13.65s @ 85 mph is quite good. The lighter ZF8.5 helps it get a small ET even with a relatively low trap speed.
Some relatively comparable 1/4 mile
electric records from NEDRA:
DMC/F, "TRON" 128V twin AC, 9.835 @ 139.29 mph
DMC/G, "TRON" 93V, 11.693 @ 104.53 mph
MPC/F, tiger eboxer 106V AC, 14.291 @ 90.58 mph
Quick conversion from 1/4 mile to 1/8 mile shows about 8.7s. Here's 1/8 mile times:
DMC/G, Silver Bullitt 96V, 6.756 @ 96.47 mph
DMC/F, "TRON" 106V, 6.913 @ 100.71 mph
SMC/G, Juiced II 96V, 10.195 @ 64.67 mph
PMC/H, E-Boxer 72V, 11.73 @ 56.26 mph
DMC is a drag-specific bike. PMC = production MC, MPC = modified production bike. NEDRA has a HUGE array of classes; the 2013 Zeros would probably be PMC/F.
For reference to the gas world, a 500cc gas bike will typically be around 13 to 13.5 seconds in the quarter mile. Faster than most cars on the road.