Will a roadie mech ...
 

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[Closed] Will a roadie mech work with a 32t cassette?

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Either short or medium cage, an E-cookie for the first correct answer. 🙂


 
Posted : 10/01/2011 5:13 pm
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Dunno, but I'll be interested to find out, as I've got one sat here to go on my cross bike. I bought a long cage Deore mech to go with it.


 
Posted : 10/01/2011 5:15 pm
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short no, medium maybe, depends on the mech.....


 
Posted : 10/01/2011 5:15 pm
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yes,

you may have to switch the jockey wheels from 11t to 10t like i did,

i run a dura-ace with a 11-32 sram xx cassette no problems,


 
Posted : 10/01/2011 5:15 pm
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All medium length will work.

Short cage won't work as they can't handle the larger rings


 
Posted : 10/01/2011 5:17 pm
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So a medium will work without changing the jockey wheels?


 
Posted : 10/01/2011 5:19 pm
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to give us a better idea it would help to know what your running chainring and casette wise,


 
Posted : 10/01/2011 5:20 pm
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So a medium will work without changing the jockey wheels?

Assuming the block and mech are for the same number of cogs then yes.


 
Posted : 10/01/2011 5:20 pm
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Yes. Most road mechs are the same as a short MTB mechs and as long as you don't ride cross gears it'll work fine.


 
Posted : 10/01/2011 5:21 pm
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dirty is that a medium or short dura-ace?
I use a short cage dura ace (recommended up to 27t by the big S) with standard jockey wheels and can only just squeeze a 11-28 slx in there.


 
Posted : 10/01/2011 5:24 pm
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Will be using a single 36t up front and 11-32t out back.


 
Posted : 10/01/2011 5:26 pm
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short cage di2 dura-ace - swapped out the 11t jockey wheels to 10t kcnc ones, works perfect with 11-32 xx cassette


 
Posted : 10/01/2011 5:26 pm
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Will be using a single 36t up front and 11-32t out back.

medium will bolt straight on, shortcage will work with 10t jockey wheels,


 
Posted : 10/01/2011 5:29 pm
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I run 1x10 on the cx bike.38t up front and a sram 11-32 out back with an Ultegra short cage rear mech-wind in the b-tension screw and jobs a good un.


 
Posted : 10/01/2011 5:32 pm
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...Ultegra short cage ...

Thats not a short cage road mech then


 
Posted : 10/01/2011 5:40 pm
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Thats not a short cage road mech then
?

Most Road mech are designed for max 27 but will go 32 at a push but I'd guess the jockey wheel might wear a little. Bang on an XT or look at SRAM Apex.


 
Posted : 10/01/2011 5:51 pm
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I reckon Shimano road rear mechs are only rated up to 28 cogs.

Some campy ones do go up to 30...not sure on sram...other than I've an idea sram don't do long cage road rear mechs

Ring/email Madison for shimano...Fishers for sram..... and find out for sure (possibly for sure!!! depends which plonker you get etc)


 
Posted : 10/01/2011 11:08 pm
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Are some of you confusing gear capacity with the size of mech that it will run with? A mech capacity of 28 means that the difference between the small and large sprockets (say 28 minus 11 gives 17) plus the difference between the chainset rings (say 50 - 34 gives 16) so a mech with a 28 capacity wouldn't work. Unless you avoided changing to big ring/big sprocket.

The other issue is the b-tension scenario. A road mech may have the correct capacity but not the available clearance to work with a 32 tooth ring sprocket.


 
Posted : 10/01/2011 11:15 pm
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I reckon Shimano road rear mechs are only rated up to 28 cogs.

27t - unless you dont believe the specs, and adjust the b-tension or swap out the jockey wheels for 10t

sram red can be run with 32t as stock

Are some of you confusing gear capacity with the size of mech that it will run with?

no, a short cage road rear mech will never work with above a 32t rear cog even if the front cog is 1t


 
Posted : 10/01/2011 11:19 pm
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have a look at the font of all cycle knowledge, Sheldon Brown. You should find the info you need on his wonderful website. Won't necessarily be product specific but it will give you the knowledge of what parameters you need to be considering.


 
Posted : 10/01/2011 11:20 pm
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show me how you can get the short cage of the road rear mech not to foul the cassette cog of larger than a 32t


 
Posted : 10/01/2011 11:26 pm
 dobo
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according to the above, wind in the b screw and change out your 11t for a 10t jockey. i've not tried this though and cant confirm it works...


 
Posted : 10/01/2011 11:29 pm
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What a lot of misinformation (I shouldn't be surprised really).

Most road mechs are the same as a short MTB mechs

No they're not. The cage length might be the same, but the angle of the parallelogram is different - and that's the bit which is important when determining how big a cog you can use. The parallelogram angle is also the same for both short and long cage road mechs, so both should cope equally well (or badly) with a 32t cog.

I don't disbelieve at all the reports of people getting it to work - the trouble is it's well outside spec. so not at all guaranteed, in addition to which the b-screw and 10t pulley bodges both work to move the mech further away from the little cogs, thus making shifting worse down that end of the block. It does depend on your frame - no way I could get a 32t cog to work with a road mech on my cx bike.

So the correct answer is it might, but if it does the shifting is likely to be worse than with a short cage MTB mech - why don't you just use one of those?


 
Posted : 10/01/2011 11:42 pm
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as some people have correctly stated above mech cage length determines the overall capacity of the mech to tension and take up different chain slack...

this is why 3x9 and 3x10 mtb set have generally have a long chain as the amount of excess chain to tension varies greatly with the different gear ratios combos

max sprocket size is a function of the mech parallelogram (ish) action...

obviously for max efficieny this arc should be suited to the arc of the cassette cluster... road mechs are suited better to cassettes with small changes in sprocket size whereas touring/mtb mechs are suited to managing a wide change in sprocket sizes...

if you have a wide range cassette say 11-32 or 11-36 etc and also do not require a lot of chain slack to be taken up as you are running a single chain ring or two closely spaced chainrings on a double then you would be best using a short or med cage from a mtb groupo..

not saying you can not get other components to work, but best shifting from parts designed for the job.

you could of course if you have the road mech already just fit it and try..


 
Posted : 11/01/2011 9:47 am

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