My first "real" electric bike project. 72V @ 310Amps

steam25

100 W
Joined
Apr 9, 2012
Messages
257
Location
Shenzhen China
hello crew,

many of you know i am living in china. so i have access to all the wonderland factorys with cool electric vehicle stuff.
after many builds of "normal" bike conversations to high power electric bike i decided to cooperate with some chinese factory here and build my first real electric bicycle.

WHAT DOES THAT MEAN?
custom frame with my own design, components and ideas.

WHY BUILD IT?
because we love it and i think its time for a high power fun machine with a reasonable price tag.

photos will follow soon but here is a first scratch about the frame...


first you all want know some specs i think.

- 72V 20s lipo battery with 35Ah and 10c continuous discharge rate @ 350A (charge rate max 35A @ 1c)
- Cromotor V3 with reinforced internals, 150mm dropout, 16mm axle, 70-80km/h
- Kelly KEB72101, 450A,10KW, E-bike Brushless Controller/ Regen
- custom full suspension frame with integrated torque arms and enough space for battery, controller, small charger and stuff
- 26" motorbike rims, 2 speed for pedaling, hardcore 12V front lightbar and integrated LED light for rest of the bike

of course its a long way to go and first results will follow in a month but i made a good start and figure out alot problems. i open this topic to hear some feedback or ideas from you guys.

something about the idea from myself: i will build 3 different versions. this is the biggest. there is another one just for long range which will look like a normal bike (3 battery will be inside the frame) and last but not least a light small efficient mid motor bicycle, based on the second bike but just 2 instead of 3 battery and 48V.

for this big monster i will use very high power lipo cells from japan which i already test a long time in my other scooter project: http://endless-sphere.com/forums/viewtopic.php?f=12&t=58220&start=50#p875612

after over 12.000km and nearly 500 cycles of charge/discharge i can say these batteries are awesome! even without BMS i can charge or discharge them as hard as i want. since month they are absolute perfectly balanced and i am really impressed. price will be around 400$.
with the frame i try to keep the point of weight low as possible. the bike will be much bigger and longer as a normal bicycle and a hybrid between bike and motorbike. maybe make a version without pedals and just something to put your legs on later?
front fork will be downhill from DNM with 203mm. name is USD-8 (anybody experience with this brand?)


after test it for some month i plan to sell it.
of course many people not interested in a "ready to go" vehicle so i also plan to sell the frame only so you can build your own bikes.
same with the battery.

ideas? opinions? questions? here you go!
 
today i went to the bike factory. i agree about the long frame and we find a solution to optimize the design. higher angle for batteries would be a good start i guess?

another thing: today the final size of the battery came out. and i think i will make a custom 21s because we have enough space. that will give a little more range and speed.
fully charged the pack will have 89V instead of 84V.
i tried this out in my scooter and the kelly can handle it without problem.
:mrgreen:
 
yep. aluminium.
i try to find a design, different from others but lets be honest: we are limited here. it will be similar but no mid drive motor. no round shapes. i want it futuristic and modern. hard edges and diamond like shapes.
next week the battery should be done and i will go to the frame factory. change the design a bit here and there. figure out how to decrease the overall length and stuff.
 
Subscribed. Looking great
 
short question guys: i want use the DNM USD-8 fork.
what diameter and size i should tell the frame factory to use for optimal fit?

i saw others also use same fork.
i can buy stuff here directly from factory extremely cheap. but there are no instructions or other infrmations.
 
i'm use 24x3 with this fork :
jFdYFTvmLQQ.jpg

lB20YHVHAdI.jpg
 
hey guys,
thank you devman for the information! thats EXACTLY what i needed. :shock: :idea:

yes i am also happy finally can make a real product. it will be crazy. motor and controller will arrive next tuesday. photos will come! :arrow: :mrgreen:
 
today some photos while making the 72V 35Ah lipo battery...

motor and controller will come these days.
battery comes with 2 more balancer plugs.
first 2 balancer going to the BMS for charging and balancing.
discharge without BMS because we will go over 300Amps here.
second balancer plugs are going to a display near handle bar so we can monitor each cell while accelerating and charging.
later i want to use a small app and a bluetooth PCB. plug balancers in, download the APP. put your phone on the bike and see your battery in real time.

so far so good. the next days will be more exciting
 

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battery is done.

72V 20s (10c - 1c)
35Ah
350A continuous discharge
35A charge

later i will make a 21s or 22s version to get little more range.
 

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good. thanks for that info. i never saw a real raptor frame.
i think my frame will be even a little longer because of the battery and huge controller.
i am thinking about to use 24" rims instead of 26". but first i wanna try the 26 laced motor. maybe its perfect. that bike should accelerate like a spaceship. top speed is fun but going 80km/h on a bike is dangerous. 65-70 would be enough for me. and if i can do rolling burnouts on gravel i will be more happy.

more to come
 
If you make the width of your photos 800 pixels or less they will show.
 
I see you are using a Kelly controller. I thought you were not happy with the performance of the Kelly in your scooter project?
 
excactly! but to test the motor with high power i will use kelly cause it have temp sensor connection already build in. and fits to the motor.
we are planning to build our own controller with bluetooth adapter for mobile phone app.

oh and last but not least: the first kelly blows up in a spectacular plasmaball. after talk to kelly long time, they send me a complete new controller and THAT one works much better. so i think the really horrible take off performance that time was fault of a already broken controller when i bought it new.

this motor is high torque low speed.
scooter motor is high speed low torque. --->bike should take off MUCH better with nearly same power as the scooter.
we will see what happen.


and thanks for the photo tip! i will reduce to 600p
 
hello crew,

big news today and i am really excited. just back home from 4 different factories.

FRAME:
we talk alot about the final design. there will still some upcoming changes but it gave me a huge smile to see the design on paper for the first time.
View attachment 8
View attachment 2

SHOCKS:
for the front i already bought the DNM USD-8 which comes in a kind of golden brown color.
but as arrived the factory i saw this green beauty and i ask wether they can make another color...for example blue, which would fit PERFECT to my chrome blue design later. they agreed to make a custom sample for me in blue! :mrgreen: :p

IMG_1687-Optimized.JPG

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the rear shock will be this huge DNM. 320mm motorbike shock. enough for 700kg.
IMG_1680-Optimized.JPG
IMG_1667-Optimized.JPG
the first prototype of my bike will be in chrome blue with white motor and white rims. rest parts like the rear fork stay in aluminium silver.
go get my idea i think the bike will be similar to the new SLS electric:


battery is done and ready to build in. its a 20s 35Ah for testing first. later i will change to 21s.
and sorry for double photos. the webside is out of control and i am too tired to find out why. :mrgreen:

seat post will be downhill with remote. nothing fancy but i want be able to change seat while riding.
all cable and wire by the way will be inside the frame.


so far so good!
controller already arrived with the motor together but it was delivered to wrong place so we can get it to the factory tomorrow. when these last parts arrive we will start to build the first frame. make some changes here and there to fit the huge controller and other stuff.
as the frame is done it will get this awesome chrome paintjob and the start to buidl up the bike.
hoooooooot daaaaaaamn! :mrgreen:
 

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Those green Forks look dope! They are very reminiscent of the finest forks around ATM....
DVO Emerald DH
dvo_emerald-2013_cg-bike-and-fork-details_by-adl-1542.jpg
 
hi guys,
next tuesday i should get some photos of the custom fork in blue.

have a question: i need a brutal disc brake system. double piston.

ANY SUGGESTIONS?
 
tektro hd710

http://www.tektro.com/_english/01_products/01_prodetail.php?pid=155&sortname=Disc&sort=1&fid=1
 
thanks dev!

seems a little weak. i mean something like this: Hope tech v4
http://fstatic3.mtb-news.de/f/8n/i0/8ni08ppo64jy/large_k-KPH_2950.JPG?0

inner cooled discs: http://fthumb0.mtb-news.de/cache/670/auto/1/1/fstatic3.mtb-news.de/f/5n/m5/5nm5kb4o3b9p/large_hope-8.jpg

steel flex: http://www.x-bikers.ru/board/all/118362_2.jpg

look at these beauty!!!
large_k-_-17.jpg

anybody experience with them?
 
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