road 2×10 derailleur with shimano 2×10 shifters?

does it work?

Possibly (or possibly not) have all the bits for a flat bar CX type thing

Depends on your defenition of work.

I mean, the cables will fit, the levers will lever and the mech will move.

Without a chain you’ll only notice smooth movement without any problems at all so arguably they’ll work fine. But a chain won’t.

does it work?

No, you’ll need Shimano flat bar road 2 x 10 shifters

Front might work as Shimano front mechs are very forgiving to different shifters. Rear wont index. Just get a cheap 10 speed shimano mtb mech.

You want a 9-speed mech to use with 10-speed road shifters.

Useful reference: http://blog.artscyclery.com/science-behind-the-magic/science-behind-the-magic-drivetrain-compatibility/

Can confirm that the other half ran a 9-speed XT mech with 10 speed 105 shifters on her CX/Gravel/Commute bike and all worked happily (apart from the lack of a screw adjuster, easily dealt with with a Jagwire inline barrel adjuster).

But the OP isn’t using road shifters @toby

But the OP isn’t using road shifters @toby

Sorry, don’t know how I managed to misread that and conclude he was trying to do what I’d done.

Ignore me, but you may still find the ratio charts in the link useful

As per Mr Barnes and also depends which road 10spd for the road flat bar shifters.

Tiagra 4700 10spd shifter and rear mech is a subtly different cable pull to older 105 10 spd – so you need the matching flat bar road shifter.

You can get cable pull converters so you can mix road and MTB shifters and mechs

.http://www.jtekengineering.com/shiftmate/shiftmate-compatibility-charts-choices/

Shiftmate 6 is the one you want. Cheaper than buying flat bar road shifters but probably more than buying an MTB mech.

You just need road flat bar shifters

Like these assuming Tiagra 4700 mech

But as Mick said they changed the pull ratio on 10 speed. So the shifters will need to match the correct generation mechs

Oops

https://www.chainreactioncycles.com/mobile/shimano-tiagra-4700-2x10sp-flat-bar-shifter-set/rp-prod137775

I recently used 10 speed xt shifters with a 105 triple road . They are different pull ratios but when installing the cable into the FD you have to install it looser to compensate for the pull ratio difference.

And if you have to use flat bar shifters go for 4600 tiagra as the 4700 is a different pull ratio than all other shimano stuff.