In many states there is a limit to the speed a pedal assisted motorized
bicycle can legally achieve on level ground. 20mph is common. What you can
hit on a downhill is not considered.

You will find it difficult to get gearing that will provide a 30mph top
speed and allow enough torque at a standstill to start off with even the
slightest incline.  Since you are a fairly heavy pilot (and with the added
battery weight) this will be additionally difficult. You will have some
trouble finding hub motors (wherever you actually mount them, these are
your better choices) with useful gearing and that can take repeated
application of starting torque from you and the motor together.  Starting
off is you worst condition structurally.

I think you want to investigate RC controller electronics (Kelley has stuff
that works). You did not say what sort of range you wish. A reasonable
starting point might be 10 miles on a charge. I was commuting 25 miles each
way with an Organic Transit ELF for a year. Battery-ing up for that was
costly. The ELF is a lot heavier due to substantial body work. Remember not
to let fully charged Li-ion cells too get hot.  Don't charge in the hot sun
and leave it all sitting out to broil.  It will ruin the cells, LiFePo
particularly. 100F or less only when fully charged.

As trike user, I always thought a trailer with a pusher motor would bee a
good arrangement. It allows you to dispense with the electric drive when
that makes sense. You will have an easier time creating an experimental
test chassis and battery mounting means if it is not stuck onto a severely
space constrained and less than heartily built compact tricycle.

Also the system can be switch from trike to trike or bike.

I say this with significant knowledge of recumbent trike design.  I own a
Greenspeed touring trike (20003 vintage GTO) which is considerably larger
and stouter than a Terratrike.

I would also advocate a streamlined tailbox of some sort to improve drag. A
front fairing provides less improvement for the cost and effort compared to
a tail box. Full streamlining is of course the best solution.  People have
maintained 45mph hour speeds for an hour with a good full fairing (level

I have been to SF where I believe you live. Respectfully and as one who
used to ride off weighing 250 pounds, I think will be disappointed with how
a recumbent trike functions with the steep grades you will encounter (until
you reduce your body weight below 200 pounds or less).  Even then it will
be quite strenuous and at time daunting.

There a folks in CA that have done a lot of the ground work for this.  You
would get ahead meeting and cultivating them. William Patterson  at UC
Irvine or Davis, I forget, used to teach ME classes on single track
recumbent design. Those classes spawned a host of smart recumbent builders.

Good luck.

On Sun, May 28, 2017 at 3:19 PM, Russ Sciville via EV <>

> I can vouch for the Lynch motor as I use one on my ride on mower.Using
> three 90Ah 12v Pb cells it easily cuts for 20 minutes or more at time.
> A brilliantly simple but powerful design and I have even met the guy who
> designed it.
>       From: Lee Hart via EV <>
>  To: Lawrence Rhodes <>; Electric Vehicle
> Discussion List <>
>  Sent: Sunday, 28 May 2017, 20:09
>  Subject: Re: [EVDL] Most efficient drive system for a bicycle/tricycle.
> Lawrence Rhodes via EV wrote:
> > I'm looking at options for my Terratrike.  Mid vs hub seems to be the
> thing.
> > Seems bike systems are only 80% efficient.  Has any one had good success
> with
> > efficiency as well as speed.  I'm looking to top out at 30mph with a 20
> inch
> > wheel. Is voltage an issue?  I'd like to keep it to 48vdc but I'm
> willing to
> > go higher or lower if it is an advantage(money or performance).  I will
> > eventually have a shell with solar panels...
> Maybe a Lynch motor (Lynch, Lemco, Etek, AGNI, etc.)? They are over 90%
> efficient, and being a DC motor, can be switched straight to the battery
> for no
> controller losses. Rig a series/parallel setup with switches or relays to
> get
> 12v/24v/48v for speed control; that's also essentially 100% efficient.
> --
> Any intelligent fool can make things bigger, more complex, and more
> violent. It takes a touch of genius, and a lot of courage, to move
> in the opposite direction. -- Albert Einstein
> --
> Lee Hart, 814 8th Ave N, Sartell MN 56377,
> _______________________________________________
> Read EVAngel's EV News at
> Please discuss EV drag racing at NEDRA (
> group/NEDRA)
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