Getting a bike on the center is a lot about the step down, less about lifting and pulling. If it's a little low, roll the back tire up on a couple feet of 1x6.
Now thats an idea, is a bit low to grab on the seat only, tried it with my right leg only on the C stand, hard... then all my weight with my left leg pull and grunt at the same time standin on that knob, seemed a bit easier...
Got to get used to it again , aint used dem muscles in a while...
vik...will try the plank.