Electric bikes, the next step

[Whysub]

Every producer of batteries (and chargers for that matter) think theirs is better than everyone elses, so i can't see any common battery, just like we don't see all car makers using the same ICE.

Oddly, i think many manufacturers use the same electric motor, seeing as there are only two moving parts in each one, they are pretty much the same.

[cheb]

Looking at the Zero site, their bikes use belt drive. Am I right in thinking electric motors will be less harsh on chains that an ICE? Could a direct drive motor be fitted in the rear wheel without affecting the handling badly? A lot of extra unsprung weight is my assumption as to why they aren't already used.

[Yorick]

Will a shafty leccy motor wheelie ?

[cheb]

A hub motor would make 2WD bikes simpler too. If that's a good thing.

[The Spin Doctor]

I would guess the common battery is more about reducing battery cost through greater volumes than anything else. Maybe not though.

Absolutely - which is why you'll see it in high volume, low cost, low margin machines.

[A_morti]

Looking at the Zero site, their bikes use belt drive. Am I right in thinking electric motors will be less harsh on chains that an ICE? Could a direct drive motor be fitted in the rear wheel without affecting the handling badly? A lot of extra unsprung weight is my assumption as to why they aren't already used.

The fastest electric scooter with a hub motor which I can think of is the Niu n-gt. It has a top speed of 70km/h. The hub motor just barely fits inside a 12" wheel. Above that speed, everything has a mid mounted motor and a belt or chain, so I assume the hub motors can't yet generate enough power for use in a "proper" bike. Or maybe the penalties in unsprung weight (handling) are too great.

There's definitely advantages to hub motors. They are silent, properly silent. They have no transmission loss. No belt or chain to replace.

Still, it's all just a matter of time. If you shown a certain Mr Sinclair the hub motor and lithium battery in a modern electric scooter just 35 years ago, he wouldn't believed his eyes.

[A_morti]

A hub motor would make 2WD bikes simpler too. If that's a good thing.

Would already be an interesting thing to see development of via racing, particularly on Motocross bikes.

[Mr. Dazzle]

Every producer of batteries (and chargers for that matter) think theirs is better than everyone elses, so i can't see any common battery, just like we don't see all car makers using the same ICE.

There's already a huge amount of sharing in ICE vehicles. OEMs build very little of anything themselves, their primary job is to coordinate lots of sub suppliers...all of whom sell to multiple OEMs. There's alot of crossover.

It even goes as far as engine and platform sharing. On top of the obvious VW/Audi type stuff, BMW and Jaguar share EV tech, Aston and Mercedes share engines, Toyota and BMW share platforms and engines...etc.

Oddly, i think many manufacturers use the same electric motor, seeing as there are only two moving parts in each one, they are pretty much the same.

EV motors are simultaneously very simple and very complex! They only have a couple of moving parts which means the devil is in the detail. Inevitably that means at the upper end - the sort of thing you'll find in a road vehicld - there is a lot of subtle yet important difference from model to model.

[Le_Fromage_Grande]

A hub motor would make 2WD bikes simpler too. If that's a good thing.

Would already be an interesting thing to see development of via racing, particularly on Motocross bikes.

It'd handle like a pogo stick, all that inspiring weight flapping about, but leccy is definitely the only future off road motorcycling has.

[Mr. Dazzle]

The problem with hub motors is power density, cooling and cost.

Road vehcile motors are pushing the limits of material and manufacturing technology. Getting something that gives the required torque and speed in a small package, but which doesn't overheat or cost a million quid, is quite tricky.

Speed limits are harder than you expect, EV motors are generally spinning at 10,000rpm plus...up to 20,000rpm in top end supercar type stuff. Getting them to not fly apart is a challenge! Even in a hub motor you'd have a planetary gearbox for a step down ratio, spinning the motor faster is generally more efficient.

You could fit hub motors no problem, but you'd be back to crappy whiny milk float motors, not the smooth ScFi sounding mega power stuff everyone associates with EVs now.

[Horse]

A hub motor would make 2WD bikes simpler too. If that's a good thing.

Would already be an interesting thing to see development of via racing, particularly on Motocross bikes.

It'd handle like a pogo stick, all that inspiring weight flapping about, but leccy is definitely the only future off road motorcycling has.

I think someone tried it ages ago, a hybrid ic rear wheel drive, small electric hub front, so majority of drive still to the rear.

[Tarmacsurfer]

You can spin a bike EV motor to 20k no problem, so final drive gearing is useful to move the usable torque range.
Belt drives are preferred due to lower NVH, basically when you have a quiet motor then you notice other noises more like chain slap.

The big oems will be matching fully fuelled IC bike kerb weights with the new EV releases in next few years. This and the improving cell technology improving range will be the big factors in moving people to switch.

[Whysub]

You can spin a bike EV motor to 20k no problem, so final drive gearing is useful to move the usable torque range.
Belt drives are preferred due to lower NVH, basically when you have a quiet motor then you notice other noises more like chain slap.

The big oems will be matching fully fuelled IC bike kerb weights with the new EV releases in next few years. This and the improving cell technology improving range will be the big factors in moving people to switch.

All very true, but maybe the biggest factor in moving people to switch is Government legislation, which is already influencing the vehicles people buy.

[The Spin Doctor]

Every producer of batteries (and chargers for that matter) think theirs is better than everyone elses, so i can't see any common battery, just like we don't see all car makers using the same ICE.

Oddly, i think many manufacturers use the same electric motor, seeing as there are only two moving parts in each one, they are pretty much the same.

The Big Four disagree:

https://www.webbikeworld.com/the-japane ... ric-bikes/

There are already a couple of other tie-ups.

Kymco have been working on swappable batteries for a while - it would make sense to standardise around the battery ,rather than end up with the current mix of standards for rechargeable electric cars.

https://electrek.co/2018/10/15/ionex-ba ... -22motors/

[dayglo jim]

It would be easy for the Chinese manufacturers to do this from the ground up, if you look at the range of mopeds you can see that, apart from badges and colour schemes, they are fairly homogeneous. OEM is not the same for them as so many contractors are involved in the process.

[Horse]

'Vintage Voltage' on Quest, just completed a conversion of an RE. Not a true vintage in that it was a disk brake version, but interesting to see the challenges of fitting it all into the available space.

[weeksy]

https://www.motorcyclenews.com/bike-rev ... /cr6/2020/

Here's the next step then. Standard household 3 pin plug charging, 4 hours to full.

Decent weight and enough power to shoot to the shops..

[Mr. Dazzle]

You do have to consider horsepower ratings on electric vehciles slightly differently. Unlike a piston engine an EV can produce peak power across most of the rev range...it essentially operates in 2 regions "torque limited" when the motor can put out peak torque, or "power limited" (at higher speeds) when it can output peak power. EVs essentially always have either full power or full torque available, depending how fast you're going.

Piston engines on the other hand only produce peak power at a narrow speed range.

In simple terms EVs are always in the power band.

It means an 8bhp electric vehicle has a lot more "go" than an 8bhp conventional vehcile. Imagine having an engine that was on cam at full power all the time...electric motors are a lot like that.

[Mussels]

I remember when e bike regulations specified a maximum power limit, it was almost impossible to measure the power output in a conventional manner so manufacturers could put on much more powerful motors than the rules intended without fear of prosecution.

[Mr. Dazzle]

Its further complicated by the fact you can overrate electric motors by a huge factor...you can double the power for a bit. The practical limiting factors are essentially just catching fire/melting (or cooking the electronics, same thing really) or physically tearing itself apart.

It's standard practice for EVs to have overrate and derate modes based on temperature etc.