Well, Id say get a motorcycle, except you can't pedal one. You'd be surprised though, how good exercise a longer ride is on a motorcycle or larger scooter. Does wonders for the core strength, and exercises the legs more than you might think. 80 miles a day on a motorcycle is actually quite a workout, but not a cardio type one.
Your plan has two main problems. One is that 35 mph cruise speeds take about 1500-2000w, So you are looking at carrying two very large 1000wh batteries on the bike. This just about requires a cargo bike, or at the very least a stronger touring bike frame. Put 30 pounds of battery weight, plus another 20 or so of motor on most bikes, and they will start to wobble above 30 mph. This wobble gets worse if you induce wobble by pedaling at higher speeds, even the faux pedaling you might be doing once going that fast because its hard to gear a bike to pedal up real power at 35 mph. This is not a 100 m sprint, you need really high gearing to cruise 35 mph and pedal hard.
So there you are, not really able to pedal like you are thinking you will, because of the limitations of most frames side to side stiffness.
These problems are not unsolvable, but in general, you are not going to buy this bike off the rack. Many of us have built bikes that easily cruise 40 mph without pedaling, but generally for shorter distances at that speed, and carrying 15 pounds of battery, often inside the triangle of the frame. Or, if you can learn to weld, then you can build anything you want. This bike I built for example, easily carried 50 pounds of batteries, with 30 pounds of it in the frame trays in front and behind the seatposts. The battery trays framework added the sideways frame stiffness needed to carry huge battery weight. And by the way, I can't weld for shit. But its easy with a cheap wire feed welder.
The other approach is build for less speed. 28 mph cruise is easily done by most bikes, requiring only 52 tooth front gearing. Then you need only select a frame that can carry some heavy panniers or a very sturdy rack without too much wobble, so you can carry two batteries of 48v 15 ah. That would be for the full 40 miles, about 1500wh.
Another good approach is to start out aiming a bit lower on the distance too. Get a sturdy bike rack for a car, and commute the last 20 miles of the trip, leaving the car someplace halfway. Get on the commute, see what its like, and what it will cost to build that dream bike. Starting out with a bike able to do 28 mph top speed and cruise 25 mph most of the ride is easy. It will require only a single 48v 15 ah battery for 20 miles. 40 miles a day riding will get you all the exercise you need.
You will save about 25 cents a mile on the bike part of the commute, so about 10 bucks into your pocket every single day you ride 40 miles of commute, vs driving it. This will pay for the bike quick enough, and then put more money in your budget to improve it, like a stronger, possibly home built frame for the whole commute.
You CAN do the whole commute eventually, but my advice is to do half of it now, cheaper and easier. Then with some experience, you will better understand what improvements are worth the money and which are not. You might continue do only part of the distance, but keep increasing it bit by bit, as you make your bike more able to carry big weights, and see what effect increasing the weight has on the battery needs. It gets a bit exponential at some point, 5 mph more speed means a ton more battery, and then that added battery weight slows you down, and decreases your efficiency.
This is why the bar is set about where it is for most commuter e bikes, about 25 mph cruise, about 1000 watt hours of battery. This is the sweet spot, where weight and cost and efficiency meet the best. Above that size battery, you start to get out of commuter bikes, and into long distance touring e bikes, that ride 15-20 mph, and can go 80 miles per charge. Commute is harder, you have to get there in reasonable time, at reasonable cost.
Cheapest by far, is a sub 500cc motorcycle. Seriously, about half the cost of ebikes if you buy used moto's. My 400 cc Suzuki comes in at 12 cents a mile, while the very very cheapest e bike I ever ran came in about 25 cents a mile. Car about 50 cents on up depending on the cost of the car.
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Hi All,
