electric bike kits

Electrically assisted bikes, trikes, etc.
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willcee
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electric bike kits

Postby willcee » 15 Aug 2013, 10:48pm

Having had a couple of outings on firstly a Cube, a dedicated E bike, and lastly a Merida hybrid equipped with a cyclogic front hub kit.. i was duly impressed and enjoyed both short rides, same test route , a blooming steep hill which would have been a tight ride on any of my lightweights.. since then i have been considering seriously building one from scratch on a lightweight hybrid , or touring frame.. I have been searching on the web and am more confused than ever, i do know that i would want more speed than the UK allows and will require pedal sensing. as well as a thumb throttle, and would wish to use drop bars.. Anyone on here that could help me and advise what i should look for or who has already built a machine?? i would be very grateful.. i would have no problem with the mechanical aspects of any build, electronics however would be a different game entirely.. Will

Brucey
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Re: electric bike kits

Postby Brucey » 16 Aug 2013, 7:19am

local to me there is a vendor of kits for conversion. There are many, many options and there is new stuff coming out all the time, getting better/cheaper etc. For people who can't manage to break sweat even a little ( remember that effort comparable to walking gives 12mph average speed on a bike...) I guess they make a some sense
.
However, whichever way you cut it, you end up with a bike which weighs about double and is as demanding as (say) a mobile phone in terms of wanting to be charged up etc. By definition it immediately becomes a somewhat poor bicycle; you can't have your cake and eat it too, you know.

As for higher speed assistance I am sure that this would be a be a bit of fun in the same way as riding a motorbike is. However the reasons the assistance speed is limited are manifold, and are not unrelated to the fact that if you nail this kit onto a bicycle, you have immediately used up most of any spare weight capacity, and if you increase the speed as well, you suddenly have a vehicle with wholly inadequate tyres, wheels, brakes etc for higher average speeds.

To re-engineer that to be adequate, you would end up with a bicycle for the road that would be related to a road bike in the same way as (say) a DH bike is related to an XC bike, but stronger again because of the added (probably unsuspended) weight of motors and batteries. An even worse bicycle, and one that probably needs taxing, MOTing, insuring, etc etc . :roll:

So for me, the bottom line is this; if you don't want to pedal, get a motorbike, or an electric scooter. If I genuinely couldn't manage a decent average speed any more through injury or ill health, I might think about an electric motor to help me along when I nip to the shops or whatever, but frankly that day is a long way off yet; fitting one ahead of time might well help to bring the evil day when I wouldn't have any choice closer.

cheers
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Chris the Sheep
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Re: electric bike kits

Postby Chris the Sheep » 16 Aug 2013, 8:41am

I can't offer any advice on kits as my bike was a factory model - and it's a big tough 'Dutch-style' bike that I wouldn't want to ride without assistance. One reason I bought a ready-made bike was the confusion around kits - there's lots of info on pedelecs.co.uk but it's a strange site, with vendors / importers popping up on every thread giving advice with good intentions but inevitably not impartial.

From what I can work out, the term 'pedal sensing' can mean two things; either a simple switch that turns on the power to whatever setting it's on, or a torque sensor that provides power in proportion to your effort. I suspect most kits are the former, especially if they have a 'throttle', and that the riding experience is completely different.

Regarding drop bars - that shouldn't be a problem with the 'torque-sensor' type, but for the simpler on-off you have to guard against power being applied at the same time as you're braking. That would need cut-out switches in the brakes, and I don't know whether they're available for drops (I think there's some sort of inline system available).

In response to Brucey, yes an ebike is a compromise and without power it doesn't make a particularly good bicycle (but it will get you home); but a good torque-sensing bike provides an enhanced cycling experience that's nothing like a motorbike. With a 15-16mph cut-off it's not as quick as a conventional bike over distance (you can pedal faster but it's unpleasant) but the acceleration in traffic is a joy. And as I've said in other threads, they bring benefits for utility cyclists in general, not just the unhealthy.

I do still ride my conventional bike regularly, and on a calm day or with a tailwind it's great; but in a headwind at the end of the working week, give me the ebike any time.

That's legal ebikes though - personally I don't like the ease with which people can ride unrestricted ebikes on the road and get away with it - the power and speed rules are about right to allow safe use on the same roads and cycle paths as a normal bike. Too much abuse means we could end up with all ebikes being banned from cycle paths, or some other draconian rule.

Brucey
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Re: electric bike kits

Postby Brucey » 16 Aug 2013, 9:02am

Chris the Sheep wrote: ...With a 15-16mph cut-off it's not as quick as a conventional bike over distance (you can pedal faster but it's unpleasant).


Except for headwinds and hills (which ought to average out in the long term...) I'd always expect to go faster on an ordinary bike without great effort. After all 'walking pace effort' = '~12mph average' on any reasonable bicycle. And by 'reasonable bicycle' I would mean one that isn't at least twice as heavy as it should be, because it is laden down with a load of batteries and motors etc. On such a reasonable bicycle you can even ride faster than 15-16mph and it isn't especially unpleasant....

That's legal ebikes though - personally I don't like the ease with which people can ride unrestricted ebikes on the road and get away with it - the power and speed rules are about right to allow safe use on the same roads and cycle paths as a normal bike. Too much abuse means we could end up with all ebikes being banned from cycle paths, or some other draconian rule.


I agree, it doesn't make sense to allow higher assisted speeds in 'mixed traffic' of pedestrians and cyclists, especially not on our cyclepaths. In Holland I gather that you can even drive some kinds of 'micro-car' on their cycle paths; they are a completely different thing.

BTW if you wanted to go about 15-20mph average for modest effort on a ~25kg machine, I'd suggest a velomobile or other streamlined machine. However, they make much more sense in places where you can use them on cyclepaths more easily.

cheers
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pstallwood
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Re: electric bike kits

Postby pstallwood » 16 Aug 2013, 9:36am

Have a look on this forum

http://www.pedelecs.co.uk/

Peter

Al Wright
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Re: electric bike kits

Postby Al Wright » 16 Aug 2013, 10:16pm

Here is a link to BikeRadar review;
http://www.bikeradar.com/gear/article/b ... its-30175/

Check Sunstar So3 website, they produce a BB mounted motor kit.
Also Greuber Assist; http://www.vivax-assist.com/en/produkte ... ssist.html
a nice unit but expensive and specialist fit.

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willcee
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Re: electric bike kits

Postby willcee » 16 Aug 2013, 11:20pm

thanks guys, i surely started a touchy subject for diehard pedallers, while i won't ever be considered a Luddite, i am open to modern technology and in its proper place i think electric kits have their niche, before i would diss them i would have a go and did and was extremely impressed by my trials.. this will never take over from my good lightweight bikes , its an exercise that will have me hopefully building one from a frameset with lighter components as will suit the finished machine, as to tyres and brakes and their ability to control the power i won't be putting more than 300 watts through the frame and thats not as much as a decent pro these days, brakes similar situation, as i live in the beautiful Ulster countryside i won't be dicing with town traffic and my main intention is to use it on winter outings with full guards, and to do various short journeys where i would normally travel on 4 wheels...will

Brucey
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Re: electric bike kits

Postby Brucey » 16 Aug 2013, 11:47pm

300W is enough to go at a reasonable lick, but even with modern batteries you won't be able to keep that up for all that long.

You might think that the brakes wheels and tyres need be no more strong than those of a pro's bike if you are doing 300W. Not so. Most of us weigh more than a pro cyclist, and a pro cyclist doesn't rigidly strap 20-30lbs of crap onto his bike, either. Remember that to all intents and purposes the bike can be regarded as unsprung weight.

If you whizz about on this device in the wintertime I expect you to get incredibly cold if you don't pedal as hard as normal, and of course the faster you go the more the wind chill is, too. If the law spots you whizzing about at any speed they could pull you too.

I'm all for experiments, but I am waiting to be convinced by this one; do let us know how you get on!

cheers
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willcee
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Re: electric bike kits

Postby willcee » 17 Aug 2013, 12:20am

Bruce, yes i know, i understand your protestations.... as someone who used to build and drive rally and hillclimb cars, i'm certain that i can and will build a decent strong and light electric kit on a decent frame, which will be suitable to my purpose, perhaps this wont ever please the die hards, but i'm looking to suit myself , always do, always will. Pedal assist is like having a 30mph tailwind.. try it sometime.. i look forward to your usual detailed report on your findings.. as to police , they come to me and have their bikes sorted, most of them wouldn't know a cottered crank from a drum braked hub.. and i only want 20 ish mph, i can do that most days, that tailwind effect is addictive..will

Brucey
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Re: electric bike kits

Postby Brucey » 17 Aug 2013, 9:16am

if I were to say that I had never built a bike/motorcycle/car/ gizmo that wasn't 100% sensical, on little more than a whim or fancy, I'd be lying... :wink: :roll: :shock:

Sometimes though, I do wish I had thought a bit harder about it before I started; in retrospect a little more constructive criticism (which is not easy to tell apart from other forms of criticism at times....) might have come in handy.

So whilst I can see all kinds of possible pitfalls etc I am genuinely interested to see how you get on!

cheers
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squeaker
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Re: electric bike kits

Postby squeaker » 17 Aug 2013, 9:43am

Take a look at AtoB magazine. The proprietor, David Henshaw, runs a retrofitted e-assisted Brompton, amongst other things, which is a great bit of kit, especially when combined with trains for long distance. IIRC, one of his more pertinent comments is the consistency of journey times, as the assist helps tackle headwinds (and hills, on 'new' routes).
"42"

ians
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Re: electric bike kits

Postby ians » 17 Aug 2013, 10:51am

Hi

I've converted my Thorn Raven Tour - I can no longer manage to ride my bike without some sort of help. It's a simple bit of kit; motor, battery, controller and wiring harness. I had it fitted by the retailer, but I reckon I could put the kit together myself now. It's a Sparticle (which I understand they use on Bromptons).

I went for a kit because I like my bike and I thought that if it did not work out I could sell the kit and still keep the bike. As it is, it's worked very well for me. I just use it when I'm really stuck, like a long hill or a headwind. I have a twist grip (came with lever, but I changed it). I call it 'the invisible hand'. When I was a lad on my first club ride I was struggling on a big hill on the way home and one of the older member just put his hand in the small of my back and gave me a push till I got to the top. Now ill health has put me in the same position.

The motor is in the front wheel and the battery is in the bag on the rack. Hope this helps. Send me a message if you want more details.

ians
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Urticaria
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Re: electric bike kits

Postby Urticaria » 17 Aug 2013, 10:57am

Our man in the fens has been affected by the easterly wind I'm afraid. Neither winds nor hills cancel out in the long term using the obvious metric of journey time.
The idea of an electrically assisted bike for load averaging makes a lot of sense for a commuter or utility cyclist. It need not be 'twice as heavy', especially using one of these with something like a super capacitor, or perhaps more practically a LiPo battery.
I don't think you need fear the increased windchill either if you are in the habit of wearing clothes. Presumably, if you were to find an icicle forming on the end of your nose, you could always turn off the electrical assist, and then you would become hotter than on a normal bike because you are lugging around a doubly heavy object at a lower than usual speed. Perhaps you could factor in the cost of a nose warmer when you purchase your electric conversion kit?

Brucey
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Re: electric bike kits

Postby Brucey » 17 Aug 2013, 11:30am

Urticaria wrote:Our man in the fens has been affected by the easterly wind I'm afraid. Neither winds nor hills cancel out in the long term using the obvious metric of journey time.


not quite, no. And if the hills are mountains and/or the winds are hurricanes, not nearly. But it is of course more true for those who might ride at speeds of up to 15mph than it is for those who ride at higher speeds than this.

The idea of an electrically assisted bike for load averaging makes a lot of sense for a commuter or utility cyclist. It need not be 'twice as heavy', especially using one of these with something like a super capacitor, or perhaps more practically a LiPo battery.


I don't disagree in all cases, and the kit you have pointed out is neat and pretty lightweight; as I said things are moving apace in this market. But that is a 200W system which will help you (rather than power you without effort) for only a short period of time; presumably if there is no pedalling, the battery will be flat in a much shorter time than quoted (perhaps even less time than the OBB bearings you are forced to use will last.... :wink: :roll: ). Even so, if it assists above 15mph (as it may well do depending on gearing if it is only cadence-sensitive) it would be illegal in the UK (yes, all two grand's worth of lightly recycled cordless drill.... :roll: ). Remember that the OP is regarding a 300W high speed (i.e. not legal in the UK) system with no pedalling; I suspect such a system will be heavy, expensive, or both.

I don't think you need fear the increased windchill either if you are in the habit of wearing clothes. Presumably, if you were to find an icicle forming on the end of your nose, you could always turn off the electrical assist, and then you would become hotter than on a normal bike because you are lugging around a doubly heavy object at a lower than usual speed. Perhaps you could factor in the cost of a nose warmer when you purchase your electric conversion kit?


Very good... :lol: But it'd take more than that.... having done a fair amount of winter motorcycling/cycling, I know that without exertion (as per the OP) you need to dress up like the michelin man if you are not to get hypothermia, freeze your 'nads off, etc etc. I've nearly died through cold; it is not to be underestimated.

cheers
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[XAP]Bob
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Re: electric bike kits

Postby [XAP]Bob » 17 Aug 2013, 11:52am

Brucey doesn't seem to like e bikes..

A colleague, who is somewhat overweight, regularly commutes the 12 miles each way...
He has a front wheel motor and uses RC helicopter batteries, about a kilo of batteries gives him 4-5 days commuting.

the ICE e-kit was awesome on test - not a significant added effort, no added effort when not in use (slight extra weight) and with a 27 speed at the rear it would do very nicely.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.