MTB shifters with road crankset / deraileurs

[devocean]

I'm trying to upgrade my dad's bike for him. He's got a tripple chain ring with 8 spd cassette but with MTB shifters.

 

I'm wondering if I buy 3 x 10 MTB gears, and a Tiagra 2 x 10 crankset with 10 speed cassette, would that work?

 

Also, the current bottom bracket is a 'Tien Hsin BB-7420'. Would a normal English threaded BB fit that? (The frame is a Scott Roadster s2)

 

Any advice would be welcome thanks!

[David Marshall]

The easy part is the bb.  The frame will take any English threaded bb.  The rest is not as simple and you are going to have to research each and every part in detail.  For example the 4700 Tiagra FD will not work with MTB shifters but the 4600 should. I would suggest that you buy 10 speed flat bar Taigra road shifters with the rest of the Tiagra components.  (You will need the whole groupset including the chain, derailleurs, crank and cassette).  Brake levers are the usual problem on flat bar road bikes as linear pull MTB brakes are not compatible with road callipers.   You need the very old V brake levers or designated road levers.  Hopefully the levers that you have are suitable.

[devocean]

The easy part is the bb.  The frame will take any English threaded bb.  The rest is not as simple and you are going to have to research each and every part in detail.  For example the 4700 Tiagra FD will not work with MTB shifters but the 4600 should. I would suggest that you buy 10 speed flat bar Taigra road shifters with the rest of the Tiagra components.  (You will need the whole groupset including the chain, derailleurs, crank and cassette).  Brake levers are the usual problem on flat bar road bikes as linear pull MTB brakes are not compatible with road callipers.   You need the very old V brake levers or designated road levers.  Hopefully the levers that you have are suitable.

 

Thanks for the advice. His bike currently has a mtb handle bar, with mtb brakes and gear levers but with normal road (sora) brake callipers. Seems to be working fine for him. Basically would just like to upgrade his drive chain for him. He'd be happy with a 2 x 10 road crankset, so just whether 3x10 mtb shifters would work with a 2 x 10 crankset