The True Top Speed: should we be concealing it?

[Cameron Newland]

I've got a production ebike that has a listed top speed (28 mph) that is, shall we say, "conservative".

I haven't been going all over town telling people about my S-pedelec's true top speed because I've realized that it might be better for the industry if the entire e-bike community were to publicly maintain that all of our ebikes topped out at 20 or 25mph, which might draw less negative attention from federal/state/local transportation lawmakers and from law enforcement, and might help to keep ebike sales rising at a rapid clip due to less interference from safety-zealot regulators.

I know there has been a lot of discussion over the years about listing the true range of ebikes, because manufacturers tend to overstate range significantly, so that might put us ebike consumers in the camp that might want more accurate facts about ebikes coming from manufacturers, but when it comes to top speed, do we really want to know the true top speed, or would it be better for everyone if we were kept in the dark and given vague or inaccurate top speeds, as is the case with my ebike?

Also, does your ebike go faster than its listed top speed? Do you even want it to?

 

[PowerMe]

My PAS bike tops out at 20mph as advertised. If one is in boost mode and pedaling hard one can go faster, but the motor is helping out only to 20mph.

 

[pxpaulx]

My PAS bike tops out at 20mph as advertised. If one is in boost mode and pedaling hard one can go faster, but the motor is helping out only to 20mph.

My easy motion neo xtrem goes up to 27 with pedal assist...Not that I can keep up beyond about 24 or so!

 

[stevenast]

Mine cuts out in the high 19's, like 19.6, 19.8.

It is painfully legal lol

 

[PowerMe]

My easy motion neo xtrem goes up to 27 with pedal assist...Not that I can keep up beyond about 24 or so!

Yours is rated for 25mph on PAS. Mine is rated for 20.

 

[Mike Smith]

My Diamondback Trace EXC will easily do 27-28 mph on flat roads in pedal assist even with my 260lb load but I personally find that to fast for me in the urban settings in which I ride. I'm happy that they listed this and it was on the review here so I know what I was getting into from the start. There are times when I want to and feel comfortable going fast and am glad I know the full capabilities of the bike. Yes, the manufacturers should provide realistic info on top speed of their ebikes, imho.

 

[PowerMe]

My Diamondback Trace EXC will easily do 27-28 mph on flat roads in pedal assist

Well that's good because that's exactly as designed & advertised, since it's a speed pedelec bike.

 

[Reddy Kilowatt]

My Optibike Pioneer Allroad takes me up to a few tenths about 21 mph on throttle only. It's reportedly 20 mph. It's mid-drive motor is also nominally rated at 500 watts but can actually consume about 54o or so when I am pouring the coal to it.
Allen

 

[Cameron Newland]

I can consistently hit 32 mph, and sometimes 35mph (depending on wind conditions) on flat pavement in the highest PAS mode, but that's pedaling hard (say, 100-250 watts of human power). The only time when I can't go any faster than 28mph (the top speed as listed in the manufacturer's specs) is when I'm facing a 10+mph headwind. Mostly, I cruise at 24-30, though. And I can even reach 30 mph when in the second-to-highest PAS mode, but again, that's when pedaling hard.

I'm curious to know if my bike is putting out more than 500W at these speeds. I assume that it is, because it's a 500W hub motor that can likely put out 700w+ at peak. Since I don't have a Cycle Analyst, I'll never know.

 

[George S.]

I can consistently hit 32 mph, and sometimes 35mph (depending on wind conditions) on flat pavement in the highest PAS mode, but that's pedaling hard (say, 100-250 watts of human power). The only time when I can't go any faster than 28mph (the top speed as listed in the manufacturer's specs) is when I'm facing a 10+mph headwind. Mostly, I cruise at 24-30, though. And I can even reach 30 mph when in the second-to-highest PAS mode, but again, that's when pedaling hard.

I'm curious to know if my bike is putting out more than 500W at these speeds. I assume that it is, because it's a 500W hub motor that can likely put out 700w+ at peak. Since I don't have a Cycle Analyst, I'll never know.

Educated guesses for a hybrid, upright type bike:

If you pedal at 12 mph, that's about 110 watts (at 17 mph 200 + watts)

To go 28 mph requires about 600 watts. So 600 - 110 = 490 watts from motor

The battery has to put out more watts than 490, since motors are not totally efficient

 

[Cameron Newland]

Thanks for the figures, George.

I figure that the motor is putting out ~750W and I'm adding 200-250W (keep in mind that I can't keep up that kind of output for more than a minute or so), resulting in my 34mph speed on flat pavement. With the terrible aerodynamics of a bicycle, I figure it'd take about 1000W to hit 34mph. I think some of the 1000W kits can go a little faster, but that's at peak (not nominal) power, so they're probably putting out 1400W+.

 

[Marty]

If your bike goes too fast it can cause you real trouble if and when they start enforcing the laws.