Swapping Shimano disc brake calipers

Are there any obstacles to swapping Shimano GRX calipers to some MTB ones? Different flow rates etc

Got a new gravel bike with 12 speed GRX. Don’t like it. Want to swap that kit to the older Ti road bike which has post mounts and take the post mount SRAM to the gravel bike. Adaptors to do that are easy but flat onto post doesn’t work without adaptors that need 20mmm bigger disc. Hence new calipers. Some XT or something maybe.

I swapped Deore levers and calipers on my MTB last week as the brake hose is routed through the frame. There was minimal fluid leak, and it was easy. I still had to bleed the brakes afterwards but you might not even have to do that if you’re not touching the levers.

I’ve just left the old Deore calipers and new GRX brifters with a bike mechanic mate to fit to my gravel bike, to replace a non hydro set up as my frame isn’t post mount..

The only barrier I see is if it’s internal routing and you have to pay £3 for a Shimano barb and olive

I know lots of things cost a lot more but the price of Shimano olives irks me, as does the fact that you can’t get olives without barbs.

Shimano olives are available without barbs – part no 8H2 0400.

what’s up with the GRX? Love mine!

a. Shimano. Don’t like the shifting with the brake levers

b. 12 speed is proving to get through chains and they are not cheap

c. Rear mech is some how just fussy. Been brought up with nice old bomb proof Campag record and even 11 speed SRAM rival seems simple compared with this GRX.

b above will be less concern on the road bike.

As long as you have the correct hose fittings, any Shimano lever will work with any Shimano caliper as far as I know.

Shimano should all be compatible. Also they don’t even need to be Shimano. Aiui Magura and Clarks calipers will also fit, possibly others.

GRX are inline at the caliper, XT are banjo fitting, but apart from that should be fine. Just about to do the same.

My SLX spec chains lasted 300 miles. I switched to a waxed  XTR spec 9100 and did not manage to wear one out in over 3000 miles.

Hmm. Trouble is , I am too tight to risk an XTR chain.

XTR chains are undoubtedly worth it – get plenty mileage on MTB and Gravel.

Odd about the finicky rear mech – I haven’t found that at all.

Xtra chains are only 40 quid at Biketart. Much better corrosion resistance too.

Shimano mtb calipers work fine with Shimano hydro road levers, Been using post mount Deore calipers for years on mine and they work brilliantly. You will be limited to minimum 160mm rotor though, if that’s a problem.