Help! Yuba e-conversion vs Trek e-conversion

[vess]

Hi all,

I own a very nice Yuba V4, and a just fine Trek Commuter Bike. I like to bike to work; it's roughly 5 miles each way, with some SIGNIFICANT grades between; I have seen many spandexed weekend riders walking up one of the hills on the way home to my house.

I can barely get the Yuba in and out of town, and with a kid on the back it's a major difficulty = I don't do it.

So, my original plan was a stokemonkey, then they were discontinued. Then, my plan was convert my Trek, throw a seat on the back for one kid, and later convert the Yuba.

I commenced researching e-bike conversions, ended up here reviewing circuit board diagrams and freaked out.

All I want is to get in and out of town on my Yuba with up to two kids on back! Is that so wrong? I'm 6'0 and 225 lbs. Speed is not a major requirement, but hill climbing is.

So, here's my question:

1) Is it so cheap to convert the Trek that I might as well do it as a warmup before I do the Yuba? I'd eventually like both done so that my wife and I can take everybody around town between us.
2) Pedelec systems... What's up with these? I tried one and liked it. I WANT to pedal. I hated the StokeMonkey's forced pedaling. I also don't like the idea of just using a thumb twist whenever I go somewhere. I want to pedal, I just want some help. Are these systems significantly more complicated to get working?
3) What sort of budget should I expect for the Yuba? I noticed Yuba sells a kit, but it looks like just a front motor. It's really hard for me to imagine a front wheel pulling what could easily be 400 lbs up some of the hills near my house.
4) How technical are these builds? I must admit, I'm overwhelmed at this point.

Thanks for the advice.

 

[neptronix]

Welcome to the forums.

First off, do you have any experience with electronics at all? or even electric wiring or soldering? do you own a multimeter and know how to use it? because other than the knowledge of what parts to pick, that is the fundamental knowledge you'll need to convert something yourself.

No circuit diagrams are needed, i certainly don't know how to read one and i've built 4 electric bikes so far. A hub motor kit will do the job just fine here. But you will need one with pretty significant power, and regenerative braking would probably help on the way down, lol.

Pedal assist is a simple plug in device for many controllers, and they are often already setup to function with the sensor. The problem is that the operation of the pedal assist is not smooth or proper. And i have in fact had mine jolt me forwards unexpectedly with the slightest nudge of the crank on more than a few eBikes i had tested prior to building my own. Really, the throttle is not so bad. It can blend in with the pedal power very nicely.

The main things you need to worry about is the specs of the parts. On a hill where lycra-clad riders are huffing and panting, you're going to be running the electric bits at or near their maximum ratings.

So the question is.. how far, and how fast do you want to go? also, how long is this hill and do you know what the grade is?

 

[dnmun]

if you wanna do a stoke monkey, go read rassie's thread on his stoke monkey setup on his trike. you should be able to fit it in the frame of the yuba.

 

[dogman dan]

I could be misinformed, but I believe the yuba conversion kit is a hubmotor that drive the chain. But I believe it does have a freewheel incorporated so you don't have the stokemonkey style forced pedaling.

If your hills are that steep, yeah, you are asking a lot to haul you, a motor, a battery, a bike, groceries, and two kids up the hill.

But a good through the chain system on a yuba will do it if anything can. On the hub, motors get murdered by crawling too slow up hills.

So the question remains, how steep? Find out using map my ride, just mapping about 1/2 mile at a time to get the most accuracy of the grade.

If the hills are mostly below 5% you should be ok even with a hubmotor. If closer to 10% then you'll really need the through the chain drive, and use the lowest gears. It's an expensive kit though, for the custom parts and small production run.

 

[Jethro56]

Neptronix gives pretty good advice. I live in the flats so my first build wasn't too demanding. I'm a retired Industrial Automation guy so the electrical part was straightforward for me. I haven't paid much attention to the guys building their own controllers as it seems too much like work and my application doesn't require anything custom. For my first build a year ago I decided a hardtail MTB bike was a good first project. The durability and availability of them make them a good choice.

I'm 6'2" and 230 lbs so a ones sizes fit's all bike from Walley World was too small and Craig's List used bikes too rare. I bought a large Giant Sedona and if I had to do it again I'd get an Extra large. At 6'0" you have a much better chance of finding one. I assume your Trek commuter has 700c wheels and 28mm tires. Not a good choice for heavy loads in hilly locales. You need smaller diameter wheels capable of wide tires. The Yuba is a much better choice but a rather expensive bike for a first build.

I got my Sedona up and running last year and put 1000 miles on it. It's fairly fast @28 mph but the front was too light for windy conditions and it didn't have excess weight handing ability for cargo. The Xtracycle longtail conversion should solve these issues and that's what I'm working on now. I could ride it in a hour or so but the weather isn't conducive to that yet. So I'm taking my time and working on wire management to create a more stealthy build.

I'd forget the pedelec systems. I bought a controller with "cruise control" on it. The way I use it is I take the bike up to a certain speed say 20 mph and hold the thumb trottle there for 10 seconds I then can release the throttle and the bike will lock on that speed. The power I use is now determined by how hard I pedal.The faster I go the less assist I get from the motor. It's a very smooth transition. With the gearing I have 22mph is a good speed for the bike. If I don't want to pedal I set the speed from the motor at that. If I want to pedal a lot I set the speed to 18 and pedal harder to get up to 22. My rear brake lever has a switch in it that releases the bike from cruise control or you can blip the throttle as well.

I don't know if you want this to be a hobby as I do or just wanting to solve a problem. I like the idea of using an inexpensive bike as a prototype. Use it for a year and then refine it. But I'm a bike geek and http://www.xtranormal.com/watch/6272413/n-1-boomer-version kinda describes me.

 

[dogman dan]

If his hills are that steep, a regular hubmotor conversion won't work so well. He'll need something other than a regular winding in 27" rim. A farily short steep hill can be charged at 25 mph, and you'll get up it ok though.

More than a mile of 10% is pretty challenging though, when cargo or kids is carried up it.

 

[itselectric]

Hi all,

I own a very nice Yuba V4, and a just fine Trek Commuter Bike. I like to bike to work; it's roughly 5 miles each way, with some SIGNIFICANT grades between; I have seen many spandexed weekend riders walking up one of the hills on the way home to my house.

I can barely get the Yuba in and out of town, and with a kid on the back it's a major difficulty = I don't do it.

So, my original plan was a stokemonkey, then they were discontinued. Then, my plan was convert my Trek, throw a seat on the back for one kid, and later convert the Yuba.

I commenced researching e-bike conversions, ended up here reviewing circuit board diagrams and freaked out.

All I want is to get in and out of town on my Yuba with up to two kids on back! Is that so wrong? I'm 6'0 and 225 lbs. Speed is not a major requirement, but hill climbing is.

So, here's my question:

1) Is it so cheap to convert the Trek that I might as well do it as a warmup before I do the Yuba? I'd eventually like both done so that my wife and I can take everybody around town between us.
2) Pedelec systems... What's up with these? I tried one and liked it. I WANT to pedal. I hated the StokeMonkey's forced pedaling. I also don't like the idea of just using a thumb twist whenever I go somewhere. I want to pedal, I just want some help. Are these systems significantly more complicated to get working?
3) What sort of budget should I expect for the Yuba? I noticed Yuba sells a kit, but it looks like just a front motor. It's really hard for me to imagine a front wheel pulling what could easily be 400 lbs up some of the hills near my house.
4) How technical are these builds? I must admit, I'm overwhelmed at this point.

Thanks for the advice.

vess:

there are three ways to convert Yuba cargo bike:
1.) Yuba USA is now selling eMundo, contact them and see what the can offer you:
http://yubaride.com/electric-cargo-bicycle

2.) Urban Commuter sell a mid drive system, very similar to stokemonkey, except this is custom build for Yuba, work excellent, check the store and youtube link below
http://urbancommuterstore.com/
http://www.youtube.com/watch?v=R5ZdbAGKJ90

3.) The Yuba rear drop are differ from standard bike, in order to use rear motor, you need to have custom make Yuba torque plate, once you have the torque plate, you can install any rear motor conversion, in this example, Kiwi, one of our member had made it available to anyone, check out the link, and Kiwi build thread
http://endless-sphere.com/forums/viewtopic.php?f=31&t=31881&p=464241&hilit=kiwi+yuba+torque+plate#p464241
http://endless-sphere.com/forums/viewtopic.php?f=6&t=14375

I personally use xtracycle with electric assist, in comparison to Yuba, xtracycle are much lighter weight, most of my cargo in around 200lbs, I am fine with it. But if I need to carry 350lbs+ cargo, then a Yuba is the workhorse for it.

In regarding the 3 option that I suggested
option1 is basically a eZee front wheel kit, there are a few vendors that sell them. But I think eMundo may have proper mounting for the Yuba, you should find more information directly from yubaride.com

Front wheel drive on cargo bike is not a bad idea, when you put 400lbs weight at the back, and going up the hill, you could start lifting you r front wheel, which make it unbalance. By have the front wheel, it put the weight down at the front.

option2, is an improved design from stokemonkey, but design for Yuba. A mid drive system will give you more low speed torque, for climbing hill, it is a wonderful setup but a bit more noise.

option3, it open a lot more option for you, with the kiwi torque plate, you can use almost any rear motor kit for the job. But most people will have choose the biggest motor as possible for carry heavy load.

I hope this help you out.

Ken

 

[Drunkskunk]

1) Is it so cheap to convert the Trek that I might as well do it as a warmup before I do the Yuba? I'd eventually like both done so that my wife and I can take everybody around town between us.
2) Pedelec systems... What's up with these? I tried one and liked it. I WANT to pedal. I hated the StokeMonkey's forced pedaling. I also don't like the idea of just using a thumb twist whenever I go somewhere. I want to pedal, I just want some help. Are these systems significantly more complicated to get working?
3) What sort of budget should I expect for the Yuba? I noticed Yuba sells a kit, but it looks like just a front motor. It's really hard for me to imagine a front wheel pulling what could easily be 400 lbs up some of the hills near my house.
4) How technical are these builds? I must admit, I'm overwhelmed at this point.

Thanks for the advice.

Welcome to the forum.

1. Thats a very good idea, as the yuba will present some unique chalanges. Experiance pays for it's self. what you learn on the Trek will save time, money, and headaches later on the Yuba.

2. There are very few good pedelec systems out there. But with almost any electric motor you can pedal and use the motor together without being forced to pedal. The stokemonkey was the acception, but a simple freewheel crank would have cured that. Basicly you only need a throttle, and with it you can dial in the exact amount of assist you want on an instant bassis.

3. Yuba won't be cheap to do it right. Probably in the 2k range. But I'm thinking you'll need a stokemonkey clone built from a few custom parts (with a freewheel crank) to get the gearing you'll need to haul 400lbs up a hill people have to walk normal bikes up.

4. About like IKEA bookshelves: harder than they look like they should be, but easy enough almost anyone can do it. Atleast for the Trek. The Yuba will be more of a chalange since nothing will meet your goals for it off the shelf, and you'll need some custom parts and fitting to make it work.

 

[tomk2]

I converted a TREK after months of reading and thinking I understood the tradeoffs concerning an e bike build.

As usual when building something I had little experience with - I didn't know what "I didn't know".

I strongly recommend you keep things simple at first and build a prototype (TREK).

Keep reading posts by Dogman and other knowledgeable people here - they know a lot.

For E bikes (and all E vehicles) long steep grades are a killer especially when you weigh over 200 lbs. An engineer I work with bought a Nissan Leaf and is chagrinned to find out how hills and high speeds severely reduce its range. It made him realize how much energy is available in a gallon of gas.

 

[vess]

OK,

This is super helpful, thanks all.

The worst of the hills include some 14 and 15% grades, averages out to 10% maybe. That hill is a mile. There's also a solid 6%-er that's a half mile.

I don't wish to solder. Well, I don't mind a little soldering. I don't wish to be solely responsible for designing my battery and charger layout.

I don't need to go fast, 20 mph is fine with me.

I think all this adds up to that urbancommuterstore.com kit, or a cheap-ish first-try Trek kit, but with a near-term eye to the Yuba.

Does anyone have experience with urbancommuterstore m-drive kit? I can search the forums for thought as well.

 

[ryan]

I'm currently building a monster Yuba, and confirm the advice given here. Kiwi was one of my role models along the way.

But for your specific needs I'd seriously consider urbancommuter's mid-drive setup. It is affordable, powerful, and really well integrated into the Yuba frame. One of my main goals was stealth, so mid-drive ended up outside that goal, but for your purposes it should be right on target.

Also, I'm a software guy with no EE experience, but the guys here are great at walking you through what you'll need to know. And with a kit like UC's mid-drive, you should be well on your way.

I look forward to seeing your build thread. Take lots of pictures!

 

[ryan]

You should also check out the Yuba Builds thread, I you haven't already.

 

[dogman dan]

Very few stock hubmotor kits are going to be up to that hill, + cargo. A mile of 15% is capable of smoking a motor that is stalling too much. You've gotta go through the chain, so you can gear down and spin the motor fast while crawling up the hill.

Or build a flyweight motorcycle capable of going hill? Was there a hill? I didn't notice it going 50 mph. Not exacty the way to go with kids aboard.

If you want to go for a test build on the trek, go to the for sale section of this forum, Look for Methods, and look at the wife kit. At 48v, 20 amps, it can climb a mile of 15%, But it won't like it with cargo much. It will do just you though.

That is, if you are in North America. Might get pricy if you are in Europe, to ship from the USA.

The other motor known to climb well is Cellmans Mac 12 turn. See that at the Emissions Free website.

With either motor, you might need to relace to 700c too, mo money.

Either of those would climb 15% on the trek. If it was less than 10%, then a front hub on the mundo would work reasonably well. At 15% you will start spinning the wheel a bit. Go for the mid motor chain drive approach on the mundo for sure.

 

[pdf]

I have a Stokemonkey. I think I chimed in the first go round.

Anyway, with that much weight (kids, groc.), you will have to have a mid drive and a well made one at that. Even going up a 15% grade with a mid-drive is going to require the same amount of power and that power and torque is going to go through your drive system. I have worn out one rear sprocket, a chain, and a bottom bracket with my Stokemonkey. You'll need good parts.

The Yuba will do what you want I'll wager but you will need to be able to supply the power and torque you need for climbing a hill with a heavy load so you will need good drive parts, and a good battery and controller.

 

[neptronix]

14%-15% grades? damn. You will end up designing something like my pike's peak hill climb setup - slow winding motor, small wheel, high volts.

But that bike can't handle a very small wheel..

I would vote for the urban commuter mid drive setup, if you have the money to afford it. It would be the best of all worlds - nice integration with pedaling, much higher efficiency on the steep parts, and little to no risk of overheating.

The MAC motor kit from cell_man in an appropriately sized wheel will work, but you'd be pushing the motor very hard on a 14%-15% grade. If you want a monster hill climber motor hub motor though, the MAC or BMC in a slower speed winding ( aka "10T" ) is one of the best options i can think of. I am 230lbs and like to carry tons of battery and see some very major hills - it's done the job for me quite well. ( see my build thread in my signature )

http://emissions-free.com/catalog/i22.html


Avoiding designing a charger and battery setup is easy.. you have lots of room for battery on that bike anyway. Go with a large amp hour ping battery, as in 20AH or more.

 

[Drunkskunk]

OK,

....
I think all this adds up to that urbancommuterstore.com kit, or a cheap-ish first-try Trek kit, but with a near-term eye to the Yuba.

Does anyone have experience with urbancommuterstore m-drive kit? I can search the forums for thought as well.

That kit is Very overpriced, and it's missing a couple of important parts. But ultimatly, its what the Yuba needs.

The critical missing part is the freewheel crank, so the motor can turn with out you needing to pedal.


Its a $1000 kit with a $250 motor and another $100 in parts. http://www.emissions-free.com/catalog/i1.html The gears and jackshaft used in that kit are similar to what you'll get in a gocart jackshaft kit, $29 from Northern Tool. I just bought one.

But if you don't have access or skills to fabricate the frame to hold the motor, it isn't the worst deal in the world.

 

[dogman dan]

One other method I wasn't thinking of this morning hasn't been mentioned yet.

Two hubmotors. In particular, two slower windings such as the wife kit, or the 12t mac. Or even one of each.

By doubling the wattage, you now have the power to keep speeds up climbing that hill, then the motors don't fry from being stalled. You'd have lots of power, yet if you used the slow windings you'd not be having crazy fast speeds.

The only issues would be affording enough battery to provide double the power, and whatever the problem is with fitting a rear hubmotor.

Anybody want to describe that problem? Is it wider or narrower than normal dropouts or what?

Anyway, double motoring the yuba would allow experimentation on a cheaper bike, in the same wheel size. So you could start with a bike that does the ride with just you, then add the second motor to the yuba later.

 

[inkeeper77]

What did you choose? Keep us updated!

In response to the above post, the M-drive kit is NOT missing a freewheel crank- it is freewheeled, so you can use the motor without turning the pedals. It is just done differently than the stoke monkey is. I just ordered mine, and the creator has improved the design, and it looks a lot lighter. I will be posting a build thread once I receive it, and get everything else needed. If you are still choosing, I will cerainly report on the m-drive performance on at least 40v, but I have an idea on how to at least test higher voltages.

You may also be interested in a 2wd mundo thread on the forums. I am not connected in any way, but I am certainly going to use a lot of its ideas!
http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=36959&hilit=yuba+mundo

 

[mabman]

OK,



The critical missing part is the freewheel crank, so the motor can turn with out you needing to pedal.

The way I understand the UC mid-drive system is that there is a freewheel on the jackshaft so that you don't need a freewheeling crank, that is why it can also run a 3 ring crank with the aid of a tensioner between it and the jackshaft sprocket. To my knowledge there is no such thing as a 3 ring freewheeling crankset.

I agree that the system is a bit spendy but I always thought the Stoke Monkey, which was as much if not more was spendy, especially due to the fact that it was not freewheeling which I know some people don't mind but doesn't work for me. The UC is probably trying to make a buck so that he can pay the rent and there is nothing wrong with that. If you have the skills to build something on your own that is another story.

 

[spinningmagnets]

Rassy used a 9C to add a mid-drive to his trike, some good ideas and solutions to common issues there. Might be doable for a Yuba/Trek...

"6X10 Mid Drive Trike"
http://endless-sphere.com/forums/viewtopic.php?f=28&t=18606