Cyclone 4kW mid-drive self-engineered project

tubeglower

10 mW
Joined
Jul 13, 2017
Messages
30
Location
Catalonia //*//
Hello there,

this is my first thread in ES, and after enjoying a lot some of the great builds here, I decided to post mine, hopefully it can be of help for someone and I can get some extra advises in the journey...

First, I needed to define what I wanted when I started to think about this project, here some points:

- I wanted an e-bike plenty of power and not spending a fortune, that is why I selected the cyclone kit, 4kW motor and BT controller.
- The power setup includes 18s lipo pack (10000mAh) which should be capable of 4.3kW peak (with the supplied 60A controller). I could, eventually, parallel two packs to double the range).
- Pedelec + Throttle (moto style), so PAS implemented.
- No big money on the donor, that would need to be heavily modified.
- Decent suspensions and brakes to handle the power. So proper shock and fork and hydraulic brakes are a must.
- I should try to handle from the beginning the twisting torque of the motor to assure a stable and straight motor chain-line, which will save a lot of problems later when handling that many watts.
- "Monocoque" frame to put everything inside and protected (battery pack, cables, connectors), and to assure very high stiffness.

The first task was to find a donor frame. It is actually plenty of possibilities out there, and I did not need a lot of time till I found the donor. A New Old Stock Alpinestars RSA840 frame. It was a very cheap option (@ 40€) even if it did not include the shock in the price, I already had a Cane Creek DB Air shock collecting dust. I also bought a cheap second hand Rock Shox Totem fork (good stiff 40mm stanchions spring fork). Whit the Cyclone kit at home I could start working...

I did not take any pics of the frame before chopping it, but it was like this one:

ALPINESTAR RSA840.jpg
 
Are you interested in the 4kw motor or the 4kw coaxial drive?
Looking at the BB of your bike this popped in my mind:

https://electricbike-blog.com/2018/03/10/rebel-scum-ii-2500w-ultra-max-ludicrous-diy-torque-sensing-full-susp-10sp-ebike-2805-w-out-battery/

You could possibly pull this off. I don't get what you mean under "chopping it up".

The 4kw cyclone with its extra 30% torque over the 3kw is powerful enough that it does not need a second reduction at all, it has comparative torque to the BBSHD (100nm+) but with a wider power band, 0rpm to 700rpm at 72v, over the BBSHD's 0rpm to 150rpm at 52v. You just need a good low gearing, like 22t chainring and up to 42t rear, in the lowest gear that will still take you to 30mph with wheelies on demand.

The PAS is pretty rudimentary on these drives. It is pretty much an on-off switch with full or no power, accident prone. It is so bad, I paid for it but don't use it.

Setting up two batteries parallel is pretty tricky, they will go out of balance and will fight each other. Better to have a big pack that can supply enough amps and if you really need another small one to extend range, possibly in your backpack. You will end up using the one you mount on the bike anyway because it is less of a hassle.
 
Hi Tommm, thanks for your link. I did not know about the ultramax. I already have got the cyclone, 4kW motor (apparently similar or same than the 3kW). By chopping the frame I mean removing basically the front triangle and only use the rear suspension system, I will post pics asap.

The PAS is something I want to implement, I will play with what cyclone has delivered and see what I can get out of it... :roll:

Bench testing it...

https://www.youtube.com/watch?v=-8whR8X9tCQ
 
plans going forward...

IMG_9525.JPG

IMG_9681.JPG

Now I will need to play a bit with cardboard templates... :lol:
 
Tommm,


Setting up two batteries parallel is pretty tricky, they will go out of balance and will fight each other. Better to have a big pack that can supply enough amps and if you really need another small one to extend range, possibly in your backpack. You will end up using the one you mount on the bike anyway because it is less of a hassle.

Tricky??

This declaration is a crock of S.... I run parallel LiPo packs all the time and have no trouble.

Fighting??

Hardly. It is the micro-micro voltage difference between packs that drives them to equilibrium. This voltage signal difference is always working when the packs are connected and contributes little to cells going out of balance.

It is the Pack charging that can become tricky. Discard bad cells.
 
DingusMcGee said:
Hardly. It is the micro-micro voltage difference between packs that drives them to equilibrium. This voltage signal difference is always working when the packs are connected and contributes little to cells going out of balance.
I meant two complete batteries of 18650 cells, the batteries do not balance between themselves, only whatever is inside them. They need to be the same composition, wear level and need to be charged to the same level.
 
A parallel battery pack is a possibility (always monitoring the packs, and balance charging). But to be honest, I will start with a 18S LiPo pack, so let's postpone the discussion till that happens... :wink:
 
Today I was able to do some more stuff...
Cardboard, scissors and hot glue with some enjoying time with a good friend and my favorite welder (he is a veteran frame builder, and will be in charge of all the welding work).

View attachment 3
View attachment 2
IMG_9684.JPG
 
Nice looking workshop and bike project.
There are more powerful Cyclone motors then their 4kw models.

I bought the 4kw coaxial Cyclone, it had the power to climb anything with my fatass on the bike from a complete stop.
I just didnt like the gear noise because people can hear me coming from behind them. I prefer stealth as much as possible, I prefer to look like a bicycle from all angles but that is hard to do so I settle for looking like a bicycle from the front and back. I dunno if I will sell my C4K or not, missing two of the long gear reduction case bolts is all, they are somewhere. I am currently making a mid drive bicycle from a cruiser but with a direct drive mxus 3000w and its a learning experience so I can do a mxus 5000W on a different bike that has tubes apart of the frame where the battery goes.
 
markz said:
Nice looking workshop and bike project.
There are more powerful Cyclone motors then their 4kw models.

That is true, but as a first e-bike project I am happy enough with the cyclone 4kW... :wink:
 
Wow you really did chop it up. Are you welding alu with alu? How heavy is that frame part now?
 
Tommm said:
Wow you really did chop it up. Are you welding alu with alu? How heavy is that frame part now?

Yes, Aluminium TIG welded.

I don't know the weight, but I am aiming for around 30kg for the complete rig. I had to use 2mm gauge alloy sheet, when my initial thought was 1mm or 1.5mm, but the supplier did not have it in stock (at least not the proper alloy), and now is pretty much summer vacation weeks in my area, I did not want to wait since I have also some off days to put on this project.

Weight is critical, but I think I can afford 1 extra kg in the frame with the 4kW of power... :lol:
 
You opened a holes on it, you think it will be big enough for the battery? What will put cover them with? Will you use hinges?
 
Tommm said:
You opened a holes on it, you think it will be big enough for the battery? What will put cover them with? Will you use hinges?

I hope the hole will be enough, I plan using three lipo packs (6S 10000mAh) that I've already ordered to Hobbyking.
For the cover I plan using dzus fasteners, no hinges.
 
I also made an effort to improve waterproof capability of the motor and controller by adding some sealant to the mating surfaces


IMG_0135.JPG
 
Starting the assembly. I do need some proper e-bike brakes, but so far I think I will try with some shimano that I do have sitting around. I go for 26+ wheels, since they have close to 27" circumference when using 3.0 tires. I do not have more room available in the shingarm and fork, so even being a 29" lover, I will have to accept the compromise of cost vs preferences.


IMG_0054.JPGIMG_0081.JPGIMG_0113.JPGIMG_0114.JPG
 
tubeglower said:
Starting the assembly. I do need some proper e-bike brakes, but so far I think I will try with some shimano that I do have sitting around. I go for 26+ wheels, since they have close to 27" circumference when using 3.0 tires.

26" is better than 29" for high powered ebikes, the longer spokes of the bigger wheel act as a force lever when trying to transfer the power from the hub to the rim, making them and the holes more prone to a mishap.
 
Weekend has been very fruitful, and the bike it is alive :D . I managed to put together pretty much the whole bike, some points that are still missing:

- Install PAS
- Figure out how to implement e-brakes.
- Fabricate the cover for the battery box
- Start to play with the parameters of the controller, to find the optimum set of figures for pedal assist use and moto use.
- Intal gearsensor or not?

View attachment 3View attachment 2IMG_0142.JPG
 
SwampDonkey said:
Sweet bike! Where did you get the 4kw kit? Ive seen the standalone motor but not kits offered.

I think there are kits available now, just no one really knows about it.
 
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