Speed is a magnitude, a scalar quantity (i.e. 65 mph)
Velocity is a magnitude and direction, a vector quantity (i.e. 65 mph north)
Acceleration is the change in velocity over a unit of time
(1) Different rates of acceleration.
Given for the motorcycle:
Vi = 80 km/h
Vf = 90 km/h
Given for the bicycle
Vi = 0.0 km/h
Vf = 10 km/h
*IF* the time unit is the same (let's say 10 seconds), the actual value is the SAME for each, because the change in velocity was the same for each. 10 km/h over 10 seconds.
a = [ Vf - Vi ] / t
a = [ (90 km/h) - (80 km/h) ] / (360 h)
a = [ 10 km/h ] / (360 h)
a = 0.023 km/h^2
See, same thing, bicycle or motorcycle, change is 10 km/h, over the same time period gives the same value.
Incidentally, you should usually use meters per second (m/s) and seconds (s) not hours and kilometers.