BMW C Evolution

[Bluebottle]

Gimme gimme gimme....

BMW are ramping up promotion for the C Evolution in the UK. London video here

[michaelphillips]

Gimme gimme gimme....

BMW are ramping up promotion for the C Evolution in the UK. London video here

Well it looks superb, the front headlight styling has that same "ive got my own helmet on" style that the tmax 400 has. important info, needs to be range... price.... battery type.. i cant understand why car or motorbike manufacturers cant get there heads around that your wheels are spinning when moving, a car has an alternator to generate power, and an electric motor is the reverse, that is used to power electric cars and scoots.... so why cant they incorporate an alternator type system to continually put volts back into the battery pack...

or is it the same attitute of trickle feeding us new types, as they are in cahoots with the oil company scenario

[michaelphillips]

New 2013 BMW Motorrad C Evolution Electric Scooter (Slides) with fairing removed, the battery pod is wel low which is very stable. Love the idea of an electric motor driving it...

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[Bluebottle]

why cant they incorporate an alternator type system to continually put volts back into the battery pack...

If I understand what you are asking:
Because if you take energy from the motion and turn it into elec, you've got less energy left in the motion and you have invented the electro magnetic brake.
But you're too late its been done It is a very old idea and was used on trams and trains in ye olden tymes.

Short answer = because you'd stop

Long answer - This is already done and it is particularly suited to electric PTWs. The motor inside the wheel has "regenerative braking" - whenever you use engine breaking the motor inside the wheel gets turned by the forward motion and becomes a generator.

The fundemental problem is that you can't create energy from nowhere, so:
You want the motor to drive you forward so you can't steal energy off it obviously
When you are freewheeling you have kinetic energy (speed) but you don't want to nick that because you would slow down.
Normal braking turns your kinetic energy into heat and mechanical damage/wear so that is just a waste
Engine breaking is the thing to go for, you have excess energy (speed) you want to get rid of so stick it in the battery.



A bike mechanic once told me that I was wasting my time building a regenerative braking system because they tried it on formula 1 and it doesn't work, I tried to explain but gave up, i would never convince him.
It goes like this :
regen. braking is ideal for a PTW. Unlike an F1 everything is already in place and you arent doing complicated mixing of power types sophisticated brake tech. on multiple wheels, balance problems etc.
The motor is sitting in the wheel already and wired up direct to the battery. Everything you need is already there and working apart from a simple control circuit. As an added bonus you get a free reverse gear too


Sorry if that sounds patronising or over simple, I might have misunderstood what was being asked.
Elecktrickery definately isn't my strong but I'm a convicted tinkerer

[gn2]

so why cant they incorporate an alternator type system to continually put volts back into the battery pack...

Because it would act as a brake.
You can't get something for nothing.

[bikerdezzie]

if ya want to ride round the city in style I would rather have one of these in electric, there stunning and probably a lot less than the beemer.
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[Mr Angry]

^+1

[Bluebottle]

Very nice but be careful

I think 250 watt makes it a moped in UK law and subject to type approval, insurance, construction and use regs, VED etc.

The law is expected to change to match Europe but I don't think it has yet (could be wrong, don't do this stuff anymore and haven't looked it up)

You would be in deep shit if there was a serious accident. Even if you weren't the vehicle could be seized at any time, usually you get charged with driving without insurance and smaller charges get hung on to that.

Customs might send you a bill too.

[abitmad]

It's rubbish compared with petrol power. It looks good and is probably nice to ride but where it counts, ie. practicality, it's rubbish.

Range is "up to" 100km according to BMW. That's about 62m. But if they claim "up to", the true range will be at least say 1/3 less, making a reliable range of about 40m if you're lucky. And this will deteriorate over time as the batteries wear and their capacity reduces.

Secondly, the recharge time is 2-3 hours. That's useless. Most riders want to use their bike when they want to use it, not be dictated by lengthy recharge times and lack of recharge places.

Quite apart from the probably very high cost like most things BM, there is hardly anyone who could find this practical compared with petrol power. But it's not just BM, recharge times, recharge places and range are the major problems of pure electric vehicles. Most criticism of electrics centres on their very limited range but in my opinion, unacceptably slow recharge times, even assuming you can find somewhere to recharge which frequently you won't, are at least as big a problem.

In theory I like the idea of pure electric vehicles, bikes and cars. But until they can compete on range and recharge times, with recharge points commonly available, they are not practical for most people. Though electrics may be forced on us anyway at some stage if petrol becomes scarce.

Hybrids like the Vauxhall Ampera which use a petrol engine just to recharge seem to be a great compromise because they get rid of the range/recharge time problem, but that idea is probably too complex, costly and heavy for a motorcycle.

[Bluebottle]

Range and charge time are definitely serious points.

However, the figures don't work the same way as when reading petrol figures.
Not trying to say your wrong, just that it needs reading with an electric-head rather than a petrol-head -things work differently.

Charge time is for a full charge. I have never done a full charge on any electric, usually just a 30 min top-up, occasionally 2 hours. Same as you wouldn't try to fill your tank again after using a litre

Also the charge isn't linear. It ramps up quickly at the start and then gets slower so the bulk of the charge goes in early on. A quick boost will get you most of your range back

Range - I can get exactly the range the manufacturer quoted, but power starts to fade in about the last fifth of that (you don't suddenly stop). Some manufacturers quote "useable range" with performance at a reasonable level; some quote "total range" where you slowly grind to a halt.

I budget to use 2/3 of the max range and then don't worry about detours or battery deterioration, won't suit everybody but it works for me.