Electric bikes? performance/range/battery life where are we?

[STONEY!]

I know nothing about e-bikes, where are we in terms of technology and price for that matter?

I see a lot of places claiming 50+ mile ranges some even stating over 100 miles is this realistic?

Same goes for performance ive seen adverts for anywhere from 20-60mph?

One claimed to do 35mph and have a 120 mile range with no need to peddle! Is this really possible?

any reccomendations of what to buy or am I better off building something?

[Baffler186]

I had a Wisper e-bike, IIRC the battery was 37v 17ah. It would maintain 15mph on the flat, but I never used it "electric only" i.e. I always pedalled as well. The claimed ranges would be realistic in very flat countries. I did 70 miles on a full charge and it had a quarter battery by the end of it, but that was with me pedalling. I would think not more than 20 miles with the "throttle" only on flat roads. And forget going up any sort of hill without pedalling.

The maximum range is not something you should go near on a daily basis though. When they start wearing down (i.e. less than a quarter charge left) they become hard work. it's not like an MP3 player where it will play perfectly and then shut off at 1% charge. At 10% charge I would be dragging that motor around, that coupled with a 25kg bike does not make for a leisurely time!

As for speed, most of the lower budget e-bikes (£500 - £1500) will be limited to 15mph as per Eu regulations. I've seen some that claim 25-40 mph but they are obviously more expensive and not strictly road legal.

There are a couple of good build threads on here, and those guys certainly know what they are doing, and yes you'd get a hell of a lot more performance for the price, depends if you know your stuff though.
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Current: 2009 SV650 S, 1990 Kawasaki GT550
Previous: 2009 CBF125, 1998 GSF600, 2004 FZ6 Fazer, 1978 CB400a Hondamatic

[monkeybiker]

Have you tried one of them bikes with a petrol engine fitted. I hears they is better

[kramdra]

Lipo RC batterys are cheap, but controllers are still a bit shit and Ive not yet chosen one for my bike.

35mph at 120 miles is bollocks. That would be quite a heavy and expensive battery pack. About 600 quid worth of cheap RC lipo and 16 KG of weight (Im estimating 2400w/hours, which would be something like 50v x 50Ah... which is 20x 6s 5Ah lipos).

I will be using 500w/hour worth of batterys (4x turnigy 6S, 5Ah lipo, £130). Im expecting that if I pedal (as normal, 100% effort) I should be able to commute 40 miles and bring my average speed from 14 upto 25mph+. I could buy another 4 and double the powar or range but bike will be running out of space to put them

[G]

What is your intended purpose of the bike; what would you like it to do?

Range can easily be added with more money spent and more weight.

[STONEY!]

I have no intended purpose for the bike it was more out of interest, there are things I would like:

An electric bike for greenlanes/byways/cycle paths etc would be cool something you could go anywhere on without getting bothered and ideally not have to pay tax/insurance etc on

Something for short journeys ie under 10 miles each way commuting on the road.

[G]

[The Artist]

Currents spec of my commuter bike that I use daily.

45v (2x 22.2v 6S 5Ah LiPo in series and then 2 of those in parallel)
This gives me 10Ah @ 45v. I actually have another identical battery set but I just don't need them for my commute.
I do ~9 miles a day and honestly don't really pedal at all. I have a 2kW controller but I am actually only drawing 1800W from the batteries at maximum throttle so I reckon maybe 1400W at the wheel.
Total bike + rider weight = ~140KG's. Not weighed but I am a fat bastard and the bike was a very heavy bike to start with. Battery pack is about 3Kg's and the motor is 6-8kg's.
I top out at about 30kph but that is 100% the controller. My old controller I could get nearer 45kph with a bit of a runup. I actually prefer this limit, it means I am less likely to draw attention to myself and crash and die.

So with a full 6kg battery pack on my 140kg bike, I could do around 23-25 miles without pedalling and I am sure a lot more if I put some effort in or didn't go full throttle everywhere which I do.
If I reduced my power limit to 250W then in theory I could get over 100 miles but 250W is for pussies.