A legal question or two....

[Jeremy]

Sounds fair enough to me, 30mph is too fast in some urban areas. We have a few experimental 20mph limits here and they do seem to work. For some reason a 20mph speed limit seems to be complied with more often than a 30mph one.

I've just spent a happy hour or so reading regulations, clear they are not........

The pedal one is particularly unclear, as all that is required is that the pedals are able to propel the bike. There's no mention of direct drive, so provided auxiliary pedals connected to a generator could make the bike move, then the thing should be legal.

I agree about the EU Vs. UK legislation mix-up, although I thought we were still exempted from needing pedelec here? Don't the EU require pedelec, rather than throttle, control?

Jeremy

 

[flecc]

I agree about the EU Vs. UK legislation mix-up, although I thought we were still exempted from needing pedelec here? Don't the EU require pedelec, rather than throttle, control?

Jeremy

Sort of exempt by default, since our old law is still in force as I said, and that permits throttle only. There's signs that won't last though as I remarked about the Royal Mail move. If a test case was brought on the pedelec issue, I'm sure we woud lose out since the European order is clearly supposed to be the only one in force.

Throttles are permitted in conjunction with pedelec in Europe, but not in isolation without pedalling.

I'm sure you are right about using the pedals via a generator to motor drive, one prototype at least already existing.

 

[Ian]

I'm sure you are right about using the pedals via a generator to motor drive, one prototype at least already existing.

I saw such a device in an army surplus store recently, except it had no wheels. I think the idea was for a furiously pedaling private to power the radio gear.

 

[flecc]

I saw somewhere a bike generator to motor setup which was seriously intended and in development with patents applied for. The generator was built into the bottom bracket. I've a vague idea that it was antipodean, but can't remember the exact details.

I can't see any advantage, the efficiency at best being way below any cycle drive, including shaft.
.

 

[Miles]

I think flecc was refering to this, no?
http://mypage.bluewin.ch/fuchsbau/Fuchs2006.pdf

 

[flecc]

That's yet another one Miles, so there's at least two attempts now!

Still can't see the efficiency being acceptable as a pedal drive though.
.

 

[Miles]

I think it has advantages that can outweigh its relative inefficiency, for certain applications... It's a long time since I read it all. The best exposition is in the published proceedings of the 4th velomobile seminar, I think.
4th-eu-Symp

 

[Miles]

Here's something from the archive:
Ecomotion Design Harald Kutze

 

[flecc]

Thanks Miles, interesting.

That last one is actually even more inefficient by a very large margin, but the battery putting in the compensation of course.

Some amusing aspects. The statement that bicycles are small quantity local manufacture would shock Giant executives and a few other manufacturers, and their idea of an efficient bicycle design is so far off the mark I wouldn't know where to start in tearing it to pieces. The thought of pedalling that thing makes me shudder.

I always think it strange how people with inventions so often assume that because basic bicycle design was largely finalised a long time ago, it has to flawed and capable of big improvement.
.

 

[pxr5]

the law says you cannot have a motor and power source that combined propel you faster than 14mph, but you can pedal to go faster than 14mph, BUT almost every electric bike i see on sale says it can do the legal 14mph or flick a switch for off road speeds of 30mph, so surely they cant be legal cos the onboard power exceeds 14 mph?

 

[Ian]

Hello and welcome pxr5

The maximum allowed powered speed in the EU (which includes the UK) is 25kph or 15.5mph. A very small number can manage 22mph but not at the flick of a switch, a physical modification is required which then renders the bike illegal for on road use. I know of no freely available bikes capable of anywhere near 30 mph other than electric scooters and mopeds which are covered by motor vehicle legislation and require registration, insurance, helmet etc.

 

[pxr5]

Hello and welcome pxr5

The maximum allowed powered speed in the EU (which includes the UK) is 25kph or 15.5mph. A very small number can manage 22mph but not at the flick of a switch, a physical modification is required which then renders the bike illegal for on road use. I know of no freely available bikes capable of anywhere near 30 mph other than electric scooters and mopeds which are covered by motor vehicle legislation and require registration, insurance, helmet etc.

Hi Ian thanks mate.

sorry im new to the idea of getting a conversion kit for my bike and ive looked at the options including a 48cc 2 stroke engine which can do 30mph and obviously got my wires crossed.
so basically i should totally avoid those things just stick with something legal, in that case id love to build my own, maybe use a cordless drill or something like that lol

 

[Ian]

I've seen 2 stroke petrol engine conversions on ebay, confusing as they often include the words electric bike so they they show up in searches. They are highly illegal and I think the noise and smoke would soon attract attention.

Don't knock the cordless drill idea, I'm sure it's been done.

 

[DBCohen]

Hi Ian thanks mate.

sorry im new to the idea of getting a conversion kit for my bike and ive looked at the options including a 48cc 2 stroke engine which can do 30mph and obviously got my wires crossed.

Any additional motile system added to a bike adds to the weight and potentially affects the bike's balance. Quite apart from the legality, I would have thought the addition of the mass of a petrol engine plus fuel would make the bike pretty unmanageable when not using the engine - and if you have to use the engine all of the time to negate that weight, then you might as well get a purpose built engine-powered machine such as a moped.

 

[ITSPETEINIT]

Petrol engines on bikes

Hi Ian thanks mate.

sorry im new to the idea of getting a conversion kit for my bike and ive looked at the options including a 48cc 2 stroke engine which can do 30mph and obviously got my wires crossed.
so basically i should totally avoid those things just stick with something legal, in that case id love to build my own, maybe use a cordless drill or something like that lol

I had a 35cc Korean (North or South?) 2 stroke engine on a Mountain Bike. It lasted 1500 miles before it fell apart.
They are not that heavy - the motor about 5Kg. Petrol/oil consumption was about 23miles/litre, but extra fuel is much lighter than a spare battery mile for mile.
The upside is they are great fun - 25 mph @ 7000rpm: automatic clutch: lots of fresh air (like an electric bike).
The downside is: They are noisy: they vibrate like mad: fuelling-up is a messy job: there is a worrying absence of drive when the road is wet/damp (if it's a friction drive on the tyre) and none at all on damp hills: Road Tax: Insurance: MOT: Crash Hat (though I always wore one even on a pedal bike after I fell off and head-butted the road - and survived): Number Plate.
The auto clutch was crude; the limit stops when the clutch disengaged were little rubber washers which soon degenerated and then the pegs on which they were fitted took the knocks until they broke off - DISASTER!!
The marvellous expanding pulley, which gave the motor a sort of gearing, was carried on a plastic sleeve over the drive shaft which degenerated very quickly. I had slipping drive belt problems (I could not get the correct drive belt in the UK) and I never did discover where all the aluminium powder that appeared in the crankcase was coming from.
And Piston rings were not what they should have been.
Retrofitting to a pedal bike is not easy: the critical tolerances between seat tube and tyre were small - I had to fit 2.5 inch tyres to 'get a grip'.
The suppliers in the UK are worse that the worst of e-bike suppliers (that's if they exist) when it comes to service.
You would need to be a clairvoyant to anticipate the aggro you will get. You will never get enough honest answers to make the 'fit-for-purpose' judgement.
BUT if you want a lesson in how 2 stroke motors work and are a bit of a 'pioneer' then they are just the job!
Have you seen Staton-Inc motorized bicycles bike kits gear drive kits. ?
An American company that does motor kits for bikes including a gearbox, based upon a Honda GX31 Strimmer Motor. It's a very interesting site - there was (can't find it now) a recumbent biker who modified his bike/trike using that stuff and it really did look the business. You could buy a proper motorbike but you'd lose the fun and pride of making your own.
Peter

 

[Miles]

Further to Peter's post:

http://www.users.globalnet.co.uk/~pattle/nacc/arc0497.htm

Golden Eagle Bike Engines, Geared Belt Drive Bicycle Engines / Motors for Mountain Bikes & More

It's not a direction that interests me, though.....

 

[pxr5]

well thats that idea out of the window then lol. ive seen those links before thanks. i really like this drill idea but it sounds very noisy.

 

[Miles]

DPX Systems Product Details

 

[Jeremy]

The idea of a hybrid bike is interesting. I drive a hybrid car and find that it gives some of the advantages of a pure electric drive, but provides decent range from the petrol engine.

I've spotted this : Endless-sphere.com :: View topic - Micro Diesel Generator and have been looking closely at whether an automatic, very quiet, micro-generator, coupled to a modest capacity battery on an electric assist (not outright electric powered) bike might not be a reasonably feasible concept.

Small four stroke engines weighing less than 3kg are now readily available (the Honda GX25, for example). The pull start could be removed to save a bit of weight, the bare engine coupled directly to a high-speed electric motor/generator, the whole unit wired to an intelligent controller that could start/stop the generator as required based on battery state of charge and then the whole thing enclosed in a sound insulating enclosure.

I believe that it should be possible to build a small (around 300W - 400W) generator that would be compact enough to easily fit on a bike. Looking at motor weights, I think that it might even be possible to build a combined generator/lithium battery hybrid power supply for around the same weight as present day NiMH pack of average capacity, but with perhaps ten or more times the range.

The idea of a quiet, relatively clean, long range power assisted bike is quite appealing, particularly if the system could be made legal for fitment to a bike within the present regulations.

Jeremy

 

[Miles]

The idea of a quiet, relatively clean, long range power assisted bike is quite appealing, particularly if the system could be made legal for fitment to a bike within the present regulations.

Jeremy

That's the problem, it could only be legal if you got SVA and registered it as a moped....