Effect of rider weight on range and climb ability?

[Pastabatman]

How significantly does rider weight impact an electric bike's range and ability to climb?

As background, I am considering buying Easy Motion's Evo City Wave or Evo Jet. The Jet is 5.5 lbs lighter, but has a significantly better range (Jet is 35-55mi vs. City's 20-45mi), which is surprising since the bikes are otherwise almost identical. (The other significant difference is the City's 'upright relaxed' rider position vs the Jet's 'forward' position, which I imagine would have some impact on range as well, due to wind resistance.)

Anyhow, I got to wondering how much my own relatively light weight (137lbs) would impact performance. I have a steep grade (10% for a half mile) I'm considering for my commute to avoid busy streets, and wondering if it's even do-able with one of these Evo hub-drive bikes without getting sweaty and sending my heart rate into the red-zone.

 

[Pastabatman]

Court just informed me (in comments under the Evo City Wave review) that the estimated ranges for both bikes should be about 30-50mi (there was a copy error in the tables). In any case, I am still wondering about the impact of rider weight on overall performance.

 

[George S.]

Weight is much more of a detriment to climbing grades than it is to range. Climbing means lifting weight, so the more weight, the more energy it takes. Range is a function of speed and you are usually cruising. Once you get the weight up to speed, the impact is fairly low. The air resistance is what eats up the battery. Almost all ebikes are fairly upright.

You would have to test any model to see if it would climb that grade with a 'reasonable' amount of help. Anything over 8% is iffy because hub motors have limitations at slow speeds. If you added 200 watts, it would be a lot more doable than if you added 50 watts. Pedaling 17 mph on a flat (no assistance at all) is around 200 watts. It's not a lot of time to pedal fairly hard, if it was enough.

Given that many cycling apps now include grades and grade graphs for every part of the ride, it's too bad there is not more information about grade capabilities for the bikes. There is a website that will give you the grade between two points, but it is finicky trying to get just the grade.

http://veloroutes.org/hillgradecalculator/

 

[PowerMe]

Court just informed me (in comments under the Evo City Wave review) that the estimated ranges for both bikes should be about 30-50mi (there was a copy error in the tables). In any case, I am still wondering about the impact of rider weight on overall performance.

What's interesting is the range Court published (which is lower than what Easy Motion claims) happens to match *my* real-world results for my EVO Street. 30 miles is what Easy Motion claims as the minimum but that is close to the maximum of what my bike can do, at least with me on the bike, and using assist levels from Standard to Sport. If I use Boost a lot then the range is more like a maximum of 25 miles. If I could use Eco only then the range might be as much as 35 to 37 mi, but I'm not in good enough shape for that. My roads are comprised of grades from 1% to 5%.

 

[stevenast]

Anyhow, I got to wondering how much my own relatively light weight (137lbs) would impact performance. I have a steep grade (10% for a half mile) I'm considering for my commute to avoid busy streets, and wondering if it's even do-able with one of these Evo hub-drive bikes without getting sweaty and sending my heart rate into the red-zone.

Your lower weight is a definite plus, but as for your heart going into the red zone, a lot of that is going to depend on your own level of physical conditioning.

There's been a lot of debate on this forum about mid-drive vs hub-drive, but I think it's safe to say that a mid-drive system will handle that steep grade with ease ...of course the speed you're going up that hill will once again depend on your own physical conditioning.

 

[Pastabatman]

Thanks for the replies. I'm not concerned with speed, since it's a relatively short distance. I've sort of ruled out the mid drive for my first bike, due to cost, and I suspect options for mid drive will improve a lot in the next couple of years. Worst case scenario is I will have to take a little less-pleasant commute route traffic-wise.

I plan to rent a Pedego soon to try out my route before making a final decision on buying an e-bike at all. When I do, I'll also give the big hill a go, just to see.