Sikk fat cruiser + Cyclone 3000W + custom battery box

theGoPedal

100 mW
Joined
May 14, 2011
Messages
37
Location
Kansas City, Missouri
Hey Guys,

Been a while since my last post but I still lurk almost every day and I'm still building bikes. I'd like to share my latest project:

View attachment 14

The bike is a Sikk fat cruiser - an oversized 3-speed internal fat tire beach cruiser made out of steel. I chose this bike as a donor for a few reasons:

1. I wanted a bike big guys could ride. This bike is designed for guys 5'9" and up and can handle up to a 250lb rider.
2. I loved the idea of a 3-speed fat bike.
3. I really liked the oversize beach cruiser look and I wanted to work on a bike that was less complicated than my full suspension Kona.

Upon receiving the bike, overall I was happy but I did find it was lacking in a few areas. I found that in order to keep the bike affordable, the bike's designers had to cut a few corners on components. The stock tires and brakes were of low quality. I upgraded the tires to Vee Rubber V8s and upgraded the brakes to Avid DB1 hydraulics. Also, the bike has a 1 inch head tube instead of 1.125, which really limits the choice of forks. This is probably a remnant of the bike's beach cruiser heritage, but still too bad. I decided to leave the stock fork on for now. Lastly, the bike came with oversize ape-hanger handlebars which I didn't like, so those were swapped out with 5-inch risers.

All that said, you get a oversize steel frame fat bike, set up with decent rims and a SA 3-speed internal for $500 shipped to your door. Not bad.

View attachment 13

I was very impressed with Kepler’s ideas for making custom battery boxes out of aluminum and plastic. I basically copied his style with a few modifications. The aluminum (0.063 in.) came from a local metal shop and the plastic (0.125 in.) for the sides is standard stock from Grainger. I also purchased a small sheet metal bender to make the bends and a mini table saw to cut the plastic (both from Harbor Freight). The box is large enough for the battery and all the connectors. The wires enter through the bottom and on the front of the box is a panel mount XLR port for charging.

IMG_20160427_103648.jpg
IMG_20160427_122113.jpg
IMG_20160428_151034.jpg

The battery is a pair of 6s 16AH Multistars wired in series for 12s. I added a 60A lipo BMS from Greentime and built a custom harness for it. Connectors are XT-90 anti-spark for the discharge wires and XT-60 for the charge wires.

IMG_20160501_133635.jpg
IMG_20160502_123931.jpg
IMG_20160502_125646.jpg
IMG_20160508_165832.jpg

Installing the Cyclone was fairly straight forward, but did require a few mods. The bottom bracket of the Sikk bike is 120mm, so I had to get some longer bolts and extra spacers to make it fit. I was also concerned that the extra width of the BB would put too much stress on the bolts, so I cut out some tabs out of some scrap to secure the motor to the bolts on the non-drive side for extra support. I used a second hose clamp instead of the large zip-tie to secure the motor to the frame. The hose clamps were also wrapped in heat-shrink so they wouldn't scratch and better blend-in with the rest of the bike. I swapped the 44t inner chainring with a 36t to slow the bike down a bit.

IMG_20160514_151944.jpg

The ride is really enjoyable. The cyclone is a bit louder than my MAC but I'm getting used to it. Plus I've read the gearbox gets quieter as it wears in. The extra volume of the fat tires take a little getting used to on the street but do a good job taking the edge off the bumps in the road. I did limit the speed to 25 mph as I feel this is fast enough for the frame and stock rims. With the 3-speed I can easily climb any hill in my area. Acceleration is quite brisk.

Other parts: Luna Cycle e-brake sensors, Luna Cycle rear LED light, Ebay 10W headlight.

Still to do: The plastic sides of the battery box are easily scratched, so I plan to cover those with some vinyl ‘carbon fiber’ wrap. I want to get a few more accessories like a cell phone bracket and cup holder. Maybe some fenders.

I’d like to figure a way to make the battery box more watertight. Any ideas for that would be greatly appreciated.

I didn’t really plan for it to have a retro motor-bike look, but that’s how it turned out. I think the finished bike is really sharp. Thanks for looking. All feedback is welcome.

More pics:

DSC04071.JPG
DSC04072.JPG
DSC04075.JPG
DSC04081.JPG
 
Hey theGoPedal, that's one nice looking ride and a really neat installation. Love that batt box. To seal it, maybe you could use a generous bead of silicone on the metal case with cling wrap on the side plates. Assemble FINGER TIGHT until the silicone is firm then tighten up a bit more without squeezing it out. Once set, remove the cling wrap for a nice gasket.
I reckon some nice shiny chrome or alloy fenders would really make it pop.

AussieRider
 
Wow, that's a nice bike. Looks great and probably goes pretty good too. Nice work.
 
Really like this machine :D ,well executed.
 
BMS is fine. Seems to work as advertised. It has LEDs to let you know when each cell hits 4.2V, so that's nice. I haven't tried LVC; I never plan to take these cells below 3.5V so hopefully I'll never need it.

For me, the hardest part was soldering the main wires. But I'm getting better at it. For that job I recommend at least a 60W iron and flat tip.

Here's the link if you're interested:

http://www.aliexpress.com/store/product/16S-Li-ion-Lipo-Batteries-Protection-Board-BMS-System-60V-67-2V-50A-Continuous-Discharge-Current/313864_32263328170.html
 
hi guy I saw a list of links of the parts you used but can't seam to find it again can you post or tell me where i can find
 
I really like what you did here with this Sikk and the Cyclone 3000W.

I do wish I could know how loud and what sort of sound a Cyclone build like this would create. Did you post a video of it running anywhere?

Also, could you also have cut down the BB a bit?

https://electricbike.com/forum/forum/builds/ebike-building-directions/15004-cyclone-3000w-on-sikk-fat-bike-with-custom-al-plastic-battery-box
and
http://www.ebikekc.com/sikk-fat-cruiser-retro-motor-bike/
 
Gary, the parts list is on the electricbike.com site: https://electricbike.com/forum/forum/builds/ebike-building-directions/15004-cyclone-3000w-on-sikk-fat-bike-with-custom-al-plastic-battery-box . It's the second post.

g725s, thanks, it's so much fun to ride. I don't have a video but I think you can find videos of other cyclones. I don't think it's too loud, but others might have a different opinion. Yes, I think you could cut down the BB a bit if you need but you need to watch the crank clearance and don't cut off too many threads.
 
I just bought the cyclone 3000w kit for my Sikk UFO but just found that there will be some chain work any ideas on this matter like size, type?
 
Garysb said:
I just bought the cyclone 3000w kit for my Sikk UFO but just found that there will be some chain work any ideas on this matter like size, type?

Garysb, lease post your build . Very interested in what you do with the Sikk UFO and the Cyclone. I would really like to eventually do a Cyclone build probably by the start of summer after tax returns.
====================================================================================================

TheGoPedal, did you ever figure out the Pedal Assist setup? Or a Shift Sensor? Or a Brake Sensor? And are you planning on adding a display eventually?

And would the 120mm BB Cyclone version been a better option? I assume you only went with the smaller BB version because Luna had it at a reasonable price?
 
Pedal assist - yes I did get it working but I'm not happy with it. It seems to be either 'on' or 'off'. No modulation at all. Not sure if maybe I mis-wired it. It just got really cold and icy here so I can't get out and do further testing at the moment.

Shift sensor - don't have one.

Brake sensor - I'm using the ones from Luna: https://lunacycle.com/parts/cyclone-parts/ebrake-sensors-for-cyclone-kit/

Display - I'm simply using my android phone with a speedo app as a speedometer. The throttle that came with the Cyclone kit has a voltage display so I'm also using that. Eventually I'd like to upgrade to a bluetooth controller, but I'm waiting for the tech to mature a bit.

120mm BB - Yes I think that's a better option. I went with the 110mm from Luna because it was handy and worked OK for me. But I think 120mm would be better as the spindle is longer.
 
Back
Top