Now I must confess to not having known exactly what an SBach is other than a large scale aerobat I looked it up and noticed and correct me if I am wrong but it appears the aileron hinge goes all the way to the wingtip and this is a good thing as it makes for convienent mass balance attachment. While normally I would prefer to put the balance somewhere closer to the middle of aileron span but that's not a hugh consideration.

This type of tip makes it quite simple to make a tip plate on the aileron to carry the balance weight forward

John