IMHO...U have to do more fix gear man, looks like you are fast enough the issue is that u dont have power. I still can do 50+ km/h in a super short accelerated sprint using 53x17 but cant hold it for more than 5 to 7 secs, my difference is that I dont have power and im like 100 pounds overweight, sum to that maybe 150 miles during this year, obviously i have to suck Use me as an example ok?

Fix gear with maybe 48x20 or something similar just to start... mix with accelerations... blah blah, old style pre season little kids type of training. I wont go any deep because is pretty long to explain... stuff like that will get your legs fast. Sure others have other methods but preseason stuff to gain high cadence nothing like the stuff reg harris used to do.

Good luck


ps: "i thought that it was ideal to get less weight off the rear wheel so that pedaling is easier, is it not?".. is not because of that is because he needs to use everything he has to move 53x11, in a matter of fact the bike gets harder to handle and goes jumping here and there in their sprints.