Dumb E-bike questions.
 

I bike commute to work 2-3 times per week. I've been thinking about getting a e-bike, alternating rides, and going 5 days a week. I know absolutley nothing about ebikes. Hopefully you all can answer a few basic questions I have.

1. If a e-bike says 18mph top speed. Is that all it will literally go? If I also pedal can it go faster? Or does pedalling only help extend the range? Will it go faster down hill? On my pedal commute I frequently get over 25mph, will a e-bike potentially go slower then I am used too?

2. I am assuming the speed and range are also effected by a riders weight? If the speed/range is tested for a 175 lb man, will it substantially change for someone over 200lbs?

I'm sure I'll have more questions coming along..

25mph on the flats? I'm impressed. If you're looking to add power to your legs, the right e-bike will take you over 30 mph!

If there's a top speed on an e-bike, that's the speed where the motor will cut out. Beyond that, it's all leg power. Of course, you can pedal at any speed and doing so will extend your range.

Electric bikes that are chain driven or where the hub has a freewheel will likely go downhill faster than regular bikes mainly because of the weight. If the hub doesn't have a freewheel, there will be a slight electromagnetic drag (cogging) not noticeable unless you're flying downhill.

I think the range will change significantly if you have a lot of hills to deal with.

ebike commuter
 

Hi, I do use an ebike for commuting, just started this spring. I went to the ebike because I pull a burley trailer with my daughter in it, and with an 11 mile commute and a lot of hills, I just couldn't manage it efficiently on a road bike. My feedback is this... it's a completely different riding experience. I'm finding I really enjoy it because I can zoom along at around 18-20 mph most of the way and arrive at work feeling like I've gotten some exercize but am not exhausted. That said, if I was in great shape from riding all the time anyway, and wasn't pulling a trailer with lots of hills and so on, I'd probably stick with the road bike. I guess the variables I'd look at are whether you really want a transportation alternative that gets you on a bike more often... saving gas, arriving at work with a smile, those kinds of quality of life things. Personally, I'm absolutely in love with my ebike; it's the answer to my commuting dilemma. Yes, ebikes will go as fast as you can pedal them. Most are fairly heavy I think (mine certainly is), so it's definitely not the same sensation as a road bike. It's funny, now when I go for a recreational ride on a road or mountain bike, I look longingly at the ebike, but once I'm pedaling, it's all fun...

My bike is pretty light weight coming in around 65lb and as long as the weight is distributed evenly its really not all that different aside from the going faster easier bit. If you are pedaling 25mph right now I would not recommend you get a x-mart e-bike or anything similar. The store bikes have a "max assisted speed" of 20MPH and will either not help you above 20 or actually cause drag above 20 because they don't have enough voltage to overcome the magnetic forces at work. You probably don't need that much assist so motor options for you are plentiful. BMC/pumas might be more then you need, crystalyte 4 series, 5 series or DC hub motors are all options, Wilderness energy makes a brushed and brushless kit that would also do well for you.

As for the weight question, http://www.kreuzotter.de/english/espeed.htm has a speed calculator that lets you put in all kinds of factors. You will notice that if you are on the flats, there isnt much difference from a 175lb rider to a 200lb rider. As you add hills in it starts to take effect and as you deal with stop and go it starts to take effect even more.

Be aware that many people are not fully truthful about ebike top speed and range. I can go a little over 35 km/her with my quality hub and with NiCad batteries my range is about 25 km. Into a head wind or up big hills and the speed and range drop considerably. That said, I can fly home down hills and with the wind at my back and barely use the assistance.

Having the hub on a quality donor bike means I can pedal home without assist if need be.

And that's the truth!

1 - of course not. 18mPH max is the electric assist. You can always pedal faster if the gearing allows it, and you can actually pedal fast enough. My bike's assist tops out at 38km/h (no speed limiter, motor RPM limited) and I often speed along at 42 km/h. I could go faster but I'll need to change the gearing.

2 - Weight will affect speed/range for sure. But more than speed is hill climbing ability. If you get a eBike with a powerful motor (500W) you should have enough reserve power to hit the bike's speed limit (20MPH). It'll just accelerate slower. My dad is 210lbs and he can easily hot 32km/h (20MPH) on his ebike.
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