A e-Trike project

[grldtnr]

I have a Tadpole config recumbent trike sitting at home doing nothing much ( 2 wheels front ,1 rear), easiest way of converting it would be to put a rear hub drive into it, which I don't want to do,

Had a think about it , there are 2 options , it has 20'' front wheels with drum brakes ,bung a 2 front hub drives on to the chassis with disc brakes, a potential problem is that the wheels are simply bolted , not mounted on a axle as such, works fine tho' this would give me 3 wheel drive with the rear wheel being the original chain driven one .

The other option is to fit a bottom bkt motor ,the trike has a chainset mounted on a boom with a very long chain to the rear it takes 2 1/2 chains, but it has a further bottom bkt assembly under the seat as part of the frame ,which is threaded and blanked off ,this may be the best place to mount a ctr motor. maybe it would be possible to put a crossover drive ala Tandem, from the front to the under seat motor,I have spare bits to do that .

Do any of self builders see problems doing that?
Or maybe D8veh
Another thought is to put 5 , yes FIVE motors onto it, one in each wheel and 2 centre motors, should pull like stink but maybe not get very far!

 

[oigoi]

Have you seen the cyclone mid drive motors?

http://www.cyclone-uk.com/

 

[eHomer]

I converted my Hase Lepus delta trike with a Q100H 328rpm motor in the single front wheel and it was a great success.

For the same reasons that recumbents are more efficient to pedal, they make better use of electric power, because of the much lower wind resistance etc..

Personally I'd avoid putting in more than one motor, recumbents really do give the chance of a very lightweight but powerful combination without detracting the human power flexibility, you get a very good compromise out of them.

Even the tiny Q100H motor easily gets my Hase up to 20mph, though it ambles along easily at 15, with a range of about 30 miles with 10ah of 36 volts.

I think if mine was tadpole config I'd try a BBS01 350 watt, mounted in the existing bottom bracket shell.

 

[grldtnr]

My preference would be to mount a BBS01 In the Bottom bkt shell under the seat, then have a tandem X-over drive from the front, but would there be enough room to mount a tandem pick up drive on the LH side?

had problems with not getting enough grip from the single wheel in some conditions, having twin front wheel power would solve that, The idea of putting 5 motors on would be a bit fancifull, I haven'tthat much money!

The trike is a Crystal Ross, maybe nearly 20 yrs vintage, now built as ICE recumbents

 

[eHomer]

I agree, it is easy to get front wheel spin on loose gravel from a standstill, but I always ride "assisted", so my Delta trike is then two wheel drive (front and right rear), and I never have problems then on any surface.

If I were to just use throttle only, yes the single front wheel drive could be tricky on poor surfaces, as there's so little weight on it.

 

[Cyclezee]

Hi grldtnr,

Just wondering what you have against a rear hub motor for your tadpole recumbent.

My first conversion a few years back was the same configuration and an absolute blast.

 

[Geebee]

I am expecting my BBS01 today (fingers crossed) to fit to the boom on my recumbent trike, it is possible to fit 2 rings on them with an adapter, they end up making for a lightish weight conversion as you remove ~1kg of bits off the trike before you begin.
EDIT: BBS01 arrived and all up weight is around 19.5 kg with battery ready to ride was hoping for lighter, but that does include the newly fitted rear rack and battery bag.

Re front wheel motors, you would need hubs designed for single sided axle support and with brakes, not common, trikes put massive side pressure on the front wheels.

Rear wheel traction is affected by gear inches as well as surface grip, if you muscle your way up a steep slope in a higher gear you will get wheel slip earlier than using a lower gear inch and spinning.
The crank drive or mid drive make more sense on trike as you can crawl up steep hills at speeds a bike would have trouble with.

If you use a mid drive your cranks will rotate with the motor unless you use a freewheeling crank or similar. A Crank drive is easiest and lightest with exceptional hill climbing ability.

 

[mfj197]

Geebee, sounds like you'll have fun. You say you remove ~1kg of bits from the trike before installation of the BBS01. I've seen the weight of the BBS01 quoted as 3.7kg - but is that just the motor, so crank arms, chainring etc. are on top of that? In other words are you putting back on much of the 1kg you have taken off?

grldtnr, as per Cyclezee I would have thought a rear hub would be rather more suitable than considering front hub motors. Is there a reason you're not keen on one (if going the hub route)?

Michael

 

[grldtnr]

Geebee, sounds like you'll have fun. You say you remove ~1kg of bits from the trike before installation of the BBS01. I've seen the weight of the BBS01 quoted as 3.7kg - but is that just the motor, so crank arms, chainring etc. are on top of that? In other words are you putting back on much of the 1kg you have taken off?

grldtnr, as per Cyclezee I would have thought a rear hub would be rather more suitable than considering front hub motors. Is there a reason you're not keen on one (if going the hub route)?

Michael

mainly because before I gave up serous cycling, I recently had a new handbuilt wheel made for the rear, seems a shame to junk it to put a machine built one in its place.
recumbent trikes dependant of config do have problems with drive wheels, on mine there is little weight over the wheel ,it sometimes loses grip, it seems it would be best to put a ctr drive on it , the best I reckon would be twin front wheel drive as you have in a conventional car, maybe it would solve the problem of the rear wheel sliding away when cornering briskly, but once you master the art is damn good fun drifting round bends, but wrecks wheels!

Trikes are machines that can be tamed but never mastered!

 

[mfj197]

I wouldn't junk the wheel, I'd have a hub motor laced into the wheel you have. Also if you had a motor in the rear wheel there would be more weight on it to retain traction too. I think I'd be hesitant of going the front hub route - there is potential for asymmetric thrust which would be a right pain on the wheels you use to steer with.

I'd love to try a trike - never tried a recumbent of any description!

 

[Geebee]

mainly because before I gave up serous cycling, I recently had a new handbuilt wheel made for the rear, seems a shame to junk it to put a machine built one in its place.
recumbent trikes dependant of config do have problems with drive wheels, on mine there is little weight over the wheel ,it sometimes loses grip, it seems it would be best to put a ctr drive on it , the best I reckon would be twin front wheel drive as you have in a conventional car, maybe it would solve the problem of the rear wheel sliding away when cornering briskly, but once you master the art is damn good fun drifting round bends, but wrecks wheels!

Trikes are machines that can be tamed but never mastered!

Do you have a photo of your trike?
If it is a front heavy as you describe I would avoid a crank drive as the weight out the front wont help handling.

My trikes are low and long so handling and rear traction is not an issue, Handling wise I like smaller wheels 20~16", one of my current trikes came with a 700c rear wheel, I wont ride on the road with that wheel, I either fit a 26" or 20" as the rear end flex is an issue if you like cornering at stupidly high speeds.
It might be worth trying that on your trike as it reclines the seat further putting more weight over the rear wheel and lowering the cg. and allows harder braking as the rear doesn't lift.

 

[grldtnr]

Do you have a photo of your trike?
If it is a front heavy as you describe I would avoid a crank drive as the weight out the front wont help handling.

My trikes are low and long so handling and rear traction is not an issue, Handling wise I like smaller wheels 20~16", one of my current trikes came with a 700c rear wheel, I wont ride on the road with that wheel, I either fit a 26" or 20" as the rear end flex is an issue if you like cornering at stupidly high speeds.
It might be worth trying that on your trike as it reclines the seat further putting more weight over the rear wheel and lowering the cg. and allows harder braking as the rear doesn't lift.

I don't have a pic to hand, since the trike is at the back of the shed behind other things! ,but it is not dissimilar to the Greenspeed, or if you know of them ICE trikes of Truro ,Cornwall, it would be considered the prototype before they refined the design,It has 20" front, 700c rear.

Bearing in mind the handling qualities of 'bent trikes ( indeed I did bend it spectacularly once on a Randonneur ride once, but managed to ride to the finish ,another 40miles!), I think the ctr motor out on the boom maybe best, 'coz as you know, cornering in a 3 wheel drift isn't going to last long with a rear wheel motor, hence the reason I had the rear wheel built!

That's not too say recumbents are hairy to ride ,just that the edge of handling is extreme when taken to the limit
You can do things on them that would not be possible on a solo cycle

 

[stevew]

Just fitted a rear hub motor to my ICE Classic NT with the help of D8veh's advice. If it's of any help i can do some piccies next week.

 

[grldtnr]

Just fitted a rear hub motor to my ICE Classic NT with the help of D8veh's advice. If it's of any help i can do some piccies next week.

would be very interested in that, please do!

 

[stevew]

OK i'll dig it out on Monday !!

 

[stevew]

Here we go, not a finished project yet, more work in progress !