The Shimano master cylinder bore tends to ovalize, thanks to the lack of surface treatment and the off-center push on the piston by the ServoWave mechanism. Sometimes you would also find deep scratches in the MC wall after just a few months, because the piston gets so mangled by the SW link it scores the inner bore. Then the seals aren't able to hold the oil anymore, and the dreaded wandering bite point appears.
If Shimano would start anodizing the MC **after** machining it, as SRAM/Formula/Hope/etc do, their brake levers would be much more longevous.
Sept. 28, 2020, 9:31 a.m. - Luix
The Shimano master cylinder bore tends to ovalize, thanks to the lack of surface treatment and the off-center push on the piston by the ServoWave mechanism. Sometimes you would also find deep scratches in the MC wall after just a few months, because the piston gets so mangled by the SW link it scores the inner bore. Then the seals aren't able to hold the oil anymore, and the dreaded wandering bite point appears. If Shimano would start anodizing the MC **after** machining it, as SRAM/Formula/Hope/etc do, their brake levers would be much more longevous.