E-trike for disabled youth

[JDPA]

I am a new poster, thank you for your interest in my post.

Short background. My very petite 11 y.o. daughter has an undiagnosed developmental disability that includes general muscle weakness. Try as she may (and her determination will get her far), she does not have the strength, balance, coordination to ride a two-wheeler. With training wheels she can participate if mom (me) or dad is there to help with a push or two. The co-pilot (tandem like trailer bike) we use is fantastic for family bike outings on the trails, but we want something she can independently enjoy around the neighborhood.

My thought is a pedal assist trike. The "medical" options I've found are cost prohibitive (+$2k), and we love to do projects. Having this for her for summer would be fabulous. I'm thinking of starting with a Worksman Port-O-Trike PTJR ($420 or better if I can find something used) and adding something to the front-hub that utilizes pedal sensors. I'd prefer that to a throttle so that there is one less thing for her to coordinate. She has the coordination and ability to pedal, just lacks the strength to get up slight hills.

However, I am a complete novice when it comes to the conversion. I would welcome suggestions on kits, frames, as well as past experiences. My husband and I are very creative and do lots of DIY. Electrical and mechanical doesn't concern us, we can handle that. Neither of us have welding experience.

Thank you again. -jd

 

[pelle242]

Get her a kmx storm or cyclone, a small geard hub motor like a cute in the rear wheel and some lipo and she will own the neighborhood.....

 

[Rassy]

I don't have any specific trike or motor recommendations, but when you do pick out a motor be sure to pick out one set up as a "slow" motor. For instance, a Bafang motor made for a 26" wheel runs slower than a Bafang motor made for a 20" wheel. So even if the motor is going into a smaller wheel you would probably want to specify the motor made for a 26" wheel to keep the top speed lower.

I disagree with the above poster. Get an easy to use and maintain battery, even an SLA. She will be able to keep it charged properly and other than the electrical issue all batteries have it is a very safe battery to use.

Be aware that children under 16 are not allowed to use electric assist bikes or trikes on public roads or trails in many USA states.

I also think she should have a throttle since getting going on a hill might be a problem with just a pedal first system.

 

[Drunkskunk]

Welcome to the forum.

The Worksman Port-O-Trike has 20" wheels, So I'd sugest a 36 volt 350 watt MXUS geared hub motor meant for a 26" bike, but have it laced into a 20" wheel instead. That motor can hit 20mph in a 26" wheel, but in a 20" wheel, it will top out at more reasonable speeds, and run more efficently at slower speeds. I'd also suggest changing out the pedal crank gear for a lower ration, to make it easier for her to pedal. I use that motor on a bike. its powerfull enough for an American sized adult, but small and light weight.

That motor is available from Cell_man's website: Emmisions_free.com. Or from several other places as well. The kit form does come with pedal assist sensor, but I'm less familure with how to set that up. Mine got dropped straight in the trash with the packaging, but others have used it and like it.

A 36 volt 10A lithium battery will take someone atleast 10 miles. with pedal assist and slower speeds, it will go farther. Emmisions_free.com is my first choice for recomending a battery too, but other sources are available.

 

[999zip999]

With a small movement of a peddle or adj. the peddles while turning the motor will jump forward. This can be a problem. Methods has a wife,s kit in the for section that is slower and for hills. With all motors there is a trade off as for speed or power. No lipo batteries please. Get a good plug and play battery. Alway's get more battery then you think you need as alot of vendors lie about them ( ebay ) ect. And you will have to pay twice and down time as the cheap ones break.

 

[teklektik]

Whoops - drunkskunk posted a similar recommendation while I was typing - I second his recommendations.
Here's my parallel typing effort

An ES member cell_man has a web site and business in China and sells good stuff. He is well respected here.

You might pick up a 350W torque wind front MAC or MXUS 350W gear motor from him along with a controller and 36v LiFePO battery+charger. Get as much amp hours in the battery as you can afford to make her day tripping as long as possible - with the basket on the back, weight is not an issue (SLA batteries would work but you will shortly be unhappy with short runs and replacements). Email him and explain your situation - he will try to put something together that will meet your needs. You could get parts from various sources, but this would be a one-stop-shop to save on shipping and ease support issues.

If in your budget, get a Cycle Analyst from ebikes.ca and set the maximum speed to something reasonable - it will help monitor state of charge so Bad Things won't happen by over-discharging the pack. The readings there will also be somewhat helpful for diagnosing problems (post back to this forum). You can also gets lots of other misc parts here. Great place to buy.

A gear motor will give very good dead start power and lower top speed which sounds appropriate for your needs. The gear motors are more efficient over a broader speed range so her batteries will last longer and her travelling day will be a bit longer while she is just putzing around.

Not sure about the pedal sensor - I think a simple full twist throttle will allow control with large wrist motions. ebikes.ca is moving into some pedal sensors with a new CA V3 coming out soon but it's not quite here yet.

I'm sure there are other good choices that members can make but this should work and give here the all-important zero-start help with some speed regulation to help with slower operator responses once she is rolling.

You could probably do better speed and torque wise with a more complicated rear drive, but your front drive choice seems a good one - it's simpler and will make the project small enough to ensure she is on the road this summer.

 

[dogman dan]

On a trike such as the worksman, a small front wheel gearmotor would be ideal. Small motor, wheel size whatever size the bike is. Something like a bafang, or cute, or small muxus internal planetary geared motor. Don't give her lots of power at first. The ideal thing at first would be a controller with a three speed switch, or a controller with the euro legal speed limiting loop. Then set her up with the slow speed to begin with, not using the switch, but using a hardwired connection that she can't mess with. Or maybe use the three speed switch, but not mounted on the bars, and bury it in tape so it's set to your speed choice. A CA could limit speed, but I can't think of a way to limit her from reprogamming it at will. Hardwiring the speed switch permanently would be harder for her to hack.

The big "adult trikes" in the delta type are very unstable at higher speeds, so limiting her to power to go 10-15 mph permanently is best. Above 15 mph, they simply don't steer at all.

Later on when she's older, I'm assuming she's not a teen yet, she could graduate to a nice tadpole trike.

 

[teklektik]

A CA could limit speed, but I can't think of a way to limit her from reprogamming it at will. Hardwiring the speed switch permanently would be harder for her to hack.

Good point - I guess 'inner street racer' tendencies are where you find them .

 

[JDPA]

Good point - I guess 'inner street racer' tendencies are where you find them .

Yes, this would be the child who likes to ski straight down hill to compensate for her lack of speed walking/running!

Thank you for the commentary thus far, please keep it coming.

 

[MikeFairbanks]

Hey, JDPA: Where are you located?

Oh, and what someone else said: Just get SLA batteries (sealed lead acid). On a tricycle there's no need to go light and, in fact, if the battery is low it will add more stability. Plus SLA is much cheaper and you can pick up replacement batteries in any town.

36 volt, maybe even 24 volt would work well in her situation.


What kind of terrain are you talking about? Just smooth stuff? dirt?

 

[ddk]

instead of building a tricycle you could purchase an EMoto or similar trike already assembled with both a pedelec and a throttle for under $1500 in the states. If you live in the usa check out e-e-e-bay

The EMoto is equipped with a Panasonic lithium 9AH battery with a range of 5-10 miles and the battery is as easy to charge as an SLA battery, only lighter
The pedelc system takes a few minutes to get used too and it is on full-time unless over-ridden by the twist throttle or the e-brake.
It uses a MXUS front-geared hub motor speed-limited to 8 MPH, which is just about right for a standard upright delta tricycle, as they are easy to tip if turned too sharply. The pedal gearing is also set at about 8 mph tops

I own one and I like it
I've had some experience with some other manufactured tricycles and this year they are mostly offering Lithium batteries.However, the Panasonic battery is pretty safe and light weight with a very good connection system, making it very easy to put on/take off the trike

 

[ddk]

...
The big "adult trikes" in the delta type are very unstable at higher speeds, so limiting her to power to go 10-15 mph permanently is best. Above 15 mph, they simply don't steer at all.

...

I regularly go downhill at over 30 MPH and my standard delta trike has no steering problems to speak of.
However it can tip over at 3 MPH if attempting a 90 degree or greater turn.
My semi-recumbent trike beats the turning and downhill speeds of the delta trike because of it's lower center-of-gravity and much better aerodynamics and it's inability to turn 90 degrees.

just sayin'

 

[REdiculous]

I regularly go downhill at over 30 MPH and my standard delta trike has no steering problems to speak of.

At 30mph you're not steering....you're going forward with minor corrections, and you have to make really wide turns or you eat dirt. Sorry.

A friend of mine had a couple trikes that we pedaled around town for a couple years and even at pedal speeds, turns were dangerous. Eventually we learned to ride on 2 wheels around sharp corners. :lol:

At some point we added ropes to the handle bars so we could sit where the rear basket would be...wheelie competitions...fun. Lower CoG too, so turns were a little safer....except there's less weight on the front wheel..

 

[ddk]

I regularly go downhill at over 30 MPH and my standard delta trike has no steering problems to speak of.

At 30mph you're not steering....you're going forward with minor corrections, and you have to make really wide turns or you eat dirt. Sorry.

A friend of mine had a couple trikes that we pedaled around town for a couple years and even at pedal speeds, turns were dangerous. Eventually we learned to ride on 2 wheels around sharp corners. :lol:

At some point we added ropes to the handle bars so we could sit where the rear basket would be...wheelie competitions...fun. Lower CoG too, so turns were a little safer....except there's less weight on the front wheel..

I handle the turns I encounter quite nicely, i.e if the 'suggested' turning speed sign says 25 MPH the trike will safely make the curve at about 25 MPH...
-but you're very right about turning too sharply, as I also pointed out.
The EMoto uses 24" wheels all around. Having 20" wheels in the rear would likely make an upright tricycle a bit safer on turns
Sitting very low is the best- like a Big Wheel (TM) :lol:

 

[teklektik]

instead of building a tricycle you could purchase an EMoto or similar trike already assembled with both a pedelec and a throttle for under $1500 in the states.

This is exactly what is needed - the right motor, etc except that it's based on the adult Schwinn Meridian trike. The target frame that JDPA has selected is a child-sized folding trike (remember: 'very petite daughter').

Looks like the Worksman is sized right and will let them transport this to remote touring spots, etc, for family biking (someone did their homework ).

Okay - so cell_man is one 'known' source for a couple of possible packages - anybody else want to suggest known specific packages/vendors that are reliable? This is sort of low-powered stuff for a change, but we must know some good vendors who can take over more detailed discussions and support... a US outfit, even if slightly more pricey might be good to get on the table as an option.

 

[teklektik]

JDPA-
By the way - here's a company that makes really neat bike flags that your daughter might enjoy. She can design her own
Purple Sky Flags

 

[JDPA]

This is exactly what is needed - the right motor, etc except that it's based on the adult Schwinn Meridian trike. The target frame that JDPA has selected is a child-sized folding trike (remember: 'very petite daughter').

... a US outfit, even if slightly more pricey might be good to get on the table as an option.

From all your helpful feedback, I know a lot more than when I started. Thank you. The "therapeutic" bike option is
Amtryke and seems very similar to the Worksman, but with a lower step over. The inseam listed is longer so I may have to get on the phone with them. My daughter is about 52" and 55lbs with an inseam of about 24". I may be able to get some financial assistance for the Amtryke, giving me more to spend on motorizing. The high handlebars of the Worksman makes me wonder, but it's a minor detail (flashback to my youth of high handle bars and banana seats!)

I do expect I want to stay away from anything with coaster brakes or front drum brakes, but I would welcome clarification on this. I understand selecting a motor sized for a larger wheel (lower RPM) to reduce top speed. That makes sense and will be a point to remember. The choices of 24/36/48V are not clear except to believe it's related to torque and speed. At 55lbs, she's not a lot to move, the motorized bike will weigh more than her. So, low power, low speed is the goal. Our trail riding with this would be limited to roads or rails to trails type surfaces (paved, packed gravel). The co-Pilot is our off road solution when trails are much less consistent and narrower. The ideas to regulate the speed will also be remembered. I like the KISS principle and don't see the need for the CA (from what I understand).

I have visited cell_man's site and will need to learn more. I don't recall an SLA battery option, but I may not have understood all that I was looking at. I do like the idea of one-stop shopping to know that all the parts are compatible as well as advice. My original thought on pedal assist was to require that she make an effort, this is her physical therapy too, but I see the concern with inadvertently activating the motor. I didn't realize they were that sensitive. Is there a way to set sensitivity?

So, while this isn't a build for speed or looks, I do appreciate all of the feedback. I'd still welcome more vendor ideas and things to think about. I'd like a vendor that can work with me (ex. mounting the lower RPM motor on a 20" wheel) and who likes to come up with solutions to a challenge. We're in the Northeast and have been teased with wonderful spring weather. We are looking forward to a nice long biking season (we're fair weather bikers )

Thank you again.
JD

 

[ddk]

instead of building a tricycle you could purchase an EMoto or similar trike already assembled with both a pedelec and a throttle for under $1500 in the states.

This is exactly what is needed - the right motor, etc except that it's based on the adult Schwinn Meridian trike. The target frame that JDPA has selected is a child-sized folding trike (remember: 'very petite daughter').

LOL I missed the "very petit daughter"
sorry
however for edumuncation purposes:
the EMoto is not based on a Schwinn Meridian in any way, except they're both upright delta tricycles.
The comparison ends there.
My inseam is 29" and I have to have the handlebars and seat adjusted to their highest settings
...alas the EMoto doesn't fold but that's why people invented cargo carriers (for scooters and tricycles) with bike rack attachments.
YMMV

Op: Good Luck in your search
BMS Battery also sells pedelec systems with/without torque controllers and might have everything you need - shipping is a bother (expensive), however.

 

[Drunkskunk]

Voltage relates to speed and power. The do make 24 volt systems, but they are mainly useful for flat street riding, 2 wheel bikes, and a light weight rider over short ranges. who wants a little assistance sometimes. Its just not something I'd recommend for a trike, or off road, even with a light rider who needs assistance most or all of the time.


Higher voltage often means more speed, but it also means more power and capabilities. 48 volts is what I would recommend for an adult who needed the assistance. 36 seems about right for a child. If the speed is too high, the CA can limit the speed, but that may not be needed.

SLA, Sealed lead acid is heavy, and inefficent. Due to peukert effect, you'll need almost twice the capacity of battery for SLA as you would for Lithium. a 36V 10Ah Lithium (A123 round cell packs) will weigh 8-10 pounds depending on the source. you would need a 36V 20Ah SLA to get the same range, which would weigh 40-50 pounds. thats a lot of dead weight for a 55 lbs child to handle. the motor will move it forward, but she still has to steer and brake that weight.

And SLA has a very short life, even when taken care of. Good Lithium can be twice the cost, but should survive 4 times as long Minimum.

As for handlebars, those are cheap and easy to replace. Places like http://www.choppersus.com/store/product/469/Handlebar-Cruiser-Round-CP/ sell cruiser bars that are lower and come back farther, and may be easier for her to reach.

 

[MikeFairbanks]

Jason, the owner of ebikekit.com has a great all-included product. All you need to provide is the trike. His kit will handle the rest.

Hey, have you thought of one of these?

http://sites.target.com/site/en/spot/mobile_product_detail.jsp?tcin=10935951&keywords=Tricycle


Some are cheaper, but a trike like that and ebikekit.com's basic kit will run a grand, is super easy to install, and will have her freakig rockin safely. I want to make one too, but faster than safety or sanity allows.

 

[lcyn]

I would suggest the 350w geared kit from E-Bikekit.com. It is a very efficient motor, and would provide all the power needed for your daughter. Plus it is a complete kit, and excellent customer service. You do not want to overpower a lightweight child on ebike. Trailmate makes small recumbants for a reasonable price. The Trailmate Junior is $649.oo, and looks to be good quality.
Where are you located? There may be someone in your area who could be of help.

 

[Mundo]

I was looking for bike trailers a few years ago, when I came across this. Certainly a good choice for some special needs kids.

http://www.caboosetrailerbike.com/

 

[Mundo]

Here's another idea, trike kits.

http://www.choppersus.com/store/category/1/74/Trike-Kits-Parts/

 

[dogman dan]

So your superior trike riding skills makes it okey dokey to hand a child a trike that hauls ass. Riiiiight.

I ride a pedal powered trike at work for the last 4 years daily, so I'm not totally ignorant of the handling properties of a schwinn meridian. My first ebike was a motorized meridian that went 30 mph. At 30, I found it nearly impossible to jink 6 inches over to avoid a pothole or broken glass in time.

So to clarify, it was not unsteerable, so much as unsteerable in time. Have you ever had a car crowd you off the road? Try it on a schwinn trike at above 25 some time. As soon as you get off the flat road and onto a well sloped shoulder at 25 mph, the trike naturally turns downslope. At 15 mph this can be contolled, but at 25 you are going ditch diving. On a two wheel bike, this tendency to head downslope is not a problem.

I don't know if tadpole trikes do this, but deltas do. On a sideslope, they pull hard towards the bottom. Cornering is not as much a problem. You see the corner coming, have time to set up to turn, slow down and oddly lean out in the corner, or get the hang of two wheel turns. It's the sudden unexpected direction change when running at speed that is not easy. On a two wheeler, you just jink over easily and avoid that board full of nails or whatever.

I'm just saying, my experience led me to believe that the best top speed for the schwinn meridian trike is 15-20 mph. Limiting this kid's speed will also allow the parents to keep up without motors or heavy sweating.

 

[JDPA]

I would suggest the 350w geared kit from E-Bikekit.com. It is a very efficient motor, and would provide all the power needed for your daughter. Plus it is a complete kit, and excellent customer service. You do not want to overpower a lightweight child on ebike. Trailmate makes small recumbants for a reasonable price. The Trailmate Junior is $649.oo, and looks to be good quality.
Where are you located? There may be someone in your area who could be of help.

We're in PA. I looked at a recumbent, but was concerned about the low height and visibility (and to some degree, "fitting in"). I hadn't seen the Trailmate Junior Joyrider and like the cargo basket and it's not so super recumbent style. I still think she would need some e-assistance. Could something like that still be modified? If so, how? Also, we have to consider ease of transport. We have a hitch mount Thule rack, as well as roof racks or could likely fit this one assembled in the back (unlike the uncollapsed Worksman which was taller) of the SUV. Thanks.