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Deore derailleur on road bike

Wife rear derailleur has just gone belly up, I've a spare deore MTB derailleur M610 kicking about same speed, as a quick quick temporary fix would it fit onto 105 running gear?

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5 comments

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TheBillder | 3 years ago
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It's been 10 days now and I still can't think of a joke around "wife rear derailleur". Someone help out?

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fukawitribe | 3 years ago
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My first thought was no, it's not going to fly as Shimano 10-speed road and MTB drivetrains use different cable pull ratios (9 speed was OK), but might be close enough to work somewhat for some of the range perhaps.... normal answer is to use a JTek/Lindarets convertor but if Welsh boy has already tried it might be worth getting details from him about what works etc. 

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Welsh boy replied to fukawitribe | 3 years ago
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All i can remember is that I used a road rear mech on a mountain bike I put together for poppng to the shops and general running around.  I have mixed 9 and 10 speed kit regularly with no problem, the rear mech is dumb, it just moves a bit when the cable attached to it tells it to, the amount it moves is determined by the shifter so generally as long as your shifter and cassette are the same number of speeds then you will probably going to be ok.  Like I say, bolt it on and give it a try, a 10 minute job and if it doesnt work you are not going to damage anything.

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Welsh boy | 3 years ago
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You won't do any damage giving it a try. I have used a 105 mech with deore shifters in the past with no problem 

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NickJP replied to Welsh boy | 3 years ago
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The short answer is no, the M610 is a 10-speed MTB RD, and Shimano changed the pull ratio with 10-speed so that road and MTB components no longer used the same pull ratio. JTek engineering make a series of components called Shiftmate, which are placed inline in the gear cable, and change the pull ratio. Have a look at the compatibility chart here: http://www.jtekengineering.com/resources/shiftmate-compatibility/

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