Is it that once you get more and more film on the spool, it gets harder and harder to wind?
I've had that problem with 24/36 and with 120. Best advice I ever read was to run a pencil around the grooves in the plastic reel, then the film just slips on so much easier...
(also, one really good thing about 135 is that you can get it started in the light for maybe 5cm or so, then do the rest in the dark room/bag.