Twin motors, Generator, Hub Motor Twist

[flecc]

Three subjects that regularly crop up are these:

Using twin motors on an e-bike.

Having a generator on board.

Adapting a failed Lafree Twist to a hub motor.

Well here's a bike that has all three elements incorporated, originally seen and photographed two and a half years ago in Derbyshire:

It's actually a fully working Lafree Twist with an added Heinzmann hub motor in the front forks. Both motors separately and individually use the battery built in to the Twist's Panasonic power unit, but with the generator that's mounted on the carrier, both motors can run together at the same time giving two wheel drive.

Together with pedalling only, that's a four way choice of travel mode.

Petrol consumption with all on is roughly 450 mpg with 240 watts generation. The weight with petrol is 36 kilos, still much less than a typical SLA battery single motor model like the Powabyke.

If the Heinzmann was chosen as the high speed version, there'd be the combination of the Twist's normal slow hill climbing abilities, a 19 mph fast mode using the hub motor, and high speed hill climbing with all systems on.

The Nano would be another suitable motor, and that would match the quietness of the Lafree's unit.

All great fun of course, but very illegal.
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[subevo]

i was thinking of transfering the complete front end from my eeze liv to the twist.do you think it would mechanically fit.what are the required steps to remove the front fork assembly.im good with cars but not with bikes.

 

[BossBob]

Nice post Flecc ..... very cool setup

All great fun of course, but very illegal.
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But is it?
It is illegal if you want to call it a bicycle, but, what if it were to be "registered" exactly as it is, probably needs a DOT engineers report, a number plate and of course the dreaded "tax" but it could still be a very viable form of transport done right. Road tax is now done on emissions and a Peugot 206 is a measley £35 a year. It couldn't really cost that much for an electric bike.

You could of course go 2 steps further, a rear hub motor and a curries spoke drive, with all 4 on for the hills it should fly up them

Ok .... I'll stop dreaming

 

[flecc]

i was thinking of transfering the complete front end from my eeze liv to the twist.do you think it would mechanically fit.what are the required steps to remove the front fork assembly.im good with cars but not with bikes.

You'll need a good dealers help with that. The headstock is the same type, but the Liv stem would probably need shortening and re-threading, only for a suitably skilled dealer with the right tools. No reason against otherwise, though best only on the gents crossbar Twist, not the step through which has too much frame flex for the powerful Liv drive.

P.S. Rechecking, the stem might be around the right length, but I'd still get a dealers measurement and opinion first if I were you, just to check that all factors were ok.
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[flecc]

Nice post Flecc ..... very cool setup


But is it?
It is illegal if you want to call it a bicycle, but, what if it were to be "registered" exactly as it is, probably needs a DOT engineers report, a number plate and of course the dreaded "tax" but it could still be a very viable form of transport done right. Road tax is now done on emissions and a Peugot 206 is a measley £35 a year. It couldn't really cost that much for an electric bike.

You could of course go 2 steps further, a rear hub motor and a curries spoke drive, with all 4 on for the hills it should fly up them

Ok .... I'll stop dreaming

Of course Bob, possibly ok as a motor vehicle, though I think the brakes would have to be very much better to get approval.

I was referring to that one being illegal, as it wasn't registered.

Unfortunately the Twist can't have the Currie drive as well, no spoke block being made for hub gears, a long standing complaint.
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[subevo]

hi flecc,mine is the gents version with the cross bar .i might take it all apart and have a look.also how does the generator work? is it supplying 240v then reduced to 24 or 36v? more details please if possible.

 

[Jeremy]

At least one person has built a small DC generator using the little tiny 3.5kg Honda four stroke engine. It looks quite simple, just a direct drive (via the centrifugal clutch on the end of the Honda GX25 or GX35 engine) to a suitably sized permanent magnet motor, working as a generator. All you need is a modest power output from the generator, if you're using it to charge a set of spare batteries (which, it could be argued, might well be legal). I believe that a generator output of around 300 watts should be enough to charge a spare battery before the battery in use runs out.

The system just needs a change over switch, to isolate the battery being charged from the bike. This way it could be argued that the bike is only ever powered by the battery that isn't connected to the generator, so technically I think this would mean that it still falls within the power assisted bike rules.

Jeremy

 

[Ian]

What a neat little engine that GX25 is, I wonder how noisy it is, it is described as having a "pleasing low tone" although no figures are given.

 

[flecc]

Yes it's a beauty. Their smallest encased generator, the 900 watt one, has a noise measurement of 52 dB at seven metres I believe, so this is probably quiet.

I have few details on that outfit Subevo, so no idea of the generator arrangements. A lot of work involved in such a conversion, I'd rather have the lower weight and better balance of a pair of pannier mounted additional batteries. Might be just as cheap too, and with tripled range.

I've already done that in Summer on two of my bikes.
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[subevo]

today i removed the motor wheel from the ezee liv and with the aid of new homemade brackets fitted it to my giant lafree.i mounted the battery on the lafree rear rack ,switched it on and yehaa it all worked.going to test it by going to work tomorrow.ill report back.

 

[subevo]

pleased with new set up.with both drives working and me pedaling hills are now a breeze. with the old lafree set up it copes with most small -medium hills in top gear.harder hills you have to drop down gears.but now i can keep it in top for all but the steepest of hills.the last hill on the way home is a killer with the old lafree dropping to first gear.today with my 4 gears i was in third and it was comfortable.downsides are its a heavy beast now.it nearly tips over on the side stand.also ive no front brakes at the moment as the lafree wheel had roller brakes.the best solution is to transplant the complete front end from the ezee liv but the steering stem on the liv is about 20mm too short and a different diameter. can the stems be pressed out and another fitted or swapped over?this way i would have brakes.

 

[flecc]

Well done on getting it running on both motors. I doubt if the stem can be pressed out, I've never heard of it being done but an engineering company may be prepared to try it. I was a bit surprised that the Liv stem was shorter, but I could only guess at it from different photos.

I don't know the Liv motor width, but it might be worth checking if new forks could be supplied that suit, as there's several reasonably priced makes around. The eZee bikes usually use Zoom forks, and Shox are another low priced make.
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[subevo]

the liv forks are 125mm wide at the spindle.i will strip the lafree forks and compare the stems.i wonder how the stems are secured to the yolk looks like a press fit possibly crimped at the bottom.wheres the best place to find a set of forks with 125mm width.the liv stem is 195mm long . the frame housing is 175mm.the lafree frame housing is 195mm so the stem is probably 215mm.

 

[flecc]

I don't know of anywhere to get wide forks, not something I've ever tried to source.

Have a word with the cycle engineering company Highpath Engineering

phone / fax: +44 (0)1570 470035 (UK office hours only)

email: admin@highpath.net

Chris Bell there may be able to help with conversion of your Liv forks so that they suit the Lafree.
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[subevo]

fixed it .the complete front end of the liv is now on the lafree.the lafree steering tube is 1- 1/4" diameter.the liv is 1-1/8." the two tubes are a neat sliding fit into each other. so i cut the old tube off the lafree and secured it to the liv tube. then re-assembled. wasnt quite as easy due to different wall thickness of the lafree tube at the bottom bearing.3 hours of hand file work .if i had a lathe 5 minutes.job done.happy again.now that ive experienced twin motor bikes.i think it would be good if a manufacturer offered it as an option.

 

[flecc]

Well done Subevo, sounds like nice job, greatly increasing the usefulness of the Lafree.

I'd wondered if one tube might fit into the other when you mentioned the different sizes before, but thought no-one could be so lucky!

There's nothing better than having a unique personal bike, even though there's a load of work to create it. It's the legal problems that hold back the manufacturers of course, the 250 watt limit again.
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