Madsen cargo bike BBSHD kid hauler "Bucky the Bumblebee"

[Popstar]

With # of kids and friends growing, the ebike hobby had to evolve. Introducing Bucky the Bumblebee With seating for four kids in the back and power to make it over the portland hills, this thing is certainly fun.
Bike: 2011 madsen "bucket bike" cargo bike. Rear 20" tire, rear v-brake. Front upgraded to Avid BB7 disc from useless tektro. Added front rack kit from new madsen.
Motor: bbshd with lekkie 46t.
Battery: 33g 14s7p 21ah from em3ev. I made a sheath holder for it out of metal gutter/roof flashing and angle iron to go between bucket and seat tube.
Accessories: golf cart 48v to 12v. This powers the led strip lights for rear lights, front head lamps, and usb charger. With large bike, it has been 12v upgrade creep, looking into dash cam and any other crazy ideas.

The black and yellow bubble bee tape gave it extra flare my four year old liked, and that gave it the name.

View attachment 2

 

[999zip999]

Love

 

[999zip999]

So it goes 28 miles an hour ?

 

[Chalo]

So it goes 28 miles an hour ?

That would depend on the gearing. It has a 20 inch rear wheel, so I'm guessing probably not. If it has a freewheel with 14t high gear, the effective top speed is going to be much lower than if it has a cassette with 11t high gear

 

[Wheazel]

Nice bike! Looks very practical.

 

[Popstar]

Yes it can get up to ~28-30mph with the 46t front 11t rear gears with just a rider, even with the 20" rear wheel at WOT. That comes in handy at intersections and little else as speed obviously not really the purpose of this bike. It actually handles very well at speed, and being able to quickly get up to speed makes it possible to have multiple kids in the back safely without tipping overBraking that much weight on long winding descents going up over the hill into the city with a kid in the back is not as peaceful as my usual playgroup zip around. I really wish it had a way to fit a rear disc, or even a rear hub brake like some tandems.

 

[amberwolf]

Why can't it use a rear drum?


I assume it doesn't have disc caliper mounts to do the disc, but you could have those added to it easily enough, either by welding them on, or using some of the bolt-on ones that use the axle to secure them. THen you just need a disc-capable rear hub...but keep in mind that a disc wheel is a weaker wheel at least in side-loading than the one you have now because the spoke flanges are closer together.


Short of all that, you could just add a second set of rim brakes, basically the way I added them to my SB Cruiser's front wheel:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&start=475#p1289564

Might need something different in the manner of clamping htem onto your stays, but the parts needed are still the same. They also make actual adapters you can order for the purpose, if you don't want to DIY it.

Or you can cut the studs and some stay tubing off another bike and weld them onto your stays, like I did wtih CrazyBike2:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=12500&start=1000#p955999


There are a number of brake-handle solutions to make one handle control two brakes; dual-pull levers, adapters to pull two cables from one, etc. I just use two handles, works fine.

 

[Chalo]

Since you have a cassette, here's an option for adding a drum brake.

You can use a two cable lever like amberwolf says, or you can put the drum on a friction thumbshifter so you can apply it and leave it on until you're done using it (useful for long downhill grades).