Mixing Shimano MTB + road parts…

No doubt it has been discussed before but if anyone can shine some light on this it’d be very helpful!!

I want to mix 10 speed road shifters (triple 105s) with a MTB rear mech for a touring set up.
Front mech, and front chainset is 105 10 speed too as well as chain.

But… I’ve read that nowdays I can’t use a new Shimano 10 speed MTB rear mech, I need a 9 speed (Cos of the indexing/shift ratio) – No probs there, got some old 9 speed rear mechs.

Issue is… do I need a MTB cassette for this set up which is want i.e a 11-34 for touring use, rather than a road cassette. So to clarify – 105 10 spd shifters + MTB 10 speed cassette + 9 Spd MTB rear mech!

Ta in advance!

I think the CTC fora have whole sections devoted to this sort of thing – might be worth a look there?

Got it in one!

As long as the rear mech has the right capacity for the 10speed cassette and front ring combo you are going to run it all should work ok. Someone with more experience here might correct me on that.

CTC will be your friend here. This is always cropping up.

What the OP suggested does work. I run that combination (with Ultegra shifters) on my VN Amazon.

So to clarify – 105 10 spd shifters + MTB 10 speed cassette + 9 Spd MTB rear mech!

Yeh – got pretty much exactly that on 2 bikes (one with road stis and one with ultegra flat bar shifters)

Was thinking of tourifying my Audax bike, which currently has a 34 x 25 lowest gear on a 105 10 speed groupset

I understand that 10 speed road shifters, road chain and road cassette work with a 9 speed mtb rear mech. Is a 10 speed mtb cassette the same width as a 10 speed road cassette? Can the 9 speed mtb mech work on an otherwise 10 speed road drivetrain if the cassette is mtb 10 speed? Just asking cos I’ve been told the indexing is different on 10 speed road and mtb shifters, which would suggest they are different widths. Confused of STW….

Same width apparently, must be down to something else.

I had a 9-speed XT on my 10-speed 105. Eh, 10-speed 105 chain I think and no idea at all what the cassette is, SLX probably, not convinced it makes any difference (got a road cassette on the dh bike after all)

Oh and on that note, XT rear mech for sale 😉

Probably won’t help in this case (as you’ve got a bunch of parts already) but SRAM WiFLi road groupset kits give you an 11-32 cassette and a mid-cage mech.

I’ve run 10spd road shifters with a 9spd MTB mech a few times in the past and there is sometimes a tendency for the mech to overshift slightly, which you can get round by altering the cable position at the clamp on the rear mech. It wasn’t a one off either, so keep an eye out for that.

You can also run a 10spd 11-32 SRAM road cassette by the way.

Thanks all. Downshep – As I now understand it, the MTB 9 speed rear mech is actually able to cover the spread of cogs on a 10 speed MTB cassette as they are the same size – so long as you’ve a long cage rear mech. Makes sense as a 10 speed chain is thinner so I assume the cogs themselves are too?

The road shifters wont work with a new MTB 10 speed rear mech as the mech has a different ratio of indexing. So it’s the rear mech causing the issue not the shifter or cassette.

All complicated especially as the set up I’m trying to achieve was pretty much standard on touring and tandem bikes and some liked to use 9 speed MTB rear mechs on CX bikes. Maybe the big S just want us to buy their touring XT range.

Seems odd they are the same width but don’t index the same. Ho hum, will look at a SRAM 32 and a Tiagra 30. Cheers

Read about this in the ctc mag a while back. The issue is with shadow+ rear mechs as they have changed the pull ratio for mtb stuff so 10spd mtb mechs need 10spd mtb shifters. it also means the 10spd shadow mechs are not backward compatible to 9spd nor are they 10spd road friendly.

The rest of the components – allowing for mech capacities etc – are to same spacings/dimensions.

Actually Shimano road 10 speed cassettes are 1mm narrower than MTB ones. Close enough that it’ll work just fine, but not exactly the same.

The above advice still stands – 9 speed MTB mech with 10 speed shifters though.

So now I have a 10 speed Shimano Deore cassette – a dyna-sys one. Bit concerned that it may not work with the 9 speed shifter as it’s dyna-sys.

Perhaps I should have got a sram one?! 🙄

Ta-da!

105 triple shifters, XT 771 (9 speed)chainset, 105 triple front mech, SRAM 11-36 10 speed cassette, 9 speed XT shadow rear mech, KMC X10-L chain.

So now I have a 10 speed Shimano Deore cassette – a dyna-sys one. Bit concerned that it may not work with the 9 speed shifter as it’s dyna-sys.

Perhaps I should have got a sram one?!

10s cassette and 9s mech with a 10 Road shifter will work, Njee is right that road cassettes are 1mm narrower, but set up for the middle of the cassette and thats only 0.5mm out at each end (even less as the last gear is defined by the limit screw, not the cable, so they might be perfect, but the next gear in will be 0.4mm out).

Thanks, the video on Shimano’s site makes out the Dyna-sys cassette has smaller spacing between cogs but I find this hard to believe. Guess I will find out for sure but I’m tempted to switch it for a Sram just incase.

Shimano MTB 10 speed cassette will work fine, as will a SRAM one. So to repeat what others have already said –

10 speed road lever
10 speed MTB cassette
9 speed MTB mech

Robert is your father’s brother!