Anyone ever installed D's on thier chair? How do they attach to the hub or axle? Do they come with thier own axles? I am in the process of getting a new chair, TiLite Tr, and I would like to put a set of D's on it. I am looking at puting titanium axles on it, but if D's come with a different axle set up I wont pay for the titanium axles. I have had my Quickie GP for about 15 years now and I have replaced everything but the frame many times.