cross over very well 🙂
Ah, yes, the M665. Shimano's first attempt at a double specific MTB crank IIRC. The chainline was the same as the M660 triple, and so the M665 FD was indeed a perfect solution for triples converted to doubles.
That was all in the dim and distant days of 9 speed tho' and now Shimano don't offer a double and bash in their lineup (much is the pity), and the 10sp SLX and XT double groupsets are so similar that the components are pretty much interchangeable.
So, back to the OP, I guess the conclusion is that your old 3x FD will work if you just leave it where it was, or if you want to go to a double specific FD and you're 9sp there's only one choice - the FD-M665, but if you're ten speed either the FD-M675 or FD-M785 will do the job.
Phew! Glad we got that one sorted out...