Electric Bikes

[ChrisG]

Interesting. Honda, Yamaha, KTM and Piaggio join forces on battery bikes | News (bennetts.co.uk)

 

Honda, Yamaha, KTM and Piaggio are looking to come up with a standardised swappable battery design for bikes.  The idea that you could go to an equivalent of a petrol station and swap your flat battery for a full one seems to have been dropped by the car manufacturers (Tesla demo'd an automated system for a drive in drive out battery replacement, but it seems to have died a death), but could still be workable for the smaller batteries electric bikes will require, and would remove some of the range anxiety.

 

I still don't see a big market yet for electric bikes other than commuters and maybe offroaders though.

 

Loads of electric mopeds around here from rental companies, not had a go on one yet though.

[Studley Ramrod]

Interesting. That could be a game changer.

 

We had a friendly hipster dude on an electric bike (Zero)  join us briefly when we were in Spain or France.  It was super nippy and I was struggling to keep up on the 9'er when he accelerated.  He peeled off after 20 mins, presumably to charge up, which is the problem with them.  Once they can do a decent range, and/or one could swap out the battery in 5 mins, I'm sure many folks would be up for getting one.  I think we're years from there though.

[marko67]

Kawasaki are teasing a hybrid.

 

That has me intrigued.

[fixitsan]

I could see dealer networks having bike recharging available, but what if a large rideout comes through ? 10 electric bikes but only 6 batteries on the shelf ready charged ?

 

I could see petrol companies going for it as an easy way to boost their credentials, but only if the unit didn't need much attention by their staff. With my job I have a 'Bybox' storage box at a local petrol station, you sometimes see lines of these lockers at many petrol stations.....maybe one day we could see racks of bike batteries in a custom charging unit ?

 

The big car battery swapping system was done by a now failed Israeli company run by Shai Agassi, called 'Project Better Place'. I believe there is still a taxi company in Tokyo which has it's own drive in battery changing unit which still works.

 

The problem with the electric market at the moment is that it's incredibly volatile due to battery developments which are known about, and others which are rumoured to be coming.

 

Tesla are building a 'Gigafactory' to make batteries, more than one factory I think actually, where they intend to take raw lithium-bearing ore at one end and output finished battery cells. But he has had to go balls deep into lithium technology, while Samsung (or maybe it was Sanyo) are looking hopefully towards 'solid state' batteries. But then they are known to be ridiculously expensive at the moment, and all anybody has seen is some patent applications.

 

I think whoever throws money at it will end up with technology which is rapidly going out of date, but as long as governments create lows mandating electric vehicles then there is enough motivation to do it.

[ChrisG]

The problem with the electric market at the moment is that it's incredibly volatile due to battery developments which are known about, and others which are rumoured to be coming.

 

That could be a big selling point for swapable batteries, as the technology improves you package different technology in the same casing, and your range increases as the bike gets older.  They standardised on AA/A/C/D/PP9 etc cells years ago, and they technology has improved through zinc-carbon, zinc chloride, alkaline, nickel-cadmium, lithium-ion, etc, etc. 

[fixitsan]

That could be a big selling point for swapable batteries, as the technology improves you package different technology in the same casing, and your range increases as the bike gets older.  They standardised on AA/A/C/D/PP9 etc cells years ago, and they technology has improved through zinc-carbon, zinc chloride, alkaline, nickel-cadmium, lithium-ion, etc, etc. 

 

That's a good point

[chrisr]

I read that bikes arent included in the harebrained scheme - for the time being......

This post was last modified: 01-03-2021, 11:42 PM by chrisr.

[fixitsan]

Kawasaki are teasing a hybrid.

 

That has me intrigued.

 

After building my own electric I've toyed with the idea of building a hybrid.

A bike with an engine which is not powerful enough to provide great performance on it's own, running a generator. But the fact that it can keep the generator running at full output means it assists the battery power when needed, and charges it on the overrun. That would make it a 'series hybrid'

 

 

The downside is, if you don't make it a removable 'range extending' unit, then you're effectively carrying two engines, a generator and a main traction motor all the time, when only the traction motor is providing the drive at times, so a lot of weight and space for no return.

 

A part time petrol assist, or the other way around, where the electric motor provides the assist,(means you only carry a traction assist motor and an engine), makes it a 'parallel hybrid'

 

Honda got there first I think with the mk1 Honda Insight (alluminium honeycomb body, nearly impossible to repair). They turned the engine's  flywheel into the magnetic rotor component both for the generator and for the assist motor..

 

Something like this last system might work on a bike, because you already have an engine and a flywheel/rotor permanently connected. There's a couple of videos on Youtube of people playing about with something like that. Obviously though, because the flywheel is always connected to the crank it means that when you are motoring on electric you also have to turn the engine over, hence why it could only be used for assist/boost. Decoupling the flywheel from the crank would give the best of both worlds but that means a complete redesign of the drive to the gearbox. Alternatively, fitting one of your wheels with a central hub motor could do well enough to carry you around town in silence. In Edinburgh all the city centre roads are 20mph limited now, so that would be ideal, in terms of efficiency and noise

 

but in theory, a 125cc engine, with an oversized rotor charging a traction battery, with a 'bidirectional'  charge/drive controller, might be able to give another 3HP boost. 3HP of electric power is much more useful than 3HP of internal combustion at lower speeds, due to the instant torque of an electric motor. Scaling it up to larger engines is probably going to work too, up to a point.

 

The usefulness of that is that you could recharge the batteries at home too before setting off, so if your commute is a short distance you might never need to pay for petrol except on longer runs. 2p per mile for electric, versus 7p per mile on petrol. But  I mean, if you were so hard up in the first place you probably wouldn't be able to afford to buy that sort of bike in the first place ! Conscientious greenies might be keen though

 

I think the manufacturers know that they could create a selling point for their new bikes by making them hybrid, but then what will that mean in terms of legislation - will it make legislators think that they should bring forward the introduction of an 'electric only' policy ?

 

 

Edit. I just noticed this on fleabay. It's the rear wheel of an electric motorcycle, claimed speed of 65mph. That would make a useful front wheel conversion. Maybe not on the TDM because it's already a bit heavy, but my KTM is needing some work, it's already light and has space for some batteries.   Tempting, apart from the fact that it adds a lot of usnprung weight going from an alloy rim, to a rim full of heavy magnets and iron. It might get a bit thumpy on potholes ! https://www.ebay.co.uk/itm/Bosch-17-3-in...SwXIpgOCxf

 

It could be exciting having it boost the power, but the KTM already lifts the front wheel easily under power so I'ld just be spinning it in the air for nothing ! And it might be a big fight to get it turned into corners too....

This post was last modified: 02-03-2021, 09:12 AM by fixitsan.

[steve27bha]

.....

It could be exciting having it boost the power, but the KTM already lifts the front wheel easily under power so I'ld just be spinning it in the air for nothing ! And it might be a big fight to get it turned into corners too....

 

If the generator wheel is as heavy as you suggest perhaps the wheelies would be kinda difficult? Or is the KTM enough of a hooligan to cope? - or are you!


 

[fixitsan]

 

If the generator wheel is as heavy as you suggest perhaps the wheelies would be kinda difficult? Or is the KTM enough of a hooligan to cope? - or are you!

 

I did think that, but I don't know if I want to try it !

I'm sure the steering would be too slow, but practical all the same probably, if you took it easy.

 

The other thing which would bother me, would be if the generator/controller failed and shorted a couple of windings together, because that would feel like jamming the front brake on, mid corner.... I'm not brave enough for that

[TKH]

A Chinese company has I think it's nearly 200 and counting stations to remove and replace batteries for their brand of cars. 

I wouldn't mind an electric bike but the range on them so far whether or not you can swap out a battery is just too short. A ride over North Yorkshire for me would mean either taking it fairly easy or running  out of juice. I guess if the battery units are small enough in future you could carry a spare? or a "limp home" battery.

 

I terms of making a hybrid you could have a switch to call on power when you need it? Replace the front brake calliper with a small generator which could be spun up somehow by pressing against the disk. That would give you the choice of re-filling the battery by braking with the front or just using rear brake, or both. The hybrid battery could be carried in a rear box/top box. Just a thought.

[ChrisG]

I wouldn't mind an electric bike but the range on them so far whether or not you can swap out a battery is just too short. A ride over North Yorkshire for me would mean either taking it fairly easy or running  out of juice. I guess if the battery units are small enough in future you could carry a spare? or a "limp home" battery.

 

That's another reason why I think they initially make sense for the commuter market, the majority of rides are going to be a known distance.

[fixitsan]

 

I terms of making a hybrid you could have a switch to call on power when you need it? Replace the front brake calliper with a small generator which could be spun up somehow by pressing against the disk. That would give you the choice of re-filling the battery by braking with the front or just using rear brake, or both. The hybrid battery could be carried in a rear box/top box. Just a thought.

Not a bad idea at all

 

In terms of power it takes about 3HP to push a well designed (aerodynamically) bike along at 50-60mph on the flat (It's about 10HP for small car).  A 3HP motor is quite beefy. Smaller motors would definitely work but then only as a low speed assist/town mode, but it might be worth considering if ULEZ becomes any more restrictive, when a retrofit kit might be offered ?

This post was last modified: 02-03-2021, 05:35 PM by fixitsan.