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Electric assist fitted to pedicabs
Posted: 05 Dec 2008, 08:35
by adam2
Sounds quite a good idea to me, though it is alleged to be dangerous.
http://news.bbc.co.uk/1/hi/england/london/7766458.stm
Such low tech, low power electric assisted vehicles, may have a great future.
The energy used does of course have to come from somwhere, but the amounts used are very modest.
Many such pedicabs, electricly assisted or otherwise, are ridden somewhat irresponsibly, but the answer to that is surely to prosecute the worst offenders, not to ban the vehicles.
And the police state that "its only a matter of time until someone is killed or seriously injured by one these vehicles"
No doubt true, but it also means that despite the widespread use of these contraptions, no one has yet been killed or badly hurt. This might suggest that the risks are not in fact that great.
"Proper" large heavy motor vehicles kill thousands every year, and no one worries about that!
Posted: 05 Dec 2008, 08:51
by DominicJ
Farm more car miles than pedicab miles, these are illegaly modified and uninsured, people have been killed after being hit by cyclists, meh, the usual really.
I did look at buying and modifying one, but for what they are, currently they are stupidly expensive.
Which is a shame.
***
By "Modify" I wanted to replace the battery with two large deepcycles in place of the panniers, not sure how the weight would handle, but I suppose me and two batteries must weigh less than a fat(ter) person.
20 mile range is standard, in chinese miles.
Posted: 05 Dec 2008, 11:14
by PS_RalphW
Electric assist velomobiles are legal and do not require insurance, although it is available. They are (more) common in europe, specially Holland.
The commercial ones are expensive and are not dangerous if ridden responsibly, which is far easier in Holland than here. Velomobiles can cruise at 30mph WITHOUT electric assist.
Range is a factor of how much you pedal. At the top end is the Twike, really a low end electric car with optional pedals.
Costs are high because volume is miniscule. Self -build is a lot cheaper.
Posted: 05 Dec 2008, 11:17
by PS_RalphW
ps. I confidently predict it will be only a matter of hours or even minutes before somebody is killed by one of those dangerous motorised contraptions being driven irresponsibly, and I don't mean something with pedals.
Posted: 05 Dec 2008, 11:20
by PS_RalphW
Oh and far more people are killed and injured by uninsured car drivers than by uninsured cyclists/peddlers.
I'm feeling combative today
Posted: 05 Dec 2008, 11:37
by DominicJ
Electric assist velomobiles are legal and do not require insurance,
These are not EAV's though, because EAV's have a legaly mandated speed limit, 12mph I think.
These go 20mph.
They are therefore just illegal roadgoing vehicles.
Oh and far more people are killed and injured by uninsured car drivers than by uninsured cyclists/peddlers.
I did not say they were not, simply that there are a lot more car miles driven than EAV miles rode.
Despite there being 9-10 fatalities a day on Britians roads, we have some of the safest roads in the world, per car mile driven.
Posted: 05 Dec 2008, 12:13
by PS_RalphW
15mph
Edit - I cycle at speeds upto 20mph every day - quite legally
Posted: 05 Dec 2008, 13:48
by DominicJ
But not under electrical power.
Posted: 05 Dec 2008, 14:17
by skeptik
RalphW wrote:15mph
Edit - I cycle at speeds upto 20mph every day - quite legally
If you had two passengers sitting on your back rack what would be your stopping distance on a wet road at 20mph? ( you can have a third wheel at the back if you fancy)
Posted: 05 Dec 2008, 15:25
by PS_RalphW
skeptik wrote:
If you had two passengers sitting on your back rack what would be your stopping distance on a wet road at 20mph? ( you can have a third wheel at the back if you fancy)
OK
This is impossible to answer exactly - far too many variables. But I could guestimate the relative stopping distances between the two vehicles under the same conditions.
If you will allow me 3 wheels and disk or hub brakes all round, then the brakes will be unaffected by rain, and quite powerful enough to lock the wheels.
So the stopping distance is related to the maximum deceleration I can provide without locking the wheels in the wet. With about 3 times the mass to decelerate, and one extra wheel, and using
F = MA and d = UT + 1/2 AT squared
so the deceleration would be about half that on by bicycle, so the time to come to a halt would double, and d would be about 4 times larger.
Of course, that is deceleration time, reaction time and distance would be unaffected.
Also, if it was a sensible design, it would have wider tyres. If they were twice as wide then the maximum friction force would be about double, and with the extra wheel the stopping distance would be shorter.
It's all in the details...
Posted: 05 Dec 2008, 19:50
by RenewableCandy
I'm not sure what kind of wheels this thread is talking about: anyone care to put up a picture??
Posted: 18 Dec 2008, 08:52
by adam2
RenewableCandy wrote:I'm not sure what kind of wheels this thread is talking about: anyone care to put up a picture??
There is a not very good picture in the link in the first post, and other pictures in the links from the link.
Designs vary a bit, but most consist of a single front wheel and two rear wheels.
The driver sits on a cycle saddle and pedals, with a chain drive to the rear wheels.
Cycle type hand operated brakes are usually fitted, working on the wheel rims, some better designs use disc brakes, but this is rare.
A bench seat for the passenger(s) is located over the rear wheels, and is often covered by a canopy or awning for weather protection.
Seat belts are sometimes fitted, but not normally.
Power assistance if fitted, is generally a vehicle battery located under the seat, and a 12 volt motor of about a half horsepower, driving the rear wheels by a belt. Speed control is not usuall, the motor simply being on or off, and controlled by a switch on the handlebars.
A few types use two motors or two batteries and series/parralell switching to give two speeds, such sophistication is rare though.
The fares are substantial, often more than a licensed taxi would charge for the same journey, more of a tourist trap than an everyday means of transport.
I have seen such vehicles being used for delivering parcels and light freight, but this is not the norm.
Posted: 19 Dec 2008, 20:42
by mikepepler
We've been riding our
leccy bikes to the wood for a few months now
I'm pleased we spent the money buying decent ones, I think they're probably a lot lighter and more effective than a modified bike or other vehicle. It feels a bit lazy as it's only 5.5 miles, but it's hilly, we have about 10kg in the panniers and after cutting trees all day I don't think I'd fancy the ride home unassisted, and would just end up driving instead.
Posted: 10 Aug 2009, 15:51
by Bugbugs
skeptik wrote:RalphW wrote:15mph
Edit - I cycle at speeds upto 20mph every day - quite legally
If you had two passengers sitting on your back rack what would be your stopping distance on a wet road at 20mph? ( you can have a third wheel at the back if you fancy)
We actually had an unpowered pedicab tested by the PCO (public carriage office) and they actually had the same stopping ability as a car. At bugbugs, even though we never operated any electric assisted pedicabs for hire, we even managed to get one through VOSA single vehicle approval as a low powered moped. Hope that helps any potential switchers make up their mind.
We even have a proto type -legal- electric assisted which comes on the scale's at just under 60kg so not a problem as a cycle, though still not advisable as a 'ply-for-hire'.
Posted: 10 Aug 2009, 16:36
by adam2
I consider that the vehicles refered to are more of a tourist attraction, than a serious mode of daily transport, still to be encouraged though, since at the very least they raise awareness of non FF powered vehicles.
IMHO it is a pity that such technology has been given a bad press by the foolhardy way in which such vehicles are ridden, and by a few well publicised cases of gross overcharging.
The London licensed taxi trade hates pedicabs, electricly assisted or otherwise.
Any idea that such vehicles should be licensed is like a red rag to a bull !
I believe that they should be licensed, required to have insurance, and be fitted with taxi-meters if they are to convey the public.
For private use, I feel licensing is OTT provided they cant exceed say 20 MPH, if capable of higher speeds then insurance should be required, and perhaps also an MOT.
Although not YET a serious mode of transport, I can forsee the day when pedicabs will at least partialy replace both taxis and light vans, for shorter trips.