Since there were some unanswered questions in this thread, I thought I'd go through and answer a few of them. I've been playing with ebikes for a few years, and my current one is my "daily driver" for pretty much everything - commuting to work, running errands, bouncing around town, etc.
I'm running a custom ebike with a ~1300W geared rear hub motor in a 26" mountain bike frame and a 500WH LiFePO4 battery (~2x my normal daily usage). I've gone to a single large front chain ring as it's a dedicated ebike, and my solution to "The motor has failed and there's a hill" is "walk it if it's steep enough." I don't see a need for additional complexity for incredibly rarely used situations. The rear shifter is a twist grip on the left bar (it shifts "backwards" but you get used to it quickly).
I'm in the Seattle area, so hills are a bit brutal here. I *can* pedal bike to work, but the "showing up sweaty" thing and I don't get along, so the ebike it is (most of the time). It's now also faster to ebike than drive, so I really only drive to work once a month or less if I have a lot to carry or am dressed in a suit for whatever reason (it's rare enough that a bicycle suit carrier is not worth it).
I consume 25-30WH/mile (give or take - I don't have exact numbers, but this is about what I've determined based on range) under normal riding, so about an order of magnitude better than a Tesla or Leaf - you can, in fact, call them electron guzzlers. Depending on what you eat and how your power is generated, it can actually be lower carbon than a regular pedal bike.
I'm kinda curious as to how the range of the battery is affected by winter conditions. At 20 below how well do these things tend to work?
Somewhat poorly if the pack gets cold. Search for "[battery technology] temperature curve" and you'll see charts that show capacity/power dropping off quickly as it gets below freezing. I can certainly feel a difference in the winter (around 32F) vs the summer (70-80F) in power delivery.
However, the good news is that there are some easy enough solutions to the problem. One simple solution is to add additional pack capacity so that even a reduced temperature pack has enough range. Another is to, in the cold weather, keep the bike indoors (or at least the battery pack indoors) and insulate the carrying case. The pack will start out warm and it's internal heat generation while discharging will keep it warm enough for a normal range ride. Finally, you can buy battery heaters that run off the battery and keep it warm. This probably isn't worth it for a typical ebike use case unless you're riding 20-30 miles in the cold, since a well insulated pack will be perfectly fine if it starts out warmer.
On the plus side, if you have enough additional pack capacity, you could install heated grips or run heated gear in the winter (this is common for people who ride motorcycles year round). And, you can just pedal a bit harder in the winter to generate your own heat. :)
- Type of battery, lead or lithium. Both have advantages, depending on if you use your bicycle mainly for longer distances or for many short errands AND it depends on your climate. You also have hybrides and new li-on and 'all plastic' batteries that can resist temperatures up to +45 celsius and down to -40 celsius. But they are expensive and not easy to fix.
I respectfully disagree. There is no reason to use a lead acid battery on an ebike now. They're heavy, short lived, and dreadfully inefficient at higher discharge rates that are common for EVs (even ebikes). A lightweight lithium pack will outperform a lead acid pack in every metric, and the costs have come down enough that it's not even worth bothering with lead anymore.
There are a few different lithium battery types, though, and most ebikes use a standard lithium ion battery. This is typically good for a few hundred cycles before losing significant capacity. I'm actually a big fan of lithium iron phosphate (LiFePO4) batteries for ebikes. You need a physically larger pack for a given capacity, but they have a cycle life measured in thousands, are a bit safer (though it's not really a big issue anymore with a decently designed system), and, nicely, have a nearly constant voltage across their discharge cycle, so end-of-ride voltage (and power) is almost identical to start-of-ride voltage (and power). It's also a bit more expensive, but for a serious ebike build, the high cycle life means the total cost over the years is radically lower as they'll last almost indefinitely if cared for reasonably. And constant power throughout the discharge is a nice perk, though it does mean you won't have much warning before the batteries quit on you if you run the pack out.
The spokes kept breaking off.
This is, sadly, a common issue. The best option seems to be to get a motor/wheel assembly from a reputable ebike vendor. The lacing pattern is a bit different with a large motor than with a normal hub, and many motors are drilled for larger spokes than standard for bicycles. If you use the proper size spoke and a lacing pattern that works with the motor diameter, it's far less likely to be a problem. It's also a good idea to go with a heavy duty rear wheel if it's offered as an option. I've not regretted the extra money I've spent on getting heavy duty rear wheels, as they break spokes far less frequently. An ebike is typically going to be heavy, and run fast, so it puts a lot more stress into the wheels than typical bicycling duty. Combined with a heavy rider, you can easily overstress a lightweight wheel build and cause it to start failing.
I thought sol's comments in a different thread were right on.
[insert sol's comments about how ebikes are not hardcore enough and MMM is selling out]
I know plenty of folks who are a little older and a lot of out of shape, better to have an e-bike than no bike at all.
I've had this conversation numerous times, since I work on a team with a rather hardcore bicyclist.
My view is that it strongly depends on the situation, and an ebike is still radically better than a car.
If you're FIRE, potting around town on your own schedule, in good shape, and don't care if you're a bit sweaty, great - a regular muscle-bike is the best approach. If you work in an environment with showers, and don't mind getting to work hot, showering, cooling off, changing, etc, then a muscle-bike is also a great way to get around. However, not everyone is in that environment (or wants to spend the extra time in the morning showering/cooling off/etc). An electric bike allows you to, for example, use a good motor assist going to work so you can get to work cool, and pedal more on the way home when it doesn't matter as much.
An ebike is also a great solution if, for whatever reason, you're not able to fully power yourself around (hills being a common problem for many people). A surprising amount of interest in my ebike comes from older people who haven't cycled in years due to knee/hip trouble. In many cases, there's "that one hill" that they cannot comfortably deal with getting home, and a small motor assist would enable them to bike instead of driving. Not everyone lives in the flatlands, and I'm not one to tell a 60 year old to suck it up and get in better shape (though, if they're bicycling instead of driving, that happens anyway). Many of them didn't even know that electric bicycles were a thing. I have no idea how many have actually gone out and picked one up, but there are quite a few who now know, if they want to bike, there are options they can work with.
As my boss pointed out when I was arguing about carbon output between ebikes and pedal bikes, "FFS, you're both on bicycles and using a fraction the energy of a car to get around. You're not the problems!"
I think everyone would agree that an electric bike is a radically better transportation solution than a car. Going back and forth about bicycles vs ebikes is hair splitting way off on the end of the bell curve of transportation methods. Either way is radically cheaper and better for the environment and the person than a car.
The folks at endless-sphere.com have tons of advice and rides to share.
Endless Sphere is a slightly silly place, at times. There are far too many people interested in going way too fast on way too cheap a vehicle to do it safely. They will certainly help out for dirt cheap ebike ideas, but well executed, safe, reliable ebikes are a bit rare at times there.
The beauty of an electric assist is that it really eliminates a lot of excuses. And frankly, often those excuses are valid. I couldn't even ride my bike around my old neighborhood -- the hills literally made me sick to my stomach.
Yup. "Oh, it's too hot, I don't want to show up drenched in sweat" goes away as an excuse with a motor assist.
I think MMM is right -- easy electric kits (esp. ones like the Copenhagen wheel and the Flykly smart wheel) are potentially 'gateway' drugs for lots of people to get those bikes that are collecting dust in their garages and drive lots left.
I tentatively disagree, mostly because things like the Copenhagen Wheel have yet to actually be released. I'll have a better opinion on them once they're available, but from what I've seen, they're radically inferior to either an electric bike available now, or one you build.
The Copenhagen wheel is still vaporware, as far as I'm concerned. A few demos does not a viable product make.
The FlyKly is also mostly rubbish, IMO. A 250W motor is not worth sacrificing gearing on the rear for (it's only available as a single speed rear, as far as I can tell), it only works with rim brakes, and it's rather of expensive for what it is. You could put a 250W front wheel hilltopper kit on a bike for substantially less money and still keep your gearing.
The "fancy" ebike conversion wheels are limited in power, limited in range, and are mostly a set of compromises determined by "I'm going to fit everything in an unmaintainable wheel!" Build something with more traditional parts and you have a more powerful, longer range ebike that's easier to work on. I'm sorry, I don't feel the need to sync my ebike to my smartphone. I want a minimum of things to go wrong.
Bicycling is often faster than driving for me as I have my own personal lane while cars are stuck in traffic.
At least in Washington, ebikes can also use the bike lanes. :) I'd feel bad about blowing past people uphill, except I rarely see other people in the bike lanes anyway. But, yes, it's faster than driving for me as well. A car commute (in the evening) is typically 25-30 minutes for 5 miles, with a peak of 45 minutes one day. I can get home on my ebike in about 18 minutes, regardless of traffic (I suppose if it's really, really bad, I might take 20 minutes because of a few lights that stay against me longer).
The mid-drives are very efficient and also work well because they use your existing gearing. I've not heard anything bad about the Bafang either.
The mid-drive motors are certainly efficient at any speed, but I'm not entirely sold on them unless you need one (for a heavy cargo bike or heavy towing). Mostly, you're putting a LOT of power through a chain system that's not built for it, and this stretches the chain and wears the sprockets quickly. Replacing chains and sprockets adds up quickly, and at some point, a more powerful geared hub motor in the rear wheel is likely to be cheaper in the long run.
Anyway, sorry for the long reply. Hopefully it helps a few people. I'm happy to answer any other questions people have.