zygotE-Mini/Pit Bike

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

zygotE-Mini/Pit Bike

Post by standfast » Jan 04 2019 7:35pm

Well, back at it again building a few bikes. I finished my first e-bike in 2015. See it here. viewtopic.php?t=60191 It is still up and running. My original li-po battery is getting a bit sacked out with about 2600miles on it. Other than that, it has been very reliable and never let me down. Now I need to build some more bikes so the rest of the family (wife and 2 boys) can join in. My oldest who is 9 has been beaten his POS Mototec cheapy electric bike into the ground. I have fixed it like 20 times now from him jumping it. He has gotten to the point where he just leaves it WOT all the time. Time for something better. I would just buy an Oset, Kuberg, or whatever but they don't have the kind of range to do the trail/exploration riding that my bike does and the areas that we will ride require. I am looking for a bike that can go at least 30-40 trail miles or more. I think I can do it.

For this bike, I am designing it to use mostly pit bike components to keep the cost down and the the durability up. This allows me to use everything from cheaper China pit bike parts or any high end aftermarket parts for CRF50's, CRF70's, etc. if I need to get fancy with one. I need it to be a robust bike that can be dropped frequently etc and be bullied by adults because I am sure that will happen. :) I am building these bikes to be capable of growing with the kids as well. There are plenty of different fork lengths and wheel tire combos that are very affordable that can be swapped on.

I am designing as I build and receive parts. I hope to have the first one up and running to test in about a month or 2. This first bike will have a 12"/12" wheel/tire combo. It's big enough for me to ride it. For my younger son, I am going to use 10"/10" wheels with a much shorter stock crf50 sized fork. For my wife's bike, I am going to use a 14"/12" setup with a longer fork.

The first bike is going to use a smaller GNG motor seen here. https://www.gngebike.com/belt-chain-motor It is a 1500w motor that will be able to take about 3kw peak. This should be good for the 2 kids. This will also fit a longer version motor that has the same mounting which is what I want to use on my wife's bike. Probably the LMX motor or almost any of the motors from Senli magnet.

The controller will be a Kelly mini brushless. For the battery packs on the bikes, I am going to likely try a couple different things. For the small 10" bike, I am going to try running 2 56v (52V nom) EGO 7.5ah tool batteries in parallel for a total of 840wh. These are available at Home Depot which makes it simple. Plus I already have one for my lawn mower. This will not give the ultimate 30-40mile range I want but it will be good for testing and for my youngest boy to learn on. The upside is they have a factory charger and can be charged in an hour. I bet it will get about 15-20 trail miles or so depending on peak current setting. The other bikes will likely get 18650 packs. It will fit any pre-made packs sold by Luna Cycles that are single row. Like this one. https://lunacycle.com/triangle-52v-pana ... ong-range/ or this one https://lunacycle.com/triangle-48v-pana ... ong-range/. There are a bunch of others out there but I need to find out which are using legit cells etc. These packs will easily fit. I may also build a pack for them that utilizes all the space which will fit over 300 18650 cells if I want. I may also try a high discharge pack using 20 4s hard case packs for a 72v 20ah setup that can do 7-8kw. :twisted: That should compete with almost any mini ICE bike out there. I really like this design as it allows easy access to the packs without really worrying about building a battery box to protect whatever I put in there. It's all built into the frame and sealed up water tight with a gasket on the seat clam shell.

I still have some more work to do designing and building the swing arms and more research on parts. Here is some pics of where I am at for now. I will try to update this as I go along.

Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Last edited by standfast on May 06 2020 5:06pm, edited 1 time in total.

Smoke   100 W

100 W
Posts: 213
Joined: Nov 15 2018 11:04pm

Re: E-Mini Pit Bike

Post by Smoke » Jan 04 2019 9:15pm

Very cool. I bought a Burromax TT350R for my young niece's Christmas gift but that is way cooler.
Don't let me out.

User avatar
Chambers   10 W

10 W
Posts: 90
Joined: Nov 11 2011 8:01pm
Location: Brisbane

Re: E-Mini Pit Bike

Post by Chambers » Jan 05 2019 2:28am

Love it. Based on your last build I'm sure they will turn out awesome! Subscribed

User avatar
shortcircuit911   1 kW

1 kW
Posts: 346
Joined: Feb 19 2010 1:24pm
Location: Antioch, CA

Re: E-Mini Pit Bike

Post by shortcircuit911 » Jan 05 2019 1:15pm

Nice build man, clean welds also. This beats my razor MX4000. Love that the kids are involved too, good luck. Sub'd!

Grantmac   10 kW

10 kW
Posts: 680
Joined: Oct 22 2018 12:43pm
Location: Victoria, BC

Re: E-Mini Pit Bike

Post by Grantmac » Jan 05 2019 1:30pm

I'm guessing you have a fabrication business or similar! What does the complete chassis weigh?

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Jan 11 2019 5:33pm

Grantmac wrote:
Jan 05 2019 1:30pm
I'm guessing you have a fabrication business or similar! What does the complete chassis weigh?
The frame weighs just under 15lbs. I hope to have the swingarm parts done this weekend so I can see it mostly together.

Good news! I scored a free non-running ICE bike to pull parts from. Makes putting a second one together easy. I think a lot of people just run these bikes as far as the original oil and filter will go. :lol:
Image

I mocked up a set of plastics on it to see what that would look like for fun. I think it's probably more unique and cleaner looking without but this looks different
Image

A little vid on fab work up to this point.

User avatar
shortcircuit911   1 kW

1 kW
Posts: 346
Joined: Feb 19 2010 1:24pm
Location: Antioch, CA

Re: E-Mini Pit Bike

Post by shortcircuit911 » Jan 12 2019 1:00pm

Awesome video man. Really clean work and nice tools, love the laser and that cnc bender.

Grantmac   10 kW

10 kW
Posts: 680
Joined: Oct 22 2018 12:43pm
Location: Victoria, BC

Re: E-Mini Pit Bike

Post by Grantmac » Jan 12 2019 1:09pm

That's an inspirational build.

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Jan 14 2019 2:16pm

Did some more fab work this weekend and got the rear swing arm mocked up with a shock. Also made some parts for the other 2 bikes. A little bit closer.

Image
Image
Image
Image


User avatar
Chambers   10 W

10 W
Posts: 90
Joined: Nov 11 2011 8:01pm
Location: Brisbane

Re: E-Mini Pit Bike

Post by Chambers » Jan 14 2019 5:14pm

Looking good! Can I ask how you have attached the swing arm? Are you just using bolts?

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Jan 14 2019 5:39pm

Chambers wrote:
Jan 14 2019 5:14pm
Looking good! Can I ask how you have attached the swing arm? Are you just using bolts?
Thanks! The swing arm is attached with a heim joint/rod end. They are very strong, easy to replace pivot components so I like to use them for this application. They also allow for slight front to back adjustment.

User avatar
Chambers   10 W

10 W
Posts: 90
Joined: Nov 11 2011 8:01pm
Location: Brisbane

Re: E-Mini Pit Bike

Post by Chambers » Jan 14 2019 6:00pm

Thanks mate.

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Jan 21 2019 1:47pm

I powder coated the frame and misc parts this weekend and did a little bit of the assembly work. I have to get a few more hardware pieces, the controller, battery, and make some side panels.

Image
Image
Image
Image
Image
Image
Image

damirsky   1 W

1 W
Posts: 63
Joined: Dec 03 2014 11:28pm

Re: E-Mini Pit Bike

Post by damirsky » Jan 26 2019 1:12am

i like everything around here: the design, the workshop, the little riders, the dog. :bigthumb:
please keep going.

User avatar
trazor   100 W

100 W
Posts: 159
Joined: Jan 13 2015 10:48pm
Contact:

Re: E-Mini Pit Bike

Post by trazor » Jan 30 2019 2:02am

Incredible build!
Which program are you using to CAD design? I saw your videos and could not identify it.

User avatar
Chambers   10 W

10 W
Posts: 90
Joined: Nov 11 2011 8:01pm
Location: Brisbane

Re: E-Mini Pit Bike

Post by Chambers » Jan 30 2019 4:50am

Looks like solidworks to me.

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Feb 12 2019 7:59pm

Thanks guys. Yeah it's solidworks.

I took one of the seats apart and shaved a ton of foam off of it to see how low I could get it for a smaller/lighter configuration. Should work well on the little bike with 10" wheels and light forks.
Image
Quick mockup, looks like it'll be perfect.
Image

First pack to test the bike with. 14s5p with Samsung 30Q cells w/ 50amp continuous, 100amp max BMS.
Image
Image
Really happy with the fit in the frame. Room for 2 more packs in there, plus the charger if needed. :bolt:
Image
Image
Image

Mocking up the controls.
Image

Next up is trying to figure out the correct hall sensor/phase wire combination for the GNG motor with Kelly KBS-X controller. Anyone already know? I tried matching them all color to color and it's not right. Looks like I am going to have to go through and test all 36 combinations to figure it out. I tried a few that I thought might work and I am still getting hall sensor errors.

Isn't there a way to auto-detect on the KBS? I thought so. I don't see it in my software options but I have an older version of the software and Kelly's site has a bad link on their KBS-X software download page right now. Of course that happens when you need it. lol

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Feb 22 2019 3:20pm

Did some functional test wiring and testing on the throttle setup. Finished welding out another frame that will get an LMX motor in it. Same motor chassis and mounting pattern, just a lot wider. I will make a bracket to mount the hall sensor throttle box this weekend and get some other details done like routing a long hydraulic line for the rear brake and rear axle tensioners. Not far away from a test ride of the first one.


User avatar
Chambers   10 W

10 W
Posts: 90
Joined: Nov 11 2011 8:01pm
Location: Brisbane

Re: E-Mini Pit Bike

Post by Chambers » Feb 22 2019 9:55pm

Looking good man! :bolt:

User avatar
Chambers   10 W

10 W
Posts: 90
Joined: Nov 11 2011 8:01pm
Location: Brisbane

Re: E-Mini Pit Bike

Post by Chambers » Mar 16 2019 2:51am

Any progress?

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Mar 19 2019 6:42pm

Just got home from vacation in Utah. I finished the first bike and we did some riding. Really satisfied with the power. I had to turn down the max current down to 35% on the Kelly to make it appropriate for my son who is still learning. The KBS controller I am using will do 100amp burst for 30 sec. I tried riding it like this and it was really fast with 160lb person on it. Picks up faster than my big bike despite the big bike having 130amp burst KBS controller and a much larger BHT motor at a much higher 72 volt nominal. The tire size on the bigger bike and less reduction have a big impact. The little bike is only at 52v but the smaller tire and more reduction really make it kick off the line. Enough to power straight into a wheelie with me on it when turned up. It is only topping out at about 27mph which is about as fast as they need for now. With it turned down, the max I have seen is about 29 amps battery current measured through the Luna meter. I can't wait to see what the bike with the LMX motor and 72 volts going in is going to feel like. :twisted:

150amp main breaker and a 300amp disconnect switch tucks inside of the frame.
Image
Image
Image

hall throttle sensor pulled by standard cable throttle.
Image

bike with shaved seat
Image

chain adjuster
Image

Programming controller
Image



2 more to finish now!

User avatar
Chambers   10 W

10 W
Posts: 90
Joined: Nov 11 2011 8:01pm
Location: Brisbane

Re: E-Mini Pit Bike

Post by Chambers » Mar 27 2019 12:39am

Haha that looks like awesome fun!

User avatar
standfast   100 W

100 W
Posts: 124
Joined: Apr 25 2014 8:29pm
Location: Los Lunas, New Mexico

Re: E-Mini Pit Bike

Post by standfast » Jul 10 2019 10:29am

Took the bike with us camping this weekend for my son to ride. He has been riding it around the house quite a bit and it has been solid. Still on the small battery pack and only 31A peak current measured. That is plenty for him as he only weighs 50lbs.

Haven't finished the other bikes yet. About to get back on that soon. So far so good.


User avatar
armandd   100 W

100 W
Posts: 107
Joined: Jan 18 2018 4:46am
Location: Malaysia

Re: E-Mini Pit Bike

Post by armandd » Jul 15 2019 11:41am

That's a really solid looking mini bike, amazing :bigthumb: :bigthumb: :bigthumb:

mxs   10 W

10 W
Posts: 76
Joined: Mar 21 2018 5:04pm

Re: E-Mini Pit Bike

Post by mxs » Jul 17 2019 9:00am

Beautiful work. Would love to have one for myself, to play around the house.

Post Reply