GRX lever with PM calipers

Fancy a GRX groupset but my frame is post mount, has anyone used a shimano post mount caliper with a GRX lever successfully?

Yes, I’m using GRX levers with Hope RX4 callipers which are available in post-mount,

It’ll be fine.

I’m using GRX with some antique XT M775 calipers and it works great.

Cheer guys.

[post grab] been wondering similar as have a postmount frame/fork which I really like but would like to move on from HyRyds…anyone used these:

https://off.road.cc/content/news/shimano-quietly-launch-new-cheap-4-piston-brakes-deore-br-mt520-brake-2702

believe intended market is ebike…not got round to going thru tech stuff to check but believe shimano has more than one hose spec?

I’m just in the process of doing exactly this. Learn from my mistake: if you buy a lever without caliper, it almost certainly won’t come with the new style bolt that you need to connect the hose:

https://www.sjscycles.co.uk/brakes/shimano-smbh90-flange-connecting-bolt-m9-for-str8020-y8rd02000/

The hose that I bought to fit the XT PM caliper with a banjo connector at one end came with the old style bolt for the other.

Merlin had a good deal on GRX levers + flat mount calipers. You’re almost certainly better off buying that and flogging the FM ones as the cost of bolts + connectors quickly adds up.

shimano has more than one hose spec?

Yes, BH-59 and BH-90. The difference is only the inner diameter of the hose, so you need to make sure you use the right barb, but the olives are the same. BH-90 is newer and has a smaller barb. I think BH-90 is supposed to give a firmer feel, but I’ve not heard of any issues from using the “wrong” hose provided you use the right barb.

As above, there’s (at least) three types of connector in circulation. My understanding is:

• banjo used on MTB calipers
• straight with an M9 bolt, used on newer road/GRX calipers
• straight with an M8 bolt, used on everything else.

You’re almost certainly better off buying that and flogging the FM ones as the cost of bolts + connectors quickly adds up.

Hard disagree. All you need are a couple of the M9 bolts for £6 each. Good luck recouping that flogging 2nd hand calipers plus there’s the ballache of selling them to factor in. No way, Jose.

Its the Merlin deal is what has caught my eye but I have a complete set of Shimano BR-MT200 flat bar brakes with post mount calipers sat doing nothing that i picked up in a sale. Bonus being they have the screw on caliper fitting and not the banjo fitting. So hoping it will be as simple as just swapping the calipers over.

@pdw ref hoses and connectors great info cheers

Hard disagree.

Merlin is £349 for lever + hoses + FM calipers. Wiggle is £334 for a pair of 1x levers. Hoses £12-£16 each, bolts are £6 each (plus postage from SJS).

If you’ve got banjo calipers, you’d still need to buy hoses as I don’t think you can buy banjo connectors separately.

Annoyingly, the Merlin deal was announced pretty much the day after I’d placed orders across 3 different shops trying to get a better deal, and I’d have been happy to end up with a spare FM caliper ready for when the seals next fail on my other bike.

So hoping it will be as simple as just swapping the calipers over.

It should be, but you’ll need new olives for the caliper end as they come preconnected.

It would be nice if Shimano just supplied everything in J-Kit form

straight with an M9 bolt, used on newer road/GRX calipers

Too late to edit, but that should be newer road/GRX levers

@pdw I stand corrected, sir (or madam).

I recently bought a flat to post adapter for my new GRX from Spokeydokeybikes.

Bit pricey though.