BH59 expands a bit when the internal hydraulic pressure is high because it has inadequate wall stiffness.jwiegand wrote: ↑Thu Mar 10, 2022 3:20 pmWhat's the difference on the hoses?StiffWeenies wrote: ↑Wed Mar 09, 2022 6:43 pmEither way, if anyone is still on BH59 hoses and L02A/L03A/J02A/J03A pads, now is the time to upgrade to BH90 hoses and L05A/J05A pads for massively improved braking performance. Perhaps RT-MT900 rotors as well for good measure.robbosmans wrote: ↑Wed Mar 09, 2022 6:33 pmAh yes was looking at one of those my bad, new ones are backordered
BH90 keep the same outer diameter but make smaller hole for hydraulic fluid inside. That result in thicker wall better resisting expansion force, at cost of more fluid flow resistance because of the smaller pipe.
Hayes, Magura and many other manufacturers instead of making hole smaller for wall to be thicker, they simply enlarge hydraulic hose outer diameter. Or you could do Jagwire's approach of just use better material, aka Kevlar hose.