My Yuba Mundo v2 Build (beta)

[ryan]

I built out a Yuba Mundo v2 last weekend using all the parts from my Marin Downhill Electric Mountain Climber.



Ingredients

• Yuba Mundo v2
• Crystalyte 5304 (rear)
• 18 FET Low RDS MOSFET Overclocker Ready LYEN Controller
• 72v20Ah (24S2P Headways)

I call this a beta build because I'm planning another build with a lighter and more middrive-friendly Yuba Mundo v3 or v4 if I like this build. Since it's my first time riding a cargo bike I didn't want go all out and discover I didn't like long tail bikes after all.

I love:

• No trailer necessary - everyone fits on the back! (except my 5 month old... I haven't figured a safe way for that to happen yet)
• Cargo - I fit 4 cases of beer in the back and had room for at least 2 more in the bags alone. I don't do groceries, but I do do beer runs.
• Stealth - The "before and after" shots look nearly identical. The bags hide the motor and the batteries. Only the controller is a little conspicuous.
• Fun - It's a lot of fun to ride. I can even sit on the rear deck and ride cruiser style (or even super man, if I'm up for it). The long tail handles more like a motorcycle (IMHO). Leaning more than turning.
• Different - I'm not a real attention seeker, but it's novel to get more stares than usual. So far I'm enjoying it.

I'm not so sure about:

• Weight distribution - ALL of the weight is in the back. I commute to work and have to drag my bike up a flight of stairs. I had a hard enough time getting it up the stairs without the x5 and 36 pounds of LiFePO4. I'm a bit nervous to even try. (I'm crossing my fingers that I'll be able to let the motor help climb the stairs, with all the weight back there it shouldn't slip.)
• Heavy - Not only is all the weight in the back, but the whole bike is just heavy. I had to pedal about 6 miles home this past weekend (yes, including the x5 cogging with my son on the back). I had down hills for part of the way, but even slight up hills are murder without power. Solution: More Ah. (that and a Yuba Mundo v3 or v4 is a bunch lighter)
• No Disc Brake Tabs - Bummer (I knew this going in, but still a bummer. I'm going to see about having someone weld on some tabs for me.)

Next Steps:

• Stoker Bars - [DONE]
• Lights - I still have my MagicShine on the Marin DH build
• Battery issues - I got two crappy cells (out of a dozen) from Headway-Headquarters I'm trying to work out a solution for. Held a nominal charge fine, charged up fine, but discharged super fast. Maybe 3Ah out of 10Ah. Toast. Bummer.

More Photos:
View attachment 6View attachment 4

 

[Richard N]

Congrats! Looks great, I'm looking forward to hearing about your range and speed when you get your cell issue sorted out. How far is your commute?

 

[jonathanm]

Bike looks great and the family shots look like a lot of fun!

Weight - any chance of building a little shelter outdoors for the bike? Just a lean-to with a roof over it might suffice depending on your weather and your neighborhood.....

Weight distribution - maybe put a bunch of cells up front like Oatnet did on this build here: http://endless-sphere.com/forums/viewtopic.php?f=6&t=24329

Ah - get more cells.....in order to make room, stop drinking beer and get a few nice bottles of wine, or a decent bottle of single malt.

 

[dogman dan]

Nice. But the stairs. Hoo boy. I can't pick my longtail up off the ground to weigh it. Move a battery forward for sure. Mine really improved when I did.

The yuba mundo is a great longtail! Cashless, I had to roll my own. Besides, I gotta have springs at my age. http://endless-sphere.com/forums/viewtopic.php?f=6&t=28389


Fell in love with the longtail instantly, despite the weight. But dread the day I pedal it home more than 1-2 miles. No way it will go on the bus or my car's bike rack.

 

[Lemlux]

Looks nice.

Where does the wife put her feet on longer rides? Not as far back as in the pictures I imagine.

"•72v20Ah (24S4P Headways)"

I imagine you mean either:

72v40Ah (24S4P Headways)
or
72v40Ah (24S2P Headways)

If the former, you, indeed, have a heavy bike.

 

[dogman dan]

96 headway cells would be heavy.

 

[ryan]

Lol. Indeed. Updated.

 

[georgefromvt]

Nice looking family but how about bike helmets for mom and dad? Hate to think Baby might have to go it alone if mom and dad get hit. You got a brain, use it, protect it!!

 

[Richard N]

I was just counting the spokes on your rear wheel, it looks like you are using 36, are you still planning on adapting your hub to use a 48 spoke wheel for your next build?

 

[ryan]

Nice looking family but how about bike helmets for mom and dad? Hate to think Baby might have to go it alone if mom and dad get hit. You got a brain, use it, protect it!!

Definitely. This was just a test run. If you'll notice I didn't even have the throttle on the handlebars yet.

 

[ryan]

I was just counting the spokes on your rear wheel, it looks like you are using 36, are you still planning on adapting your hub to use a 48 spoke wheel for your next build?

For this build I just switched my back wheel from my other bike. I'm still contemplating the 36-48 adapter. Or a mid-drive. I'm leaning mid-drive at the moment. But let me get a couple hundred miles on this one first.

But if you're going to make 2, be sure to make some extras for the rest of us!

 

[ryan]

Nice. But the stairs. Hoo boy. I can't pick my longtail up off the ground to weigh it. Move a battery forward for sure. Mine really improved when I did.

The yuba mundo is a great longtail! Cashless, I had to roll my own. Besides, I gotta have springs at my age. http://endless-sphere.com/forums/viewtopic.php?f=6&t=28389


Fell in love with the longtail instantly, despite the weight. But dread the day I pedal it home more than 1-2 miles. No way it will go on the bus or my car's bike rack.

The best part about this build was that I got the bike for a steal and it looks like I'll be able to offset the cost anyway with some tech help for the previous owner. It's the perfect beta bike! (until I learn how to weld)

 

[Richard N]

I was just counting the spokes on your rear wheel, it looks like you are using 36, are you still planning on adapting your hub to use a 48 spoke wheel for your next build?

For this build I just switched my back wheel from my other bike. I'm still contemplating the 36-48 adapter. Or a mid-drive. I'm leaning mid-drive at the moment. But let me get a couple hundred miles on this one first.

But if you're going to make 2, be sure to make some extras for the rest of us!

Well I'm back to work so building my my Mundo will be coming soon I hope. If anyone has a dead or even a live x5304 to donate for R&D, adapter rings could happen sooner...

 

[Rifle]

Ah cool. I'm helping a friend build the same thing basically. Yuba Mundo w/ a 2810R 9C and 2 36v 15ah Pings in serial. How many amps are you running?