Originally Posted by
shoota
It doesn't do anything.
What do you mean? It does cover the top opening of the caliper, so it seems like it would impede ingress of water and particulates, which should be a good thing since I don’t believe the Spyres have any seals for the balls/cam/piston which moves the pad.
If you’re saying that’s a non-issue, well perhaps; I don’t know because I have no experience with them, but I took apart one of my BB7 once— just once was enough! There are lot of bits in those things!— and they have outer and inner seals on the piston side which may have been a factor in why I never had to rebuild them in the 16 years I ran them. I mean I did the one, but mostly out of curiosity, not because the action was gritchy or grindy.