Fascinating brake hose question – BH90 Vs BH59

I’ve gathered some pre-owned Shimano kit to switch my GB to hydraulic brakes. The manual for the RS685 levers specifies BH59 hose and the BR7070 caliper manual says BH90.

The hoses look very slightly different bores but does it really matter? Can I just use BH90 hose and olives with the levers ? Will I die or suffer am oily explosion?

As long as the insert matches the bore size it works fine, so use the insert for the hose (olives are the same, but the inserts are or 2.1 or 2.3mm)

My rs505 levers are running bh90 hose no trouble.

The olives are the same, it’s the inserts which differ – bh90 uses the silver inserts.

The inserts must be the correct ones for the hose or you will have issues with leaking air/oil.

You can interchange the hoses so long as the inserts are correct for the hose in use.

The BH59 should leave a slower more progressive lever feel and the the BH90 should be sharper and bitier. Shouldn’t make any difference to final braking power I don’t think, just how it feels while delivering.

Great, thanks folks. I’ll get hosing 🙂

Reminds me, I need some more hose as mine is wearing through. Would you pick me some up while you’re at it, ta.