I live in the USA and if I want to get rid of my car I would need to be able to cover 70 miles round trip with moderate exercise in a reasonable amount of time. I think if I could cruise at 35MPH (56 KMH) that would be enough to make the switch.
It may be stupid, but I’d like to try to avoid an electric motorcycle - those need insurance, registration fees, real parking spaces, and a special license. Also, I enjoy getting some activity while riding. FWIW I’m not worried about legality, but I do plan to stay off bike paths/sidewalks to avoid endangering pedestrians and other cyclists.
My idea so far is to start with a gravel bike frame for aerodynamics, efficiency, and sturdiness in case of a pothole or rogue curb. From there I’m thinking about a 1500w hub motor, dual batteries, higher gears, bigger brakes, and permanent lights for visibility. Also a good helmet of course, crashing at that speed can be pretty bad.
Has anyone done something like this and had it go well/poorly? Anything I’m clearly missing in my plan? Also feel free to tell me if I’m an idiot, but I already know that bit.
I’ll start with the public policy spiel: the fastest class 3 electric bikes max out at 45 kph (28 mph), meant to be just below where mopeds max out at 30 mph, then after that, other, faster two wheeled machines that require licensure and insurance. Proceed with care with the advice you receive. At the very least, please don’t tailgate cyclists or pass them aggressively or too closely, and don’t ride on bike paths. OHV tracks will probably be more fun anyway.
Ok, with that out of the way, there are some technical challenges you’ll face. For reference, a dual battery Bikonit MD750 ebike with the speed governor raised to its maximum 60 kph will run at full speed to empty in approximately 32-35 kilometers (20-22 miles). Allegedly.
That particular electric bike has a 750 W motor and a pair of 700 Wh battery packs, each weighing 4 kg, give or take. So that’s 1.4 kWh for 35 kilometers, if we’re being optimistic.
Your build seeks to attain 56 kilometers one way, but let’s round up to 70 km for reserve capacity. If you’re able to charge at work, then that puts your energy requirement at some 3 kWh, which is a lot of battery. This will also be 16 kg (35 lbs) on its own, which has implications on your bike’s frame and suspension.
Now, if you ran slower than max speed, the requirements drop substantially. The same MD750 above is good for 80-100 km when run at only 30-40 kph. But it sounds like you’re looking for a one hour commute each way.
In that case, I would suggest you reexamine the electric motorbike, as they have the advantage of being prebuilt, already have the necessary capacity, take standard motorbike accessories, and have a much taller max speed, if you so choose. Some even have removable batteries, to bring it into your workplace and charge indoors.
Price of an electric motorbike, of course, may be higher than building your own electric bicycle. But the amount of battery cells in question is substantial and much care in design would be needed. The finished product would likely also be somewhat conspicuous, versus a stock electric motorbike. But this may be a function of whether your workplace has secure indoor parking.
I love seeing what people will build and ride on two wheels, and many will necessarily push the envelope on what’s appropriate around their area. Proceed with care.
Really appreciate your thorough answer! I’ll definitely think about an electric motorcycle. IMO if I’m going to go through licensing, I might as well get something that goes full car speed.
I think you’re right that battery capacity would be the biggest issue building out an ebike. That said, a big frame triangle can fit a lot of cells. Something like 3000Wh could probably get the job done. If I could get the bike aerodynamic enough to cruise on a 750w motor, then max range would be 3000/750=4 hours or 140 miles. Obviously won’t hit that in real world conditions, but 70 would be possible.
I terms of legality and ethics, I totally agree about treating cyclists and pedestrians with respect - on my current ebike I keep it under 18MPH on bike paths and slow to pass others at a safe speed. My vision for this bike is more rural back roads near my house which are mostly empty but have an occasional car passing by. I’m not a big fan of laws generally. On that front I’ll probably run a cracked controller with a toggle so if I get pulled over I can put it back in legal mode with a keypad sequence. Slap some aliexpress “250 watt” and “class 2” stickers on it and trust that the local cops are few and otherwise occupied. Where I live folks rip illegal dirt bikes and ATVs on public roads with impunity so I can’t imagine this being a big problem.
If people are ripping around on dirt bikes already a Surron or similar night be a good bet. The only issue is then you lose it on the ability to pedal. There are similar bikes that also have vin numbers if you actually wanted to go legal at some point but dirt bikes aren’t street legal without extras anyway and it sounds like enforcement is lax.
The electric unicycle idea is also pretty cool. They look to me like skiing but on the street. So you’d actually get exercise even if it’s working different muscles than a bicycle. But if you go that route you’ll need to go the extra mile on safety gear.
As someone else stated, 35mph the whole way is a lot on an ebike, even bringing that down to 30 extends the range a lot. There may be some road or gravel bike that has the range you’re looking for if your flexible on the speed. Those seem more fun imo, but the YouTube channel TailhappyTV has shown off ebikes that go 100 miles on a charge. I haven’t seen the speeds at which they go but in my opinion a long ride means more time to listen to audio books.
Either way good luck!
I’m wondering whether you would want to consider a mid-drive motor instead, if pursuing an ebike build. 750 W delivered at the hub, without the benefit of gearing, may only be marginal to attain your envisioned speed. But in a mid-drive configuration, 750 W should hold 50-60 kph without an issue. The reason for going higher power beyond that would be to improve the acceleration at those higher speeds, but if you’re planning for mostly back roads, then you won’t have the stop-and-go or slow-then-go scenarios that might warrant more power.
To reduce the power consumed, also make sure to consider the tires. Certainly, aerodynamic drag starts taking effect after 20 kph, but the rolling resistance of some of the fatbike or dirt bike style tires mounted on some ebikes can be serious sources of drag as well, when running at higher speeds.
In my case, my street-running ebike has too wide of tires, being 26x4.0, and I don’t have the option to go narrower because of the rim width. In future, I plan to build custom wheels that has a 220mm wide hub but a 45mm rim. This will look ridiculous, but it’ll let me take narrower tires that run higher pressures and have lower weight penalty from the anti-puncture layers. If you’re going to take an existing frame, pick one with narrower hub widths, tailored to the surface types you intend to ride on.
My “test” for rolling resistance is the speed I can attain with motor off, pedaling only at a leisurely pace. With my acoustic bike, 20 kph is easy with no heavy breathing or anything like that. With my ebike, it’s more like 10-12 kph. That doesn’t sound like a lot, but it has huge consequences at speed. Anything to get that pedal-only speed up will pay dividends at the top speed.
You want a vespa.
Vespas here need registration, insurance, etc. etc. That would solve the range issue though.
At 35mph, registration and insurance aren’t bad ideas.
Safety gear isn’t a bad idea, but registration and insurance don’t make sense to me - if I’m on a 100lb vehicle on a road where everyone else is in a 4000lb vehicle it doesn’t make sense why I would need liability coverage. And I’m not damaging the roads the way cars/trucks do so it doesn’t make any sense to me to pay anything to the state/country for registration.
I think the problem is that you’re looking for an e-bike with the specs of a motorcycle/vespa/moped, and those require a licence, registration, and insurance.
I remember seeing similar questions on e-scooter subreddits, where people would be asking about e-scooters to go 65mph with over 5000W of power, not realizing that most places restrict them to 500w or less, and a max speed of 15mph. LOL
I get that laws haven’t really caught up to all micromobility options, but this is something to keep in mind.
Depends on jurisdiction, yeah. Some places you don’t even need a license.
Yeah we need e-mopeds. In my state under 50cc doesn’t need a reg or license to ride on roads. Some of the spicier 49ccs can do 45-50mph. Electric equivalents would be nice, but I’m worried they will be difficult to fit weight and space wise on a bike frame. A used Puch or Moped frame would be better maybe.
I also live in a rural sidewalk-less town and am thinking of building something similar, but I haven’t done any work on power requirements or range yet. Let us know how it works out.
You want long range, fast, and electric. pick two.
If you can stand to go slower, plenty of bikes can get you to 25. 35 is kinda outside of bicycle speed territory.
That’s fair, but what is the limiting factor? Frame geometry? Power? I downhill mountain bike and regularly hit 45 on open sections. I think if the motor could keep up the bike would be fine.
I think if the motor could keep up the bike would be fine.
You are not quite correct. The more powerful a bike’s motor is, the beefier the frame and wheels have to be, or it will literally bend or break when you apply too much torque. You also need a strong suspension, thicker tires, and (most important) solid disc brakes. So most bikes that are very fast and powerful end up looking more like small motorcycles.
There are some relatively “stealthy” ebikes that go as fast as you want, however:
But they ain’t cheap. The beefy parts and frame add more money to the final cost than the motor, I would guess.
You could also carry a second battery if you want to double your range (assuming you get one with an easily removable battery).
The biggest is probably just efficiency, both with aerodynamics and how motors work (from a quick search, rolling resistance seems to go up with speed, too). Faster is more work thus less range. That and battery (or just total) weight.
Personally I went with the cheapest, smallest, and lightest ebike I could find that still has gears. Aside from trails, it’s easier to lift/store and transport for 1-way trips. I definitely couldn’t go 70 miles, 35 miles is a maybe (I have gone ~22 miles before as someone relatively not in shape, also battery indicator on my bike seems to be unhelpfully cautious/lacking resolution).
I feel like paying 2x+ what I paid isn’t worth it either (especially when they have worse aspects) but cheap is probably not for everybody, at very least because it’s a 250w motor so it doesn’t go very fast (particularly on its own, but gears help). Haven’t ridden it in months because my local trail won’t be finished with maintenance until next year (I have no navigation and I don’t want to deal with pulling into ditches).
Whatever bike it is, you ride 35mph on a,bike path, expect a stick in your spokes.
Yeah definitely no bike paths unless you keep it under like 18mph imo. This would be for rural roads.
You could check out electric unicycles. The specs on high end ones are getting pretty crazy these days. 50mph easily with ranges around 100 miles. The Veteran Sherman S is a good choice for long range street cruising. The Begode EX30 is another big, heavy, extremely fast long range wheel.
Take a look at Pedago’ s Ridge Rider
I own this bike, and i have not regretted the purchase at all. Its range is pretty decent, 55mi I think. The bike has a software speed limiter which prevents the motor assist above 20 or 25mph depending on the model you get; but there is a community of folks that have some hacks around it (though I haven’t done this myself).
One of they key defining features of this bike is the throttle control; you can have pedal assist turned on and then also use the throttle on the handlebar to have the motor do all the work.
Awesome bike! I have an E-mountain bike and really enjoy it. For this application, I’m not sure if the mountain bike design will give me enough efficiency to hit the range I need. Maybe with narrower street tires and mostly locking out the suspension, but that removes most of the mountain bike advantages IMO.
You don’t need a bike, you need a great public transport system. Great means service every 5 minutes all day, every day. System means the entire city is covered with great transfers to express routes that move fast to close to where you want to be. It can be done, and would be cheaper than a car for everyone in your city in the long run, but it will also be expensive to get there. Good luck.
You’re not wrong but public transit here sucks. Every weekend I go to a friend’s house - by car it is 1 hour every time. By train it is somewhere between 2.5 and 3 hours depending on delays. Public transport (even when poorly implemented) offers a great way to get in/out of medium to large cities, but isn’t really ideal for trips from one rural area outside the city to another. What would be much more convenient would be if I could bring an ebike on the train with me. Most of the distance on this trip is covered by a 1h train ride, and it’s just the busses on either end which are slow and unreliable. Unfortunately they don’t allow electric bikes at all, and normal bikes are only allowed during certain hours.
i have an ariel rider kepler, it seems like it checks your boxes with the speed and power requirements, and it does have amazing range but i’m not sure how the range would hold up if you’re constantly keeping the motor at 100% going super fast all the time. if you could manage to charge it when you get your destination, it might be good for 35 miles. or you could add another battery, i think ive seen youtube videos with the kepler getting a battery mod.
Ariel riders look pretty great! How is it to pedal? Geometry wise it looks like it would be hard to get much power out of pedaling it. I would seriously think about buying a used rider to steal the drive train out of though, seems like they have a nice powerful platform and lots of customization options on the aftermarket.
it is pretty difficult to pedal on its own, the kepler is a 70lb bike with its battery. but i can still feel my legs doing work when i set the assist low and i can get it going on flat ground when i turn off the motor.
My bother in law has a Juiced Rip Current S, with the performance upgrade it does 30mph on throttle, it’ll probably go faster with pedal assist. I can test it later if you want.
I’ll need to check what model it is, but it’s probably the highest power one.
Technically not street legal, but nobody is going enforce that. Probably.
To guarantee the range you’d probably need a spare battery.
You can also put a rack on it to carry stuff and the spare battery.
Anything that goes over 28mph is no longer an ebike in the US and would need to be registered as some sort of vehicle. Sorry.
You could get an e-moped or scooter maybe, especially if you don’t care about legality but keep in mind at higher speeds you’d want to wear better protective gear rated for those speeds (DOT rated in the US).
Also, keep in mind, motorcyclists are often referred to as organ donors because they die a lot, so if you ride be careful as fuck.
Legally speaking sure. I’ve never seen that enforced though so I wouldn’t be particularly concerned about the legality of it.
Yeah, probably some sort of moped or scooter or something
