I've lived in different cities in Europe and Australia, and I noticed more and more the creation of bike lanes, and increases in bike commuters. Still, the number of eletric bikes in the streets is incredibly low. Although it can be said they are expensive (see related question), I cannot believe this is the only reason.
So I ask the experts: what is the biggest issue to bring them to the mainstream market?
I would add to the already existing answers some of the thoughts that come to me as a bike user.
For me using a bicycle is a mean to prevent getting out of shape. Using an electrical bike would be like going hiking with a car or elevator. This applies for a lot of my friends riding bikes.
Some of my colleagues complimented me on the fact that I exercise daily by riding to work. In the same register, I expect the opposite reaction for riding an electrical bike, as it would point the user out as a lazy/weak person, unwilling/unable to do any effort. Not saying it's true or right to be judged, but people often live by what others think about them (the coolness factor). you may get coolness points in the gadget section, but it's a different group of people that will compliment you on that. So it depends on where you want to position yourself.
A cheap bicycle is something you can easily toss in some corner when reaching a destination (edit: and of course diligently chain it up), without too much worry regarding theft. Can't do the same (with peace of mind) with an electrical bike.
Depending on where you live, using a cheap (second-hand, maybe) bicycle for two to three months already pays for the bike itself, by saving on transport costs. With an electrical bike, there is a steep initial investment, and the ROI is spread over a much longer term.
Electrical bikes are heavy and not so easy to maneuver in tight spaces where you need to carry them (like stairs). If they are light usually they are very expensive.
Finally there is the same concern as for electrical cars: will the charge last for the whole trip? If not, you'll have to pedal-drive a lot of additional mass accounting for the motor and battery.
Cost is the overarching reason. Not only buying (and re-buying after theft!) but also maintaining. I can happily leave a cheap bike in the rain for a year; at worst I'll buy a new chain (€10) that I can easily replace myself. I'm living now in a relatively flat city of 250K with over 50K of students: I can buy a second-(well, probably third- or fifth-)hand bike for €75 that'll serve me for a few years. Replacing or upgrading parts of the electric bike is comparatively expensive. The chance that a drunken vandal completely destroys it is small, but it does happen. There's safety in numbers: My €75 bike (with a €50 motorbike lock!) will not be targeted, while an expensive electric bike would. Another factor of the cost equation is market volume --- electric bicycles would get much cheaper if more were sold. But they aren't for previous and following reasons.
Unnecessary. There's little point in an electric bike over short distances and rather flat terrain.
Insurance and regulations. Technically, an electric bike would require motor vehicle insurance of about €150/year here, and hence also a yearly inspection (cost) which will require better standard of maintenance --- for example, replace tire when depth gauge officially too little, not "with the next puncture after it's visibly worn out" as usual. If you are involved in an accident (whether causing or not), judgement may go very different depending on it being a regular or electric bike. And police here apply same 'drunkenness' standards for pedestrians and cyclists (so, after a few cans you're fine; unless aggressive then it would be more under 'breach of the peace' regulations that you have problems), while cars, motors and electric bikes would fall under specific Mg/L alcohol concentration rules (where you are breaking the law long before a policeman would address you for being 'drunk in public').
Crash your electric cycle into a parked car and you probably lose your driving licence; same with your normal cycle and you can just reimburse its owner.
I live in The Netherlands, where cycling is one of the most (if not the most) popular modes of transport, with an average of 1.3 bicycles owned per person (22.7 million bikes / 17 million citizens) [source].
So far, 1.9 million electric bikes have been sold country-wide. That roughly means 1 e-bike per 10 non-electric bikes sold, and 1 e-bike per 9 people. I'd say that's fairly mainstream.
As mentioned in other answers, e-bikes cost quite a bit more than regular bikes, meaning they're less likely to become as common.
The expense is part of it: for the price of a cheap electric bike I can buy a much better bike without a motor.
A much bigger effect is that electric bikes are still bikes, with all the exposure to the weather, perceived risk, and at least some of the effort. So tempting people out of their cars onto electric bikes is a hard sell. Tax breaks might help but would have to be significant given the upfront cost. Electric bikes are generally too expensive for schemes like the UK bike to work scheme.
Getting people who ride normal bikes onto electric bikes means starting from a small number of people in the first place, and again you've got the upfront cost plus they're not much quicker than pedal bikes in many places due to legal restrictions.
What is the biggest issue to bring them to the mainstream market?
I live in Tel Aviv and here electric bikes are very frequent. The reason is probably a combination of climate, traffic congestions, coolness, and the size of the city.
The reason that some people still use manual bikes is mostly the cost, but also the possibility of theft, particularly of the battery. You actually see people that carry the heavy battery with them in recreational places, workplaces, religious buildings, etc.. because they fear it will be stolen otherwise. Still another reason can be the willingness to exercise a bit.
As an electric bike owner I'd say there's a relatively small niche where they're useful.
For eg my commute is currently 6 miles and hilly enough to break a sweat. I bought an e-bike so that I don't have to change clothes when I get to work - but would never use it for anything else! (And will probably have to get rid of it when I move house closer to work..). They're speed limited as well as range limited so in any of the following cases:
you're much better off with a normal, lighter bike. Mine is so heavy I can't lift it up stairs, which also restricts for eg, taking it on the train.
Additional points from a former ebike rider:
I've had an electric bike, and it got too dangerous for my taste.
It was an old rigid MTB with a front wheel motor, and despite weighing about 25 kilograms (55 US pounds) I could consistently achieve speeds of 40+ km/h (25 mph) and peaks of 45 km/h (28 mph) It was "rated" at 300W the legal maximum here.
An electric bike can let you get into more energetic collisions because of the velocity increase, and therefore the increased momentum.
Related - other road users can fail to observe your real forward speed. I've had multiple times where a car would pull out in front of me because they thought they had time to get out of the driveway or round a corner. This can be termed "looking but not seeing" where they observe a bike 50 metres away, check the other way, go, and I've ridden that distance before the car has completed the manoever. 50 metres is only 4 seconds at 45 km/h.
Some ebikes allow the rider to not pedal. This decreases the rider's overall visibility even more than just being on a bike - something about the vertical movement of the legs helps indicate to other road users that you're a bike. Sitting stationary can make an ebike look like a person standing still from some angles.
New transport options bring changes - and it takes three generations before those changes become natural. Electric cars will take 60 years to become completely normal and ubiquitous, cos thats about how long it took for horses to disappear completely from the road transport network.
I live 12 miles from work. I have been toying with an electric bike - I own a "normal" bike, which I've not really used to commute much - 12 miles is a long way when you're out of shape.
For me, the core problems are:
Otherwise I'm a firm fan - they'd have the same drawbacks of weather/traffic, but with a more reliable pace, and a good chance of arriving without being hot and sweaty.
But I still find it hard to justify a few thousand on a bike, when an annual bus pass is £800.
As of 2023, electric bikes (the type with electric support up to 25 km/h) have become mainstream in Central/Western Europe.
More than half of newly sold bikes in Germany are electric, with the trend increasing. Anecdotally, when I'm cycling in hilly areas in central Germany, the large majority of touring bikes or mountain bikes are electric. My estimate in Odenwald or Spessart is that more than 90% have electric assist. It makes going up a 10-15% slope a lot easier, in particular for older people, who otherwise wouldn't be riding there at all. Only road bikes remain mostly/overwhelmingly pedal powered, which makes sense, because riding a road bike is about sport and perhaps competition, whereas touring or commuting may be more about getting somewhere or enjoying a day out (and for this reason, there aren't many electric road bikes out there). Among freight bikes the market share of electric bikes is even higher; finding a freight bike to transport kids, dogs, or goods that does not have electric assist is difficult (and I can attest from personal experience that pulling 150 kg up an even gentle 5% slope is slow and tiresome; I haven't tried 10%).
There may still be places in the world where regulations are lagging behind, and they remain much more expensive than regular bikes — but they have clearly and definitively arrived in the mainstream.
I use my bike mainly for transport in and around the city (~100k residents, Netherlands) I live in. Although an electrical bike would be convenient when I have to commute for larger distances between cities/villages, it is pretty useless inside the city. This is mainly because of lack of e-bike infrastructure.
Now I am told that the Netherlands has all these convenient biking lanes, but in the city my biking speed is usually limited by the amount of corners, traffic lights and other people on the road. Not by speed I can reach on quiet roads in the countryside, with or without electrical motor.
So the real reason is cost / benefit. I'm willing to pay more for a fast bike, but only if it's really faster. I am not paying for an expensive bike if I can't really make use of it inside the city.
There are three simple reasons why the population choose a traditional bicycle over an electric. Note that I am not discussing why someone chooses an electric bicycle, as I think those are different motivations.
For me, it was not practical. 2014-2018, 99% of my transportation was bicycle. Battery range was insufficient to get to the next village in many places, so I’d have to push all that extra weight up every hill. And then I’d have to find a place to recharge.
Historical inheritance of the moped is a problem.
Some persons with limited experience see moped and E-bike as very similar means of transportation, and the reputation of moped is not everywhere good. It may be seen as unsafe both for the driver and for others and while depending on the infrastructure it can be very efficient, at places is anyway seen as mostly used just by teenagers for fun. I see the road signs prohibiting them at almost every forest road I pass.
Hence when buying an E-bike, you face certain fear, uncertainty and doubt, if not from yourself then from your family. It is obviously not the same as when buying an ultralight or even motorbike, but some is when cars and ordinary bicycles are not impacted by this feeling.
It seems important to differentiate the 25 km/h version of E-bike from the fast 45 km/h version and from motorbikes and mopeds of any kind.
Here in Northern Ontario, Canada, a certain type of electric bike is quite popular. It is mostly a bulky electric scooter with pedals attached.
They're popular since they can run on public roads, but do not require insurance or a motorcycle permit since they are still classified as bicycles.
Interesting that most answer focus on the vehicles rather than the infrastructure.
Lanes is one part of the problem, parking is another one. A lot of politicians think that building lanes will bring bikes (electric or not), but forget about the parkings.
E-bikes being expensive and more prone to theft, they need more secure parkings to be used and adopted. The majority of people living in cities (even in bike friendly countries) don't have convenient and secure parking at home or at work. You need both to commute with an e-bike.
An e-bike is certainly expensive compared to a regular bike, but are very cheap compared to a car, and in bike friendly countries, there are incentives to use bikes instead of other forms of transport. So the argument of the price alone doesn't explain that.
The main reason why electric bikes aren't mainstream is the fact that human legs and electric motors want to produce power at much different RPMs.
Casual cyclists pedal at around 60 RPM. Experienced cyclist can pedal at higher RPMs, 90 RPM. Both of these are nothing when compared to optimal electric motors that want to rotate at 10 000 RPM, if optimized to produce the largest possible power with lowest possible cost and lowest possible weight.
At 25 km/h, a wheel with 2m circumference rotates at 208 RPM.
So, pedals rotate more slowly than wheels (about 3x difference), whereas optimal electric motors want to rotate at about 50x faster than bicycle wheels.
Engineering has allowed us to create a motor producing 250 watts of power within the hub of a wheel. This is bit over what casual cyclist can produce continuously. However, even causal cyclists can climb up short hills at over 500 watts, more than what these hub motors produce.
These hub motors also are heavier than necessary due to being restricted to about 200 RPM, and also more expensive than necessary.
If you want to create a cheap lightweight electric transportation vehicle, you need to have the gearing to increase RPMs at the electric motor. This means a drivetrain that increases RPMs at the power source, rather than decreasing them. Thus, you need to get rid of the pedals because there is no way to have both the existing drivetrain for pedals and the new drivetrain for the electric motor. It won't be an electric bicycle anymore. Such a vehicle needs to be insured.
On some countries, vehicles that:
...can be used without insurance. They are barely adequate, but heavierweight and more expensive than necessary due to the limitation that the motor needs to be in a wheel hub, and thus rotate at suboptimal RPMs.
I believe that by eliminating the pedals, you could easily have 750 W of electric assist at up to 40 km/h, in a lighterweight package than most electric bikes, and also for a cheaper price tag than most electric bikes. However, by eliminating the pedals, it won't be an electric bike anymore.
A long time ago, there were motor vehicles with pedals, called mopeds. Then afterwards, it was realized that it is better to eliminate the pedals. The vehicles are still called mopeds even though there are no pedals. I believe a similar thing will happen with electric bikes. The pedals will be eliminated, and thus, we end up with electric scooters.
