Originally Posted by Trevor98

It's takes some work to replace hollow axles with solid ones. You have to remove everything from the axle, replace the hollow axle and then adjust the whole thing so it turns smoothly. Its more complicated than simply repacking or replacing the bearings as every thing in the system must be reset. The reason that the fixed/SS guys like solid axles is that they require really tight mounting of the rear wheel in horizontal drop-outs or track ends to resist movement when they apply back pressure to the pedals. On a newer road bike with vertical drop-outs movement is way less of a real concern.