I have had the Synergy E7 TT now for a few years, still going well so updated with a new head and its basilcally the SE version now, I changed the main gears last year.
I had to change the spur gear after I broke some teeth bench testing (dont ask!).
Received a new gear yesterday and it was impossible to mount on the hub, I measured just 0.2mm smaller inside diameter, i would have had to use unreasonable force to get it on which would probably crack the gear.
Anyway, wasn't defeated, I mounted the hub on an old main shaft with a jesus bolt and placed in a pillar drill.
At slow speed I switched on and used a file to gently shave off a little aluminium until it fitted perfectly, problem solved.
Another point, I got my new head from Experience RC, no blade grip arms, balls or screws came with it. Photo shows it, is that normal??