Originally Posted by
hokiefyd
I think I've read elsewhere that all Shimano flat bar hydraulic brake levers are compatible with each other. Is this correct?
I think BH59 is the basic hose, right? BH90 is fully compatible, if you change the whole thing out? I guess one would need olives and nipples (and possibly nuts) for BH90 as well (a "full" conversion)?
Yes, drop bar levers as well.
Same outer diameter, different barb due to different inner diameter, same olive and nut. One barb is yellow and the other is silver. Correction: BH90 uses a thinner bore for a stiffer brake feel, BH59 uses a thinner wall (bigger bore) for a spongier feel. They are interchangeable; just use the proper hardware.