SIKK fat wheel bike with trailer with Bafang 1000W

[SDharlie]

So my latest build is a SIKK fat wheel bike which I bought online for $399. The reason for this bike purchase was because I'm 6' 2" and most times when sitting on a bike I feel like an uncomfortable giant. This bike frame comes in a XXL size so even with the seat lowered almost all the way down I can barely touch my feet on the ground which I love. Also I'm a below knee amputee and if the frame is smaller when my prosthetic side pedal is at the top I have to bend my knee in a very uncomfortable position but with the large frame that bend in my knee is not so extreme. This is my 4th e bike build and when I build bikes I plan on NO peddling. When I want a workout I do workout but riding an e bike for me needs to be all about fun an NO sweating. Just silently cruising along. Originally I built this bike with two 1000W hub motors, 2 controllers, 2 accelerators but it was heavy and the steering felt bulky. One of the motors died so I decided to get rid of both hub motors and install a Bafang 1000W mid motor. I have to tell you, unless there is some major breakthrough in hub motors I will never ever use one again. Mid motors are the way to go. This is my 2nd BBSHD build and these things are bullet proof.

[SDharlie]

I purchased a 48V-20ah battery online before Luna Cycles had the current selection of batteries. I wish I would have purchased a 52V but maybe in the future. I wanted to keep as much weight in the center of the bike so I fabricated and welded to the frame a metal plate to hold the battery and used matte black Rustoleum paint to keep the same look.

[SDharlie]

I often like to ride with my Fiance on the back or bungee a milk crate on the back to carry whatever I can so I fabricated a large rear rack with 1/2" square metal tubing and diamond plate. When I carry a passenger they sit on a folded towel or small cushion but I plan to make a custom cushion that is more comfortable. I made some passenger foot pegs that slide right onto the axle. I purchased a set of LED lights from Harbor Freight for $6.50 each and I'm using an adapter that downgrades the 48V to 12V to make the lights work.

[SDharlie]

So far I've ridden this bike 15 miles with zero peddling and still had more juice left in the battery. I'm guessing it will get 20 miles per charge on flat"ish" terrain. I've ridden it though quite thick desert sand and yesterday me and my Fiance rode together on the beach for about 5 miles and it goes through the soft sand surprisingly well. My next addition will be Luna Mighty Mini 30 tooth chain ring. The bike does great with the stock chain ring but this bike is not build for speed, its built to carry and haul. I'll use my Mt bike with the new BBSHD for speed when I want it.

[SDharlie]

Next I will be welding up a removable tow hitch which will attach to the bike rack at three points with nuts and bolts for easy removal. I've never been a fan of the trailers that attach to the side of the bike or even worse the the seat tube (which will make my rear rack useless) I purchased a welding cart at Harbor Freight for around $50. I did this because all I needed from it was the very heavy duty wheels, very thick spokes and bearings. I'm guessing I could put around 300 pounds in this trailer, not that I ever intend to. I installed the same Harbor Freight tail lights keeping with the 'theme'. I made a custom attachment which allows the trailer to move left, right, up and down. Also at the rear of the trailer I intentionally left the four pieces of the frame about 1" longer than the rest so that I could stand the trailer up on its back when in storage.

[ironjack]

Looks real nice! I'm with you on the pedaling aspect.

I've currently got hub motors but the bafang bbshd looks really interesting. Currently researching my next donor bike. Have you ever heard of Day 6 bikes?

[SDharlie]

No I have not but I just checked out their website. They look very comfortable with that fat seat with a backrest. I prefer the mid motor because on my fat wheel bike the wheels are 26" but with all the extra rubber the wheel actually measures around 29" so for a hub motor to turn a big wheel like that and specially with all the extra heavy parts Ive put on it makes it harder for a hub motor to move the wheel with each revolution. The mid motor doesn't care what size wheels I'm using and I can use the bike's gears to help the motor depending on the grade. Its a no brainer unless the hub motor one plans on using is very powerful. I'm still using a 750W hub motor with 36v 10ah battery on my small three wheeler but the front wheel is 24" tall which is much easier to make turn.

[ironjack]

Yeah my fat bike has a 3000w mxus hub with a 60v 20ah battery pack. Mucho fun.

How hard is it to weld something onto the frame?

[SDharlie]

Its pretty simple. I started with a piece of cardboard then I bought the metal, cut it to size with a chop saw with a metal blade. then I used a table grinder to cut voids out of it so it would fit into the space I wanted. I used a grinder with a sanding pad on it to get ride of the paint on the bike. Then I put the bike on a work table, leveled it out then used a level on the metal plate and welded it. Them I used a brush with mat black Rustoleum to make it look like part of the bike.

That bike looks like a sweet setup.

[Haprunhy]

Thanks for posting this. I too just bought a sikk bike and had plans to convert it into an e bike. I was just about to buy a hub motor and battery on ebay. This is my first build and I was just going to wing it. But after seeing this and your mid drive advice I'm now thinking about going that direction. We need to talk :-) maybe exchange emails ?

[SDharlie]

Haprunhy: from your profile picture looks like you got the single speed with the coaster brake? It's better to use the book thing motor with gears.

[Haprunhy]

Yeah. Okay then, so a hub is the way to go for my bike ? Any suggestions ?

[SDharlie]

Yeah. Okay then, so a hub is the way to go for my bike ? Any suggestions ?

I would direct you hub motor questions to someone else. The only ones I've purchased were off eBay out of China. They run well but die after some time.

[SDharlie]

This last weekend I bent and cut some diamond plate to go around the battery to match the top of my rear rack.

[Christian Livingstone]

Hey,

Nice use of diamond plate. That, and the expanded metal are favorite materials, for me.