Firstly when i pedal hop on to a wall and dont quite get on top my brake slips making the wheel roll backwards an falling off, is there anyway I can stop this happening? i.e certain way of grinding the rim etc, my brake is awesome going forward! iam using Heatsink yellows (cnc backings) water bled hs33, Try-all rim with a grind. Also can I buy rear Hope pro 2 hub shells anywhere? The 07 version. Thanks in advance James