How much assist am I getting in mph?

[edgechaser]

So I love biking. I am in the market for an ebike. To cut to the chase other than output in Watts , Can anyone tell me how much assist in mph can I get from the electric motor vs just pedaling with the motor turned off? Assume flat ground and no wind , with a 200 pound rider. Its great reading stats of how long a battery lasts . I am thinking of buying the 2017 specialized turbo vado 6.0. Their marketing website says capable of reaching 28 mph but how much input do I have to do to get there and maintain that speed?

 

[Ravi Kempaiah]

So I love biking. I am in the market for an ebike. To cut to the chase other than output in Watts , Can anyone tell me how much assist in mph can I get from the electric motor vs just pedaling with the motor turned off? Assume flat ground and no wind , with a 200 pound rider. Its great reading stats of how long a battery lasts . I am thinking of buying the 2017 specialized turbo vado 6.0. Their marketing website says capable of reaching 28 mph but how much input do I have to do to get there and maintain that speed?

A test ride would give you more insight than any number of responses here.
Maintaining 28mph on any Brose motor powered bike requires substantial input.

 

[PaulGee]

Based on my short test drive of that bike ... I would guess I was putting in about a third less effort compared to a 30 lb regular hybrid bike I ride that is to maintain 25 mph .. forget maintaining 28 mph for very long in my shape except for relatively short distances.

 

[JoePah]

Having done 25 mph on my Stromer and 25 mph on my single speed pedal bike, there is a huge difference in effort... However, a lot more power is needed on that eBike because of the higher rolling resistance of the tires (l.p. 1.75" w tires vs 23 mm, h.p. race tires), and much higher rotational mass of a hub motor wheel. and it weighs 30 lbs more.

I would say it will feel like you're pedaling 18 mph and the bike will give you another 10 mph. That extra 10 mph from the motor to reach 28 mph is a lot more power than you're providing..

 

[JRA]

I ride a bike that will maintain 28+ on level ground and am 195.

While it is possible to get to 28 just by putting a Vado, or the equivalent EU-US spec class III bike, in turbo getting it in the highest gear ratio and pedaling to activate the PAS I don't see how one could maintain that speed for very long given that their peak power output is at the most 700 or so watts. And at that you are going to be burning wh's much like as represented above. Few that I have seen have a final drive ratio high enough also that won't have both the motor and your legs rpm's maxed out. My setup does however allowing for a comfortable cadence at speed while adding as much wattage of my own as desired.

In comparison there is a big difference between going 20 mph and 28 in regards to pushing though the air and how much power that takes. This is from a more typical ride

Both were done with active but no sweat pedaling in similar terrain although the longer ride had one decent climb, another wh drain. Almost twice the distance and half the wh/mi at the slower average pace is a substantial gain and why most of my riding is done averaging in the high teens to lower 20mph.

Although motorcycles get decent gas mileage I have always thought they should do better given their power to weight ratio, but now I think it is because of the poor aero dynamics of the human form at speeds over 25mph.

 

[Trail Cruiser]

Basing on my experience on 3 ebikes, it needs at least 300 watts plus your own pedal power to reach 28 MPH.

Ebike #1, 500 watt direct hub drive (2015 Izip Dash). I keep the assist level in 2 (~ 300-ish watts?) out of 4 and sometimes 3 (~400 watts?) to keep my speed above 20 mph and then hit 26-28 mph on some slight down hills.

Ebike #2, 350 watt mid drive (2015 Raleigh Tekoa). I keep the assist level in 3 (~ 300-ish watts?) out of 4 to keep my speed above 20 mph and also hit 26-28 mph on some slight down hills.

Ebike #3, 1,000 watt mid drive (BBSHD 2015 Giant Stance 2). I keep the assist level in 3 (I programmed PAS-3 at 350 watts ) to keep my speed above 20 mph. In this case, I can sustain longer high speed rides of 28 mph due to the higher wattage and I don't have range anxiety on this ebike since it also has a much higher battery capacity.