Turbo Vado 2 4.0 or 5.0 or 6.0?

[mcdenny]

Digging deeper into the rider power / motor power topic, using the Specialized support info linked in Allan's post above:

Since the motor produces a maximum of 300 watts at the pedal crankshaft at an 80 cadence,
20/100 means each rider watt is matched by (300/520) 0.58 motor watts
50/100. .............0.78 motor watts
60/100 ..............0.94 motor watts. motor power approximately equals rider power.
70/100...............1.12 motor watts
100/100..............3.53 motor watts. You + 3.5!

 

[Jeremy McCreary]

Thanks Jeremy. I'm an engineer too and appreciate your very detailed posts on how the specialized motor controller works.

My curiosity has to do with this: Lets say I'm riding in ECO (20/20) at maybe 12 mph at saturation. If I want to go faster it's all me. But if ECO is 20/100 all else being equal, if I want to go faster the motor will still be helping me (You, only faster, right). m Is my understanding correct?

Correct. Below saturation, motor power Pm depends on assist mode E/M only via E, and above saturation, only via M.

Since E = M = 20 in the 20/20 case, you'd necessarily saturate at rider power Pr = P1 = 139W. Motor power would be

Pm = B Pr (E / 100) = 64W,

where boost B = 2.3 for your motor. Total power at the crank would then be Pc = Pr + Pm = 203W, which buys ground speed Vg = 12 mph in this example.

At assist 20/100, Pm would still be 64W at Pr = P1 since E = 20 hadn't changed. But saturation's now pushed out to Prs = P1 (M / E) = 695W. So pushing Pr above P1 would definitely get you more Pm, Pc, and Vg.

For example, at Pr = P1 + 100W = 239W, you'd still be far below Prs. Then Pm = 110W and Pc = 249W, which would definitely get you above 12 mph under the same conditions.

 

[Jeremy McCreary]

Digging deeper into the rider power / motor power topic, using the Specialized support info linked in Allan's post above:


View attachment 205046

Since the motor produces a maximum of 300 watts at the pedal crankshaft at an 80 cadence,
20/100 means each rider watt is matched by (300/520) 0.58 motor watts
50/100. .............0.78 motor watts
60/100 ..............0.94 motor watts. motor power approximately equals rider power.
70/100...............1.12 motor watts
100/100..............3.53 motor watts. You + 3.5!

I like this way of looking at it!