Yuba Mundo V3.3 - is now Stoke Monkey ready : )

[eBikeStore]

Hello Yuba Mid Drive Folks,

ryan suggested I post here to let you know about the conversion kit I am making for the Yuba V4 to make it Stoke Monkey compatible.

Essentially, is it a Stainless Steel bar with flanges that mounts on the center stand tab on the lower end and the brake bosses on the top. The SM then uses the extracycle clampset on the stainless steel bar - plug and play.

The jig to make the conversion piece was made by Brett Flemming of Efficient Velo Tools http://www.biketoolmaker.com (His helmet mirror is the best on the market)

Attached are some photos from a set up I did last night.


View attachment 1

If you are looking for a Stoked Yuba, I can send you the stainless steel bar ($65) or the whole Stoke Monkey setup with bar.($1350) Supply is running low on the Crystallyte 407 controllers, so if you have your own controller, that will save you $100. Note: these prices do NOT include the battery. On this bike, I used an eBikeKit 22A controller with a handlebar switch to limit to 250 watts for the times I want to conserve my battery. Lyen's programmable controller would be ideal.

For the throttle, I suggest a half-twist. To make the shift levers buttery-smooth I filed the corner back top of the up-shifter so it clears the split twist throttle.


Brakes - I highly recommend upgrading to the disc brakes. Avid BB7s are ideal. However, Yuba has indicated that the 203mm rotors will not work on the rear and suggested the 180mm rotors instead. I will post photos of the 180s after I have installed them on the Yuba I am putting together tomorrow.

Battery - on this build I used the eZee 36V 14Ah Li-Po flat pack with cordura carrier. It fits, but is a bit awkward. I am considering asking Ping to custom make a battery that will fit perfectly into the same space so that I can them make a removable alum box that we could paint to match the frame.

Of interest: The customer for the bike pictured asked if we could match the frame color for the Stoke Monkey. If this important to you all? should I ask Todd if that is an option? (I would do the painting, but I don't want to screw up his branding.) Yuba will be sending me the specs for the paint on the frames in the next week and I will post that information here...

PM me if you want one - for questions, please post here so all can see and make suggestions.

Best,

Wake
The eBike Store http://www.ebikestore.com
Portland, OR

 

[ryan]

It's a beautiful build, Wake. Great work. You're an inspiration to us here. Thanks for posting this for us.

Now, I have a bunch of questions for you.... :wink:

1) Can you tell us a little about the stoked mundo? What can you tell us about the performance before we get an opportunity to build one ourselves?

2) I'm sure you've been approached for a solution to Todd's freewheeling crank. Have you any thoughts on how to accomplish the option of not pedaling with assist?

3) Do you happen to know if you can buy the SM bracket separately from the motor? (I'm considering using a variety of different motors in a similar build)

4) Beautiful work on the steel bar, but why didn't you attach it directly to the rear dropout?
4b) Or the seat tube? (I can imagine that this would pull the wrong way and might also compress/weaken/destroy the seat tube. Is that right?)

5) What type of wood did you make the running boards out of on Drew's build? Do you have any rough dimensions on that or did you make it up as you went? (I'm considering putting a double deck full of LiPo for my build so I'd like to have a rough idea of how much will fit)

6) What are you going to do differently next build? And what were the roughest spots with the conversion?

 

[eBikeStore]

Hey Ryan,

I apologize for the tardy reply - Everytime I have built one, dog gone it, someone has come and bought it, so I made one for myself that is not for sale and have been parking my Sprinter van. Further, I had to confer with Clever about selling the bracket, etc by themselves - but more on that later, lest I get ahead of myself...

1) Can you tell us a little about the stoked mundo? What can you tell us about the performance before we get an opportunity to build one ourselves?

Sure, a great deal depends on the controller. The Crystallyte 407 controller is similar to the 22A eBikeKit infineon that I am using. Overall, I have 120 miles on the bike (1 weeks worth) and have been averaging 21 watt hours per mile. While I am not a speed freak (I have yet to have a customer whose bike goes over 25mph avoid a hospital visit for more than 6 months) The EBK Controller gets me up to about 16.5 with ease and then the power tapers off considerable. I would like to reach 20 mph with ease and then taper off... I am considering upgrading to a programmable Lyen 9 fet controller

2) I'm sure you've been approached for a solution to Todd's freewheeling crank. Have you any thoughts on how to accomplish the option of not pedaling with assist?

I have mentally designed a double freewheeling bottom bracket, but truth be told, I love the way the Stoke Monkey works. It rides like a bike and as I have thought more about it -and logged more miles- I have determined that I strongly prefer pedaling with the Yuba. Down the road, I might consider asking eZee to make a 48V high torque motor for the V4, but I am in love with this bike as it is.

3) Do you happen to know if you can buy the SM bracket separately from the motor? (I'm considering using a variety of different motors in a similar build)

Yes, the bracket and clamping set are available sans motor. Todd is adament that the Stoke Monkey is silent, so he prefers a direct drive motor, but I am toying with an eBikeKit geared Motor as a weight saving measure. That being said, I can offer the bracket to on ES for $150. The clampset is $199.

4) Beautiful work on the steel bar, but why didn't you attach it directly to the rear dropout?
4b) Or the seat tube? (I can imagine that this would pull the wrong way and might also compress/weaken/destroy the seat tube. Is that right?)

I looked at those options... It was difficult to clamp on the rear stay and keep the SM chain line in order, further, I plan to have our little daughter on the back of my Yuba very shortly and so I sought to have the motor as tucked away as possible.
One the seat tube, I also looked at this option - -
[*]Reverse Mounting: It is not difficult to change the phase/hall effect wires to make the motor spin in reverse. However, the freewheel threads on the motor are standard and as such, the freewheel would spin right off or I would have to change the motor cover to one with a reverse threaded freewheel and then use a Currie reverse threaded freewheel. Lastly, because the front derailleur is a bottom pull, the reverse Seat tube mount would have required changing the front derailleur.
[*]Forward Mounting: front derailleur still an issue. Cringed at the idea of my pantleg anywhere near the Monkey's teeth - they are sharp & pointy!

5) What type of wood did you make the running boards out of on Drew's build? Do you have any rough dimensions on that or did you make it up as you went? (I'm considering putting a double deck full of LiPo for my build so I'd like to have a rough idea of how much will fit)

Drew made the running boards. However, historically, Yuba has provided drawings of the Utility Deck and Running Boards for all of their models, so I will sketch up the running boards and post them here in the next few days.

6) What are you going to do differently next build? And what were the roughest spots with the conversion?

In terms of rough spots, there really weren't any. The actual conversions have been incredibly smooth. A few smaller points.:
[*]Greg Mayer, a former yuba employee and friend showed me his preferred location of mounting the controller up and out of the way between the rear fender and utility deck - I really like that and will be using it going forward.
[*]I am not in love with how the flat eZee 36V 14Ah battery mounts - I like to be able to quickly remove the battery for charging and would love to get away from the power cord I have had to rum to my detached garage to juice up. - I am looking into other options
[*]In my last conversion, Mac Peebles had me upgrade the brakes to Avid BB7 Mechanical Disc brakes - 203mm in the front and 185mm in the rear (203mm rears don't work well with the frame) - While I find the V brakes that come with the Mundo more than adequate, the BB7s absolutely rocked

 

[eBikeStore]

Some Photos from the latest build.

 

[ryan]

Thanks Wake! More photos please! It's a beautiful build.

I just picked up a gently used Yuba Mundo v2 to test how I like the cargo bike style of riding. I got it really cheap so when I'm ready for the full on v3 or v4 mid-drive build I'd be able to sell the v2 for more than I got it for plus move forward with the far more expensive build with complete confidence that I'll love the result.

I'll post a build thread for my v2 Mundo soon enough. I'm going to move my 5304 over plus 72v20Ah.

 

[chroot]

Hi-

The pictures looks sweet, My girlfriend and I are in process buy a Yuba Mundo v4 in blue color bike this saturday and I desire buy a StokeMonkey however their price tag is so steep. I determine asked Ilia Brouk to see if there any alternative mid-drive mount kit so I could use any high torque DD hub motor I.E. xlyte 5304 or HT35.

Ilia warned me that StokeMonkey design is very nice however it does requires pedal while it runs. He suggested me that run in front wheel as use Direct Drive hub motor.

Is there any kind using the freewheel allows no need pedaling while the motor runs?

Let me know thanks.

 

[urbancommuterstore.com]

Here is my custom mid-drive set-up for the Yuba Mundo V3.3, but this will also work on the V4. I'm hoping to release the final version of the m-drive pretty soon
The hub motor drive is totally independent from the cranks. The cranks do not turn while you power up with the motor. My systems has freewheel gears in a shaft. I do not use freewheel cranks so the front chains do not turn while using hub motor power. The motor is independent from the cranks as well. If you choose to use pedal power only, you do not turn the hub motor, so there is totally no drag on the pedal. Feels normal all the time. List price will be under $1,000 for sure. Complete with mount, gears, hub motor, motor controller, thumb / twist throttle. CA is optional.

 

[chroot]

Hi-

The picture you showed, It really so beautiful Yuba cargo bike and Whats the cost for the complete mount kit without the motor. I was going get xlyte powerful 5304-5305 hub motor and just need the complete mount kit like you said it totally independent from the cranks. That's what I am interested.

Let me know 8)

 

[urbancommuterstore.com]

I did some fitting today on the mount, the xlite 5304 will not fit the mount. Diameter of the hub is too big, it will hit the seat and chainstays. Motors will fit are BMC, MAC and Aotema rear hub motors with 135mm spacing. BMC and MAC have fast wound motors, but Im not sure if it will come close to what the 5304 delivers. I have not tried it yet. The main advantage of the M-drive set-up is being able to climb steep hills efficiently with cargo.

 

[snowranger]

That's the nicest mid drive setup I have seen in a cargo bike. It sure solves a lot of mechanical issues. Are you planning anything for xtracycles or big dummys too?

 

[ryan]

That is just beautiful, UC. Please share more of how you solved the freewheel issue.

Also, I may be interested in a setup as well. Can you show some video of your mid-drive in action?

 

[deVries]

That is just beautiful, UC. Please share more of how you solved the freewheel issue.

Also, I may be interested in a setup as well. Can you show some video of your mid-drive in action?

Please show pics/video up close so we can see behind the motor mounting plate & what's happening 'there'. It seems you show only one chain going back to the rear gears for the derailleur, but I can't see what the motor chain is doing/going & how it works.

Thanks!

 

[snowranger]

It appears there are three chains involved and 2 freewheels on a single shaft.

 

[tfahrner]

Nice work, UCS!

 

[chroot]

I am going to use the 9c motor or a xlyte hs35 motor. I am sure that it will be able fit and how much cost of this kit? Please let me know.

 

[chroot]

@UC- Whats the status on your new development product mid-drive kit? We already reserved and pick up Yuba Cargo bike tomorrow. I am kind of eager getting the Yuba bike equip the mid drive system.

Last question, How fast when putting low gear 11T at full WOT on flat road and planning use 48v20Ah (2x batteries 40Ah)?

Let me know thanks 8)

 

[urbancommuterstore.com]

@UC- Whats the status on your new development product mid-drive kit? We already reserved and pick up Yuba Cargo bike tomorrow. I am kind of eager getting the Yuba bike equip the mid drive system.

Last question, How fast when putting low gear 11T at full WOT on flat road and planning use 48v20Ah (2x batteries 40Ah)?

Let me know thanks 8)

Top speed w/ 36V12A SLA, rider weight 200lbs + 28lbs battery weight + tools = 22mph. I figured if I used a lighter battery pack, it could be around 23mph. My goal with the drive system is to be able to carry heavy loads going uphill. So far, going up a 12 deg incline with 180lbs of cargo (2 big kids), went up easy with out pedaling. You can actually play around with the gear ratios of the system. That is the beauty of it.

Any hub motor having a diameter of 190mm and up will not fit in the motor mount. I designed it to accommodate only smaller diameter hub motors. I have tried fitting bigger ones, like the 9C and newer Xlite with 200mm and up diameters, it will not fit.

Im choosing between a MAC 500W 8turn motor with a 9FET Infineon Controller 30A 36V to 72V max or an Aotema DD motor. I am currently using the Aotema and so far, it has been well. The new and improved MAC geared hub motors will be tested soon. I am hoping to gain more efficiency with the MAC, maybe an additional 3miles from what I am getting now with the Aotema which is only 18miles @ full throttle using 36V12A SLA batteries.

The kits will be on sale 1st week of October. Thanks


I will be posting some videos soon of the Yuba m-drive soon. Update: I was able to mount my chain tensioner for the front crank, so you can use all three chain rings. I had a lot of options but I opted for the most simple but effective tensioner with parts readily available from your LBS.

 

[chroot]

What a beautiful piece of the mid-drive system. Out of the curiosity, how much did you get the efficiency output? My 9C usually give me about 27-30 watt per mile.

 

[John in CR]

UrbanCommuterStore,

Don't you think $980 msrp is being a bit greedy for a hub motor+controller that is under $100 wholesale + 2 freewheels + 1 small axle + 3 bike chains + 1 small mounting bracket + 1 thumb throttle ? Don't get me wrong, I like the kit other than that the mounting bracket doesn't accommodate larger diameter hubmotors and regen isn't possible, however, real advancement of the cause requires minimum pricing not maximum. Follow China's example of what is possible with ebikes in less than a decade.

 

[jimw1960]

What is the advantage of going with the Stoke-Monkey kit? Seems like it would be cheaper, easier, more space efficient, and fewer moving parts to fail if you just went with a hub motor.

 

[John in CR]

What is the advantage of going with the Stoke-Monkey kit? Seems like it would be cheaper, easier, more space efficient, and fewer moving parts to fail if you just went with a hub motor.

Variable gearing to handle big loads and tackle hills so steep that cars can't go up them, all with relatively low power. The variable gearing also permits better efficiency and performance, all while retaining the relative silence of a hub motor. If you have the space, the drawback is introducing more points of wear and failure, though the're readily available bike parts.

 

[chroot]

It is better than Stoke-Monkey kit because the Stoke-Monkey runs motor and it required pedaling same time (No freewheel) so UC made his product that comes with completely freewheel (no need pedaling while motor running).

The advantage is FREEWHEEL. That's it. 8)

What is the advantage of going with the Stoke-Monkey kit? Seems like it would be cheaper, easier, more space efficient, and fewer moving parts to fail if you just went with a hub motor.

 

[Chalo]

It is better than Stoke-Monkey kit because the Stoke-Monkey runs motor and it required pedaling same time (No freewheel) so UC made his product that comes with completely freewheel (no need pedaling while motor running).

Lame.

One of the chief advantages of Stokemonkey is that because you pedal along with the motor, you automatically shift to keep the motor in its efficient RPM range (if the bike was set up appropriately for your usual cadence). Make it freewheel the pedals, and you lose that advantage, plus the range and performance advantages that you get by contributing work at the pedals.

It's already a motor assisted bicycle. How lazy do you really need to be?

Also, derailleurs don't work right when the entry and exit angles of the chain are that different from the angle the derailleur hanger was intended to provide. Shifting will be relatively impaired and wear and tear will be increased.

Chalo

 

[urbancommuterstore.com]

It is better than Stoke-Monkey kit because the Stoke-Monkey runs motor and it required pedaling same time (No freewheel) so UC made his product that comes with completely freewheel (no need pedaling while motor running).

Lame.

One of the chief advantages of Stokemonkey is that because you pedal along with the motor, you automatically shift to keep the motor in its efficient RPM range (if the bike was set up appropriately for your usual cadence). Make it freewheel the pedals, and you lose that advantage, plus the range and performance advantages that you get by contributing work at the pedals.

It's already a motor assisted bicycle. How lazy do you really need to be?

Also, derailleurs don't work right when the entry and exit angles of the chain are that different from the angle the derailleur hanger was intended to provide. Shifting will be relatively impaired and wear and tear will be increased.

Chalo

Hi Chalo,

How do you like your Stokemonkey? It was one of my inspirations why I came up with the mid-drive for the Yuba. I really think that the stokemonkey is a great product.

Re: Derailleurs on the mid-drive, I have logged almost 850Mi of off-road riding, only maintenance I have done is the usual cable tension adjustment. I don't understand what you mean by the exit and entry angles of the chain and how it affects the shifting performance of the derailleur or where you got this theory. Based on the 850mi of riding on single track and fire road that I have logged, I never had any shifting issues. Out of the tests that I have logged, I don't count the 1800mi of pavement that I have rolled on with the kit installed. Btw, I have been running on 72V for the last 5 months, still no issues. The only problem I have is my car doesn't get used anymore.

Anyway, here is a link to a video I made to show the shifting and angles that you were mentioning in your post, the rear chain is around 10 links short in this video, that was the only set I had that time when I shot the vid. It makes the rear derailleur stretch out too much causing it to look weird. Thanks

[youtube]R5ZdbAGKJ90[/youtube]

Sonny

 

[dogman dan]

Where do you get a stokemonkey kit nowdays anyway? I thought they went away.

Pedaling in the wrong gear ( too high) is the source of many problems people have with cylcone kits, I think. Wouldn't the pedals always turning tend to lead the rider to selct too high a gear? It would at least give the rider a clue what gear he'd selected at least, but wouldn't really encourage slecting a gear the motor likes.