Adding a motor to my trike

Joined
Nov 22, 2021
Messages
9
Location
Southampton, UK
Hi,
I've just finished my Warrior Trike and it's a lot of fun. The problem is since it is made out of steel, it's pretty heavy and in the lowest gear it is hard work on the hills. So I was thinking of an upgrade via a rear wheel e-bike conversion. Anyone know any good sites, blogs, plan or general advice on fitting these.
Thanks
Tim
 
Joined
Oct 19, 2012
Messages
2,384
Location
Wakefield, UK
The rear wheel motor is the simplest and cheapest solution but a better one, imo, is the crank mounted motor. A TSDZ2 or Bafang would be the choice there. I have both rear wheel and crank mounted motors and the crank mounted is just nicer to use. The wheel and the Bafang crank motors use a sensor on the pedals that merely require the pedals to go round without effort for the motor to kick in whereas the TSDZ2 uses a torque sensor to kick the motor in so you actually have to pedal to get assistance. The motor kicking in when you are simply moving from coasting to pedalling is one I don't personally like. I prefer the motor to kick in only once my feet are firmly pedalling. It's purely my preference and not a fact that that system is better. I have two TSDZ2 units and got them both from here...
another good source for kits is...
A crank drive can use the torque multiplication effect of the gears whereas a wheel motor can not. If you opt for an ebay rear wheel then get one that has a display as the motor effort is controlled from the display (as are almost all motors). Get the displayless models and you get a non adjustable motor. I advise you to pay extra for waterproof connectors too. Basic ebay kits are not waterproof. You want julet or higo type connectors. If you get one with a throttle, apart from being non legal there is the possibility you rely on it and drain the battery much quicker. Whatever you go for keep under 1000W (only 250W is road legal). 1000W will propel you to 30mph and that's plenty fast enough for bike components. My TSDZ2s are 750W and will propel me at 25mph easily. If I upped the gearing they'd hit 30mph on the flat but I need the lower gearing for hills.

As to batteries you need to match the battery to the motor and your desired distance requirements. A 48V motor at 1000W will require a 20 amp draw so you need a battery with a BMS that will output a continuous 20A or better. If you get one that is less then the BMS will limit the motor to what the battery can supply to protect the battery from damage. A battery will have two amp ratings, one in AH which is a measure of the overall power it can put out until empty and one in amps which is the max output at any given time. AH will determine your distance and amps will determine what size motor it will drive fully.

Most motors come with brake levers that cut the motor out instantly. If you don't use them then many motors run on for a half second or so after stopping demand. I have never found this to be a problem and wouldn't worry about not having such levers.
 
Joined
Feb 7, 2008
Messages
4,572
Location
Nottinghamshire England
Hi,
I've just finished my Warrior Trike and it's a lot of fun. The problem is since it is made out of steel, it's pretty heavy and in the lowest gear it is hard work on the hills.
Thanks
Tim
Ok so first thinks first ? LOWER THE GEARING !!!

Whether ultimately you chose to add electric assist or not you really need to be geared to easily get up the steepest hill.

If not you may well damage your knees struggling up hills.

And you will be out on it when the electrics let you down and will have to pedal it home !

Paul
 
Joined
Nov 20, 2022
Messages
23
Location
West Virginia, USA
Only a single chainring on mid drive motors, correct. Because of the width, placement of motor and gearbox, there generally isn’t room for more. That’s not to say someone somewhere hasn’t done it.
The thinking is that the extra torque from the electric assist removes the need for more gears.
 
Joined
Jan 16, 2011
Messages
712
Location
Vilvoorde / Flanders / Belgium
I have build a double front chainring for my Bafang, and rebuild a front derailer. No biggy.

But it requires some creative thinking and advanced tool-skills.

And for a non assist, with a trike you can' gear low enough. The only reason the gearing on an upwrong is limited, is the fact you go face down when "too slow".
With a trike you can have any kind of lowest gear ratio.
 
Joined
May 31, 2013
Messages
3,980
Location
South Benfleet, Essex, England, UK
Like many others I Bafang'd my ride and put a non-standard spider on it with 2 rings and "customised" a front derailleur.
Not too hard to do and it certainly saved my knees from grief. :)
 
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