First Enduro Build For My Boys (14 & 12)

[thebruce]

Hi there - first post here. My boys (14 and 12) are stanning on Super 73s, Surons and Talarias. I told them I would only consider the expense if they learn how to spec, build and maintain one themselves. We've built computers before and I have an old boat and 911 they help me work on so felt this would be a good boys bonding experience. I had some questions (and would love any feedback) from the pros here before we jump in. Sorry for all the questions in advance

Our inspiration was this build from ROOK. He did some epic work. RooK on Instagram: "#zeromotorcycles #stealthbomberebike #enduroebike #customebike"

1. First, we are looking at the Enduro frame with 20x4 moto wheels. This seemed like the lightest frame and would be something they can continue to customize.

- Is that what most of the cool kids are doing these days or is there something newer out there?
- if installing 20x4 fat tires we would need a 170mm frame and 170 hub right?

2. For the motor and controlled I wanted something that wasnt too fast for them at this age but they could upgrade when they get older. Im talking to NBPower (which ive read some good things about from other people's builds) and I was debating two kits:

- option 1 a 2kw hub kit: this was my original plan as lower cost and slower speed (and cheaper at ~ $440). But NBPower said for a 2kw motor you could use a cheaper downtube battery (~$400) - but that wouldn't fit in the enduro frame...

- option 2 a 3kw hub kit: so they recommended a 3kw motor for ~$610 and 72v 20ah battery for $680. comes with a Sabovoton controller. they said the 150mm dropout motor is a QS but the 170mm is their own "NB" brand and the battery is Chinese 2170 cells.

My questions are what do you guys think is the optimal motor + controller + battery size for younger kids that hopefully could be upgraded as they get older. Would you always have to replace the battery and controller if you are upgrading to a larger motor in the future...?

3. I have researched other peoples builds and think I have most all the major components: frame, motor kit, battery, suspension, etc. But I dont know what I dont know and there are some areas im not super clear on:

- what additional hardware would be needed for the front fork assembly (that would not be included with the fork kit): bearings, etc?
- for the drivetrain do most people just use a single gear (seems simpler) or install gears, de-railers, etc. any recommendations there.
- besides the motor and controller kit, what other parts are typically needed for the electronics?
- any recommendations on mounting the controller and battery in the enduro frame. ive not found any info yet on best methods to secure the battery and controller.


Sorry for the detailed questions. I hope to post project updates as we progress.

 

[amberwolf]

Which battery you use depends on what controller you use, and which controller you use depends on what the motor has to be supplied with to do the job you require the system to do for you (as the motor size/characteristics also depend on that).

I would recommend sitting down with them and defining what specifically you want the bikes to be able to do, under what riding conditions, and how long you want a ride to be able to last under the worst case conditions.

Then you can take that to the ebikes.ca motor and trip simulators, and find out what power requirements you'll have for worst case conditions (which tells you how big the motor and controller have to be), and what wh/mile capacity usage that will have (which tells you how big the battery has to be).


Regarding suspension--you'll get better suspension performance with a middrive rather than a heavy hubmotor in the wheel.

You can also regear a middrive to get better torque or better speed if you find something was wrong with original calculations and it doesn't do what you want after its' built (or if you change your mind about what you want it to do).

A hubmotor is simpler (assuming you build good axle clamps to prevent *any* movement or rotation of the axle; the hardware that comes with motors is hardly ever good enough, and what comes on frames is often a joke), less maintenance, etc., but it often makes wheel builds more complicated or more compromised and sometimes less reliable under harsh conditions than a "normal" wheel would be.

 

[amberwolf]

1. First, we are looking at the Enduro frame with 20x4 moto wheels. This seemed like the lightest frame and would be something they can continue to customize.

Which specific frame? There are probably *at least* hundreds of "enduro" frames and clones of those and clones of those and so on. Each one will have different materials and strength and weight and quality, and different dimensions, geometry, etc.

Based on the Rook link, you're probably thinking of an EEB or Electric Enduro Bike (or variations thereof),

electric Enduro frame - Google Search

but Enduro frames also include plain bicycles, like these

Enduro frame - Google Search

Would you always have to replace the battery and controller if you are upgrading to a larger motor in the future...?

That depends on what you get originally. If you get a programmable controller that is capable of as much as you would ever want to do with the bike, probably complete overkill for the initial build, then it would probably continue to work for whatever future upgrades you do. So you'd get one with higher voltage and higher current than you would presently use, and then set it up to run lower power to match your initial usage and parts.

The battery is the heart of the system, so it must supply all of hte power, current, voltage, that runs the entire system. So it also has to be much better than what you need at first if it is to be kept when you upgrade to that level.

Remember also that the more power you use, the shorter range you get with the same capacity battery (Wh), so you would also want a batter with much more capacity than you need so you will still have the required range even at higher power usages.

(that simulator will let you work out an initial power level, then potential future upgrade levels, and their matching Wh/mile capacity usage)

- what additional hardware would be needed for the front fork assembly (that would not be included with the fork kit): bearings, etc?

That would depend on the specific fork kit, and the specific frame.
"Fork kit" comes up with many many possible results

fork kit - Google Search

- for the drivetrain do most people just use a single gear (seems simpler) or install gears, de-railers, etc. any recommendations there.

If you have a hubmotor, there is no drivetrain; it's all inside the wheel.

If you aren't building a motorcycle and instead are building a powerful bicycle or moped, with working pedals, then what you need depends on exactly what you want to be able to do with it under what conditions, and whether it will ever be used under pedal power (without the motor), and under what conditions.

- besides the motor and controller kit, what other parts are typically needed for the electronics?

Depends on what specifically you want the system to do for you, and what comes in the "kit".

- any recommendations on mounting the controller and battery in the enduro frame. ive not found any info yet on best methods to secure the battery and controller.

That will depend on your specific frame, battery, and controller, as well as the conditions they all must survive.

 

[thebruce]

@

Which specific frame? There are probably *at least* hundreds of "enduro" frames and clones of those and clones of those and so on. Each one will have different materials and strength and weight and quality, and different dimensions, geometry, etc.

Based on the Rook link, you're probably thinking of an EEB or Electric Enduro Bike (or variations thereof),

electric Enduro frame - Google Search

but Enduro frames also include plain bicycles, like these

Enduro frame - Google Search

That depends on what you get originally. If you get a programmable controller that is capable of as much as you would ever want to do with the bike, probably complete overkill for the initial build, then it would probably continue to work for whatever future upgrades you do. So you'd get one with higher voltage and higher current than you would presently use, and then set it up to run lower power to match your initial usage and parts.

The battery is the heart of the system, so it must supply all of hte power, current, voltage, that runs the entire system. So it also has to be much better than what you need at first if it is to be kept when you upgrade to that level.

Remember also that the more power you use, the shorter range you get with the same capacity battery (Wh), so you would also want a batter with much more capacity than you need so you will still have the required range even at higher power usages.

(that simulator will let you work out an initial power level, then potential future upgrade levels, and their matching Wh/mile capacity usage)



That would depend on the specific fork kit, and the specific frame.
"Fork kit" comes up with many many possible results

fork kit - Google Search

If you have a hubmotor, there is no drivetrain; it's all inside the wheel.

If you aren't building a motorcycle and instead are building a powerful bicycle or moped, with working pedals, then what you need depends on exactly what you want to be able to do with it under what conditions, and whether it will ever be used under pedal power (without the motor), and under what conditions.


Depends on what specifically you want the system to do for you, and what comes in the "kit".




That will depend on your specific frame, battery, and controller, as well as the conditions they all must survive.

@amberwolf - you are epic. thanks so much for the detailed responses. Yes it's an EEB build. I will post progress of the build along the way. thanks again!

 

[amberwolf]

Yes it's an EEB build.

With which specific frame?

(And which other specific parts? And other system / usage details, as brought up above? Telling us these things will help us help you answer your questions...keeping all the details to yourself doesn't help us help you. )

 

[thebruce]

@amberwolf this is what ive got so far!

Battery	72V, 20Ah, 2170 cells
Motor Kit	NBPower: Qs205 v2 3kw 3.5T, 150mm dropout + 80A Sabvoton + UKC1
Enduro Frame	Frameset Electric Enduro Black 1.Specifications: Quick detail for Full Suspension Steel 350w-5000w Electric Enduro Bike Frame• Material : steel frame and plastic cover which is using high quality strong 4mm ABS+PMMA anti-scratch plastic. • Warranty : 2 years• Rear shock : 190-240mm are suitable• Seat post (31.6mm) , seat... www.enduroebike.com
Fork	20" Himalo Fat Four 150mm
Rear Shock	FastAce 190mm
Tires	Pirelli Angels 10/80 x16
Charger	5A
Seat	Garmata MX2 Motocross Saddle
Crankset + Chain Ring	Bucklos IXL 104mm 42T
Brake Rotor	Bucklos 203mm
Handlebar	720mm, 60mm Riser
Stem	KRSEC 45mm Short
Brakes	Garmata
Rims	NBPower 20x4

 

[thebruce]

and @amberwolf is it possible to setup a speed limiter in a 80a sabovoton controller in such a way that curious teenagers cant easily access I would like to de-tune the motor to go max 28mph unless im with them.

 

[2old]

I didn't read anything but your post, but you should know that what you are considering is not a bike by CA rules and would require license and insurance. However, there is basically no policing at this time in CA, so you'd be fine (probably) unless they get into an accident. IMO, a better option is a steel bicycle with a DIY kit from ebikesca.

 

[amberwolf]

and @amberwolf is it possible to setup a speed limiter in a 80a sabovoton controller in such a way that curious teenagers cant easily access I would like to de-tune the motor to go max 28mph unless im with them.

You'd have to see if the model-specific controller manual specifies a way to set a speed limit. It may call it out as motor RPM rather than road speed. If it doesn't, you can install devices like the Cycle Analyst from Home page that can be used to limit the system in many ways, and can be "locked" so settings cannot be edited without hooking it up to a computer to do so (rather than from it's own display like usual).

You could set it up so there is an "unlimited" (or differently-limited) preset available via the aux input, and set that up so it requires a physical key you personally keep to unlock it. (can be a real keyswitch lock, or an RFID lock, simple magnet and reed switch or hall sensor, etc. )

If you have sufficient DIY interest / ability you could use an Arduino Nano, PIC, etc., to read a speed sensor and modify an incoming throttle signal to lower it until speed drops below the limit. Requires one A/D input, one digital input, and one D/A output. If you wanted to hard limit it you could have it engage ebrakes until speed is below the limit, but this could be dangerous if not properly designed depending on how the controller does it's braking and how strong it is, vs the riding conditions at any moment.

The same kind of lock can be setup on this, using a second digital input that tells the program to bypass it's limits or to change to a secondary set of limits.

 

[Eastwood]

and @amberwolf is it possible to setup a speed limiter in a 80a sabovoton controller in such a way that curious teenagers cant easily access I would like to de-tune the motor to go max 28mph unless im with them.

You should be able to set the speed limit on the 80 amp Sabovoton
The only way your kids would be able to adjust the speed limit is if they downloaded the MQCON app

 

[thebruce]

You'd have to see if the model-specific controller manual specifies a way to set a speed limit. It may call it out as motor RPM rather than road speed. If it doesn't, you can install devices like the Cycle Analyst from Home page that can be used to limit the system in many ways, and can be "locked" so settings cannot be edited without hooking it up to a computer to do so (rather than from it's own display like usual).

You could set it up so there is an "unlimited" (or differently-limited) preset available via the aux input, and set that up so it requires a physical key you personally keep to unlock it. (can be a real keyswitch lock, or an RFID lock, simple magnet and reed switch or hall sensor, etc. )

If you have sufficient DIY interest / ability you could use an Arduino Nano, PIC, etc., to read a speed sensor and modify an incoming throttle signal to lower it until speed drops below the limit. Requires one A/D input, one digital input, and one D/A output. If you wanted to hard limit it you could have it engage ebrakes until speed is below the limit, but this could be dangerous if not properly designed depending on how the controller does it's braking and how strong it is, vs the riding conditions at any moment.

The same kind of lock can be setup on this, using a second digital input that tells the program to bypass it's limits or to change to a secondary set of limits.

god mode could be fun

I was just reading that the UKC1 has a passcode lock where you can set the speed limit and acceleration params.

 

[thebruce]

I didn't read anything but your post, but you should know that what you are considering is not a bike by CA rules and would require license and insurance. However, there is basically no policing at this time in CA, so you'd be fine (probably) unless they get into an accident. IMO, a better option is a steel bicycle with a DIY kit from ebikesca.

yea thats why I want to lock the bike down unless im with them. they can tell any police officer truthfully their dad locked the bike down to legal CA limits and they have no ability to unlock it. im hoping that will change the conversation from "you irresponsible parents" to "thats a cool project you guys built with your dad and im glad you're being responsible and following the regulations"...

 

[thebruce]

coming together!

you guys have any recommendations on a charger for a 72v 20ah battery?

also does the Sabvoton have a connector for brake lights and headlight, or do you have to wire them?

thx for all the help.

 

[amberwolf]

you guys have any recommendations on a charger for a 72v 20ah battery?

What charge current (amps, A) does the battery support? If you're not sure, pick a 2A charger, it will take half a day to fill it up but it is nearly certain to not damage it.

also does the Sabvoton have a connector for brake lights and headlight, or do you have to wire them?

The motor controllers just control the motor. Lighting is a whole separate system just like on a motorcycle, etc.

You may be able to find lighting that will run directl.,y offf your 72v battery (i.e. will take up to 100v input) but it's easier / safer to use typical "12v" DOT lighting for motorcycles, trailers, etc., and use motorcycle handlebar controls, such as brake levers that have brake light switches in them, etc. Then use a 60-100V range input DC-DC to convert down to 13.6-14.4v (automotive "12v") at whatever current your lights will take to run them.


if you need the levers to also control regen braking you may need some additonal parts like relays, etc, depends on exactly what the controller's regen braking input and control scheme is.

 

[thebruce]

coming together. thx for all the help @amberwolf

 

[nicobie]

That thing is badass! I like the way it looks

I hope your kids appreciate your work

 

[Eastwood]

The bike is looking good! Where did you buy that rear fender?

 

[nicobie]

Need some pics of your kids riding it.

 

[thebruce]

thx all! should have first ride today.

the rear fender is a mucky nutz tire hugger.

some shots of last night putting in the battery and first hall test.

we did have an issue with the charger fuse popping when we first plugged it in. blew the second fuse too and one of the three prongs is charged so sending that one back. not sure what the issue was.

 

[thebruce]

@nicobie its been a great project with them . we've had so much fun working on something different every night and them excited for whatever new part comes.

 

[nicobie]

That pic of your boy is better than one of him riding the bike.

 

[thebruce]

the past couple weeks build.

 

[Slowchris11]

Great project! We are not allowed to do such stuff in Germany. Your son's can be happy to have such a caring dad. Most parents buy them a computer and Iphone to keep them silent.
I technically restored a 1998 VW Rabbit III with my 17 year old daughter, keeping the outside near stock and cheap looking.
Anything from engine to drive train, suspension and back.
She covered 40.000km in two years, it never broke down. We have a good regulation here, she got her license at her 17th birthday and had to drive with an adult on her side till 18.

Children that learn how to use a powered vehicle at young age are better and more responsible drivers for the rest of their life. Just keeping them safe is a challenge and needs strong nerves...
I learned to drive at age 10 (on a vacation in Canada).

Install a cheap 15$ tracker hidden in the battery, in each bike. It will run the next 25 years on the battery, so hardly any load.
This way you always know where your kids are and save you (your wife!) a lot of sorrow and hopefully unnessecary anger when they are missing.
Second, do not wait until the first bike disapears. Other kids will be extremely jealous and not all of them play fair. Locking doesn't help and your kids don't get hurt defending their bikes.

 

[thebruce]

thanks for the tip on the tracker. got one coming in tmrw!

 

[thebruce]

and thats a wrap. bike complete! very happy boys.

now I need to figure out how to tune the sabvoton SVMC7280 controller. I had a cut outs already. and more importantly, the speed limiter on the UKC1 display doesnt work. I need to figure out how to add a speed limit on the controller. I know there is a way to limit the %, but dont understand how that works.