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

In hope brakes are no sensors for regen.
You will have to do something like this :
index.php
 
yes, thats hall sensor and magneet - for analog regen in max-controller .
 
dnmun said:
the BMS in that picture will not handle 350A. i doubt if it will handle much more than 35A. someone stripped out all the mosfets. that is cheaper than cheap.

He already said he isn't discharging through the BMS.


Looks like an awesome project, and you're lucky to be living in the motherland of ebike parts and awesome food. :) I love China and frequently visit Beijing, Shenzhen, Gan-Zhou, and HK. Are you near any of those cities by chance?
 
guys i have a question:

is anybody from you interested to buy this frame once its done?
battery included so you just throw a motor, controller and wheels on.
price not sure now but it will be not crazy expensive.

i need some feedback here so i can prepare to build more and get better prices later.
 
today i got message from the fork factory. my custom blue downhill fork will be ready in 1-2 weeks.
 

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hello crew,
sorry for the delay.

many things happen, but also many thing DONT happen. the frame factory is very slowly. he promised me many times 25-30 days. now 2 month over but he doesnt even start to build the frame. yesterday i drive to shenzhen and wait 2 hours in his office. the boss never showed up, his phone is off. because he was drunk and forgot our appointment. welcome to china! :roll: :evil:

lets come to the good news: fork is done and look incredible! custom made in taiwan. i also went to the factory from DNM yesterday to pick it up. its a beauty and i am very happy.

and the new light arrived last week. after long search i found a nice slim profile 12V car LED lightbar. before i try 60W but its too big and heavy. so this time i want go smaller and thinner.
result is this 30W cree flood/beam combination lightbar. energy consumption is just 1,2 ampere and its about 3000 lumen. which is far more powerful than any bike light. as you see the lightbar will fit the front fork. i will build an adapter made from aluminium.

before somebody suggest to improve the connection between frame and rear fork. thats what i did already. the build in torque arms also improved now.
factory promised to start build the frame tomorrow. photos will follow.
 

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steam25 said:
hello crew,
the boss never showed up, his phone is off. because he was drunk and forgot our appointment. welcome to china! :roll: :evil:

looks like Russia :)

Nice lightbar, can you give a link ?!
 
i buy it directly from factory. no link. i know the boss. sure you can buy it somewhere online but i dont know where. be careful for fakes. these kind of stuff is often fake.
but if many of you interested we could make a group order here? i often do this in other forums.
 
motor is finish spoked in. also front wheel.
its on the way back to me now. looking fine i think
 

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steam25 said:
i buy it directly from factory. no link. i know the boss. sure you can buy it somewhere online but i dont know where. be careful for fakes. these kind of stuff is often fake.
but if many of you interested we could make a group order here? i often do this in other forums.


It's almost the same: http://www.aliexpress.com/item/Hots...oad-led-light-bar-for-utv-atv/1722215601.html

Edit:
i think i found it: http://www.aliexpress.com/item/7-8i...eam-Offroad-Light-12V-24V-For/1463276020.html

Edit 2:
ebay: http://www.ebay.co.uk/itm/Super-Sli...r_Truck_Parts_Accessories&hash=item5d514a7e41
 
its not exactly same, but nearly. lumen is lower because think they use cheaper components. i also cant get it for this cheap price.
but yes. you can buy that. if you guys buy, please make sure you get the FLOOD only reflectors.
otherwise theres a too bright spot in middle. i also changed mine to flood only and its better now.
:mrgreen:
 
today i start make some first cratches for the second bike.

it will look much more clean, like a normal MTB. it will have 3 batteries inside the frame. BMS and controller will be also inside frame.
i plan to build 3 different types from the same frame.

- 72V 19Ah lipo 5000W continuous full suspension frame 65km/h high torque hub

- 48V 13Ah lightweight 350-500W middle motor/hub, 25-45km/h

- 48V 27,2Ah long range allrounder 25-45km/h should result in 150km a charge


i see many ebikes here in china with only 1 battery and its ALWAYS upright. so everybody can see from the side with a short look its an ebike.
i want to go totally different and make the profile same flat from side like a normal bike. to get enough capacity, every tube will have a very thin battery pack inside, connected to 1 BMS to make it a big single battery.
72V version will become a 60A continuous BMS which should be enough to go crazy with a big hub. 150mm rear fork with adapter to 135mm and of course integrated torque arms.
all wires, break cable, shifter cable and other stuff like BMS+ controller will be invisible inside the frame.the whole bike is aluminium and will help to cool the components.
LED lights will be invisible integrated in the frame as well.
first prototype will be 21-22"
i want to make a mini version later.

suggestions or ideas?
 

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Great plans! It will be interesting how you manage the wiring and tube access and weight and strength :mrgreen:
 
all 3 tubes will have removable side panels. small bolts for stability :idea: 8)
it will be very easy to access all parts.
wires might have a extra tunnel inside which is also same time reinforcement for the frame.

dont worry i got this! :mrgreen:
 
today i bring one of the rims to my local bike shop.
throw on the biggest tire i can find to see what it looks like and wether it fit :mrgreen:

put in lightweight FOSS flatless inner tubes.

motor will follow.
 

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310A pushed thru .08 ohm of phase to phase resistance is almost 8kw of copper losses. Time to reevaluate expectations and change the thread title.
 
true john,
i also plan to build on version with the bigger 10KW motorbike hub. laced in 24" rim.
but then without pedals.
i wanna try the 3kw first. reduce the power to 150-200A. see what happen

thanks for your reminder :idea:
 
Sweet builds, I'm jealous of your blue forks!

Re: the minimal frame, I've been down this road before (with one of my custom frame prototypes here: http://endless-sphere.com/forums/download/file.php?id=92074 ) and it's quite hard if you keep the outer measurements as minimal as possible. Wiring up multiple packs becomes quite tricky unless you have big battery door to allow easy access, and then it weakens the frame. I'm only using the single downtube section for batteries in this and getting the cells and series/parallel wiring into the frame through a small opening is a real chore.

As for what John said about dumping 8kw of heat into the motor, that's only if you sustain it, and for a bicycle build your motor isn't going to want to pull anywhere near that sort of power.
I'm running "only" 150A (battery, 350A phase current) on my latest offroader with 24" rims and on full throttle launches it only stays over 120A for a second or so then settles back down to sub 100A. I dare not speak the words that 300A is overkill :twisted: but yeah, if you're used to riding heavier scooters at high speeds you'll find you won't need so much current in something that's more a bicycle (or pretending to be! :p )
 
problem is still the bad kelly performance.
full throttle from the line the kelly start with about 20-40A until reach 20km/h. then climb slowly up to 300A after reach 70km/h.
thats safe but boring.
 
great build, can you send me a fork? i will find a friend to buy one if that makes it a group buy :wink: i think you need to fix that kelly, other people have received damage controllers from them (or damaged them installing :wink: ) and had poor performance. im extremly happy with mine. kbl 96251 on cromotor 17" wheel

fany is extremely helpful

also have u checked for bad connections eg phase or battery interconnects mabye your wheel is just too big
 
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