Help me covert my Yuba Mundo v1.1 to a ebike

[trex]

I'm new to the ebike world, and I have been looking at my opinions. Because of my weight...230 Lbs. I think that my Yuba Mundo cargo bike would be the best bike to convert into a ebike. With that said, I would also like to use a non-hub motor drive, because of the large hills, and 7 miles, between my house and all the stores located in Redding calif. Any ideas? Here's a pic of my bike... it will carry up to 400 Lbs. of cargo. I paid $300 for it used, so I don't want to spend more then $1000 to get it up and running. Right now I have a motorcycle and a 3/4 ton truck, I would like to sell the motorcycle and park the truck...and use the cargo bike for runs to the store.

 

[amberwolf]

Your best bet for a non-hub drive on a medium-low budget is probably to go with a very Stokemonkey-like setup: using a cheap hubmotor in the frame to drive the cranks/drivetrain. Even a fairly small motor can do quite a lot of work thru the drivetrain; some people use the actual stokemonkey setup to go up hills they cant' pedal up (as a very recent post in one of the SM threads describes).

You're going to want to work out the numbers on how much power it is going to take to go that distance on that terrain with that much weight, so you know how many Wh of battery you'll need worst case. There are some online calculators to show how much power it takes to climb specific slopes with various loads.

Also, are you planning on recharging at the store-end of the trip, while shopping, or will you need full round-trip capability?

 

[trex]

Your best bet for a non-hub drive on a medium-low budget is probably to go with a very Stokemonkey-like setup: using a cheap hubmotor in the frame to drive the cranks/drivetrain. Even a fairly small motor can do quite a lot of work thru the drivetrain; some people use the actual stokemonkey setup to go up hills they cant' pedal up (as a very recent post in one of the SM threads describes).

You're going to want to work out the numbers on how much power it is going to take to go that distance on that terrain with that much weight, so you know how many Wh of battery you'll need worst case. There are some online calculators to show how much power it takes to climb specific slopes with various loads.

Also, are you planning on recharging at the store-end of the trip, while shopping, or will you need full round-trip capability?

Here's some information that I found today... Because of a supply issue, the Stoke Monkey is not currently available. Please know that we are working on it and hope to be able to offer the Stoked Yuba again in the near future.

Because it transmits the power through your drive train (your gears) the Stoke Monkey is a great way get around town...even if you live in San Francisco!

Stoke Monkeys have conquered hills as steep as 28% (think Olympic Ski Slope). If you are not climbing the alps - or even if you are - the Stoked Yuba has the power to move you, your kids and/or your cargo whenever the road takes you.

How? In Partnership with Yuba Mundo,Clever Cycle and Efficient Velo Toolswe have designed a stainless Steel adapter that fits the Stoke Monkey beautifully within the frame of the V. We have access to batteries that fit into the space above below the cargo deck and above the Stoke Monkey.

The bottom line... they want $1,300 for the "stroke mundo" kit...but it's not avalable right now.

Here's another one I found from a guy in calif. Here's his web site, http://gobiketrip.com/blogs/urbancommuter/08-07-2011/my-yuba-mundo-m-drive-electric-bike-conversion-kit
And some information from his web site...I have finally built my mid drive conversion kit for the Yuba Mundo V3.3 - V4. It is mounted in frame using my patented hub motor mount. The system is independent of the pedals, so when you throttle up, your pedals will not turn with the motor. You can coast with just the motor for as long as you like. The motor's gear is connected to a single cog freewheel mounted on a jackshaft then turns a fixed gear on the same shaft to drive the rear freewheel cogs. The front cranks are also connected to a single cog freewheel on the main jackshaft. You can still use all three chainrings in the front cranks. I installed a chain tensioner to address the chain growth issues when dropping down to the smallest chainring. I have been riding and testing the system for 2 months now, out in our mountain bike trails in Santa Clarita Valley. This thing can really haul up the steeps without stalling. You may find it weird that I am testing it off road, but to me it's logical that way. It's only out in the mountains where I can test on really steep hills. Maybe, in a month or two, I will make a trip up to San Francisco to test in the really steep ascents around the city. One of the advantages of the conversion kit is that the gear ratio can be tuned to work in different road / trail conditions. If you live in a hilly area and carry heavy cargo on your bike, you can gear the system to be at it's most efficient setting by just swapping out a drive gear on the shaft. The conversion kit is a direct bolt on to the Mundo frame. No need for modifications, maybe except for 1 part where in I had to drill out and widen one of the holes for the side loader mount in the frame. I found out that there were some quality control issues in the frames because I saw this problem in some of the bikes I sold. The holes don't line up properly, so you need to enlarge the hole a bit so the bolt holding the mount can go through and be installed properly. Other than that issue, all went smoothly. I am using an Aotema Direct Drive rear hub motor. Top speed is 21 to 22mph. Battery I used to test are cheap 36V 12A Sealed Lead Acid Batteries that weigh a ton! I wish I had some lightweight Lithium batteries at my disposal, I could have gone faster, farther than what I got on the heavy batteries I used. I was able to travel 22 miles around our trails with a mix of pedal assist and just pedaling alone.

My goal for this project was to make an efficient conversion kit that can really climb hills without draining excessive juices from your power pack. To be able to climb longer and travel longer distances with cargo. To be able to have the drive system independent from the front crankset. I believe that I was able to achieve all goals. I have a Happy Mundo now.

I will be testing it one more month, and if budget permitting, send out some kits to friends to test and get feedback



So, based on what I found on the web, there are some nice kits out there for the Yuba Mundo, but both are over $1,000. I am just wondering if there are other opinions out there for the Yuba Mundo, and the cost is under $1,000!

Anyway, I need a bike that can make a round trip of 20+ miles, with a 5% grade for a 1/4 mile, going to town, and a 7% grade for a 1/4 mile coming back home.

 

[amberwolf]

That's why I suggested a SM-like setup, because it will do what you want, and can be built for a lot less than the actual SM (without battery, which you will have to work out how much you need to find out how much that will cost).

If you're looking for a pre-built kit to do what you're after, it's almost certainly going to cost you more than your budget, and possibly without even a basic battery.

But you can build what you're after if you have some tools and skills to make the mounting brackets for the motor itself. There are DD and geared hubmotors that are cheap enough, less than $200 (possibly a lot less), that will do the work needed. Here on ES (and elsewhere, as you've found), there are various examples of how to install them into the driveline of a bike (or trike) in different ways, depending on what you want it to do and perform like. At least one of the ES examples is on a Yuba Mundo (or was it a Surly? Either way it's similar enough to make adaptation easy). Other ES examples are different bikes and at least one trike, using various motors and mounting methods.


I myself am planning on such a middrive:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=31255
using probably a 9C DD type, but possibly a small Fusin geared hub, and at some point a large brushless powerchair motor (just to see what happens). I don't have details of mounting yet, but as I am suggesting you do, I myself will be plucking various bits of the methods others have used to design my own mountings, when the time comes.

 

[Whiplash]

VERY nice I like the jackshaft idea! I am doing a similar design on my build...

http://endless-sphere.com/forums/viewtopic.php?f=28&t=34158

 

[stoney]

The only problem with the info that you gave him was that other yubas you show are for later models 3.3 and 4. The early yubas don't have the space in that area. (You could put it in the triangle but you may have issues with being pinched while riding.). If you already considered this excuse my input

 

[trex]

The only problem with the info that you gave him was that other yubas you show are for later models 3.3 and 4. The early yubas don't have the space in that area. (You could put it in the triangle but you may have issues with being pinched while riding.). If you already considered this excuse my input

Good point, Mr Stoney... But I'm still going to look for a e-motor that runs off the crank, for my 1st year-generation Yuba Mundo. I really don't want to use a hub motor, but I may not have an opinion. Or I could get the my 4" grinder out and start cutting and removing the lower support tubbing, and make room for a stroke mundo "type" setup. :lol:

 

[amberwolf]

Depending on the size of the motor you use, you don't necessarily have to remove any frame bits. If you calculate out your power requirements and find you can use a small-diameter motor like the Cutes or one of hte various smaller geared hubmotors, and don't need to mount anything on teh spoke flanges, you can even decrease the motor diameter by perhaps up to 2cm by removing those flanges (this has also been done on some of the middrive setups).