My brother built this bike 5+ years ago. 70cc Athena, 21mm Dellorto, Estoril, stock crank.
I got it last year with a couple thousands miles on that stock crank. It was left at Motomatic for a couple years and was used as a loner bike. When I got it put a couple hundred miles on it until the small end started to go. I could feel it about to let go, so I ripped it apart and put a new crank in it.
Going from the stock crank to a stuffed roller was night and day difference. 18×36 gearing was not enough, I was out pulling two speed Gila’s, but on the down side only revving to 9.5k. Well I got bored pretty quick so the other night I threw together a new motor.
There are only a few rules at the shop. First and more importantly is “Gilardoni or die”.
So a couple hours later this was done.
Conveniently had a Tomos Simo laying around. So tossed that on.
First start vid. Pretty good bottom for 16×36 and a Simo. Have not topped it out yet, but it just started pulling super hard when I hit 50. Will update when I top it out, I expect mid-high 60’s.