Am I right in thinking that STi shifters and bar end shifters will be compatable with a MTB rear mech, but NOT compatable with a front mech???

it’s not as simple as that.

sram will be fine
shimano Fr mechs shouldn’t but can be made to work – but you can get a special mech any way.
rear mechs 9 is fine, 10 speed STi needs a 9 speed rr mech. 11speed ??

bar end shifters will be fine – fronts aren’t indexed.

Presumably you could get the older style shimano bar end shifters and use them on friction mode so they will work with any mech?

10 speed STi needs a 9 speed rr mech

Ooooh, is that right ?
I use RR on mine because it’s intuitively sensible but didn’t realise it had to be

I’ve got 9 speed Tiagra STIs with a Deore 9 speed rear mech. Works a treat.

I bought new 10 speed Dura ace shifters for a new, mtb, build and they didn’t work. It’s because I was using a fancy new 10 speed XT clutch mech rear mech. Shifting just did not work no matter how much fiddling.

I was previously using, older 8 speed dura ace shifters, with a normal 8 speed mech. They work just fine, indexed and everything. Front mech worked well with a 2 ring shifting. That wasn’t indexed though, quite useful sometimes having the ability to trim the front mech.

Yep, Shimano 10 speed roadie STIs work nice with 9 speed MTB rear mechs, and a roadie or CX front mech. It’s what all the cool cats on gravel racers old gits on tourers have been riding the last couple of years.

10 speed shimano mtb went to “dyna-sys” which uses different cable pull to 10 speed road, hence the 10spd mtb rr mechs operate on a different ratio. 10 speed shimano brifters should work fine with 9sp mechs, as the mech parallelograms share the same geometry, although I believe shimano claim a higher level of precision with the 10spd stuff.

Also google “Shimergo” to blow your mind – IIRC, the premise is basically that you can use any of the campag ergopower shifters with a shimano rr mech, on a shimano cassette (i think), provided you match the shifter with a 1-speed-less mech and live with having a redundant click eg: 10 spd ergopower shifter + 9speed shimano mech + 9 speed shimano cassette.

There is also something about creating different mech ratios by clamping the gear cable on the wrong side of the pinch bolt on the derailleur, but I don’t remember what the point of doing so was….

just looked and using the wrong side of the pinch bolt is called “hubbub” and both concepts are discussed in detail here:

http://www.ctc.org.uk/cyclists-library/components/transmission-gears/derailleur-gears/shimergo

when you use the term “rr”, you’re meaning something other than rapid-rise, are you ??

Yeah, sorry. Wasn’t familiar with that one – I just meant rear

😳

Me too.

Fr mechs at the front, Rr mechs at the back!!

Been fat and old but spending my summer hols riding in the Pyrenees my road bike and my cross bike both have 9 speed shimano mechs coupled with 105 10 speed STIs with a 10 speed 36 tooth rear cassette. The XT I had on my road bike definitely isn’t rapid rise.

The XT I had on my road bike definitely isn’t rapid rise

should be – they work great IMO (big lever for faster on each side and little levers for easier)