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

urbancommuterstore.com

urbancommuterstore.com

10 mW
Joined
Dec 31, 2010
Messages
27
Location
Santa Clarita Valley, CA
Yuba Mundo V3.3 is now available according to the Yuba website. They made some changes in the frame to make it compatible with Stoke Monkey or some similar mid-drive motor set-up. I really think, with cargo bikes, mid-drive is the way to go. :D
 
I couldn't agree more! Make that cargo bike into a John Deer with hill climbing gears!

I'm going to talk to the folks at clever cycles soon, hopefully when I show them my build they might offer some suggestions for the best hub motor, or at least let me know what one they use. :)
 
I'm thinking of using an Amped Bike Geared Hub motor for my mid-drive set-up, Im not sure if this will work, but since it should technically have more torque, it looks ideal on paper. I will find out once I have set it up. I don't have the new frames yet, I will have them by next week. What do you think is a good gear to start with the freewheel? 14T or 16T? The biggest cog in the back will be 34T. Thanks.
 
urbancommuterstore.com said:
I'm thinking of using an Amped Bike Geared Hub motor for my mid-drive set-up, Im not sure if this will work, but since it should technically have more torque, it looks ideal on paper. I will find out once I have set it up. I don't have the new frames yet, I will have them by next week. What do you think is a good gear to start with the freewheel? 14T or 16T? The biggest cog in the back will be 34T. Thanks.
Click to expand...

I think the motor cog vs the rear cog is mostly a question of speed. Say you have a Shimano 14t-34t Megarange on the back. A 14t on the motor will give you the same gearing as if the hub was rear mounted. 14t-14t. 14t-34t is ~1.0-2.4 gear range. If you run a 16t on the motor, then you have ~0.875-2.1 gear range.

Let's say you pick a geared hub motor with a bolted down cover (Mac, Bafang BPM) rather than a spin on cover (Bafang QSWX). Then you work out some way of fitting a 16t fixed and 16t freewheel. Chainset to rear derailleur will be the same as stock. Motor to rear will be geared up slightly for a touch more speed when in 7th. Motor to rear will be 2:1 when in 1st for loads of hill climbing torque. Apart from mounts, chain runs and so on, the big problem is how to securely mount a fixed and freewheel on the motor. There's limited space and thread depth on the freewheel mount. And the thread direction means it will try and undo itself. I feel sure there's a solution though with a keyway or a grub screw or something.
 
jbond said:
urbancommuterstore.com said:
I'm thinking of using an Amped Bike Geared Hub motor for my mid-drive set-up, Im not sure if this will work, but since it should technically have more torque, it looks ideal on paper. I will find out once I have set it up. I don't have the new frames yet, I will have them by next week. What do you think is a good gear to start with the freewheel? 14T or 16T? The biggest cog in the back will be 34T. Thanks.
Click to expand...

I think the motor cog vs the rear cog is mostly a question of speed. Say you have a Shimano 14t-34t Megarange on the back. A 14t on the motor will give you the same gearing as if the hub was rear mounted. 14t-14t. 14t-34t is ~1.0-2.4 gear range. If you run a 16t on the motor, then you have ~0.875-2.1 gear range.

Let's say you pick a geared hub motor with a bolted down cover (Mac, Bafang BPM) rather than a spin on cover (Bafang QSWX). Then you work out some way of fitting a 16t fixed and 16t freewheel. Chainset to rear derailleur will be the same as stock. Motor to rear will be geared up slightly for a touch more speed when in 7th. Motor to rear will be 2:1 when in 1st for loads of hill climbing torque. Apart from mounts, chain runs and so on, the big problem is how to securely mount a fixed and freewheel on the motor. There's limited space and thread depth on the freewheel mount. And the thread direction means it will try and undo itself. I feel sure there's a solution though with a keyway or a grub screw or something.
Click to expand...

I saw in a thread that someone used an old bottom bracket cup to extend the threads of the freewheel mount. Screw in the 1st freewheel, then the bottom bracket cup (same thread count 24tpi) screws in the freewheel then the 2nd freewheel cog screws in it. I just can't recall the thread where I saw it. The problem is, even if I get to do the double cog on the hub motor, the fixed cog going to the rear wheel will unscrew itself eventually. Is there such thing as a reverse thread freewheel?
 
urbancommuterstore.com said:
I saw in a thread that someone used an old bottom bracket cup to extend the threads of the freewheel mount. Screw in the 1st freewheel, then the bottom bracket cup (same thread count 24tpi) screws in the freewheel then the 2nd freewheel cog screws in it. I just can't recall the thread where I saw it. The problem is, even if I get to do the double cog on the hub motor, the fixed cog going to the rear wheel will unscrew itself eventually. Is there such thing as a reverse thread freewheel?
Click to expand...

Yup, there's the catch. I think the fixed cog could be slimmed down depending on chain clearance so there's a bit more thread available to mount the freewheel. Although the freewheel will tend to tighten everything under pedal power, both cogs will tend to unwind under motor power. I think the solution is either a grub screw or a keyway. First mount everything up tight. The grub screw would involve drilling and tapping a threaded hole axially into the fixed cog shoulder and the mount. For the keyway, mark a point on the cog and mount and then grind a thin slot into both. Once it's all mounted again, fill the slot with a bit of square hardened steel.

What would you do with the reverse freewheel? They are available out there for BMX mounted on the left.
 
jbond said:
urbancommuterstore.com said:
I saw in a thread that someone used an old bottom bracket cup to extend the threads of the freewheel mount. Screw in the 1st freewheel, then the bottom bracket cup (same thread count 24tpi) screws in the freewheel then the 2nd freewheel cog screws in it. I just can't recall the thread where I saw it. The problem is, even if I get to do the double cog on the hub motor, the fixed cog going to the rear wheel will unscrew itself eventually. Is there such thing as a reverse thread freewheel?
Click to expand...

Yup, there's the catch. I think the fixed cog could be slimmed down depending on chain clearance so there's a bit more thread available to mount the freewheel. Although the freewheel will tend to tighten everything under pedal power, both cogs will tend to unwind under motor power. I think the solution is either a grub screw or a keyway. First mount everything up tight. The grub screw would involve drilling and tapping a threaded hole axially into the fixed cog shoulder and the mount. For the keyway, mark a point on the cog and mount and then grind a thin slot into both. Once it's all mounted again, fill the slot with a bit of square hardened steel.

What would you do with the reverse freewheel? They are available out there for BMX mounted on the left.
Click to expand...

Yes, both cogs will unwind under motor power and one of the more simpler solution is the key way. Regarding reverse thread, it was totally a noobie thought. I didn't figure out earlier that you also need to have the thread on the hub motor reversed (CW to tighten).

One more thing I discovered too, I forgot that the geared rear hub Amped bikes motor side plates are thread in, so it will loosed when load is applied. I might need to look at BMC instead but they are too much money.
 
Fixing and modding the freewheels/cogs to motors (with keys, screws, threadlockers) has drawbacks of non-standard replacement, and re-purposing.

There are a number of solutions for the freewheel/cog mount on a hub mid-drive: Jackshaft, Flopped motor with cog on disc mount, Reversed motor and idlers, etc...

Search on hub mid-drive, diy stoke monkey, dual freewheels, cyclone, jackshaft, etc.
 
Yehbut! IMHO, the Cyclone dual sprocket layout is the most elegant, simple and appealing mid drive solution when there's enough length between the crank and wheel. The problem is the gearbox and motor, not the layout. It avoids all the problems with freewheel cranks, powered cranks, additional jackshafts and so on. And that's why I keep persisting with the idea of using a conventional hub motor, centrally mounted but with two sprockets.

If you take the grub screw approach on the fixed gear, it's really doing very little damage to the hub. Because the hub is still rotating in the same direction, there's no need to get stuck with having to reverse the motor's internal freewheel.

If you use a DD hub, then reversing it is trivial. That opens up the possibility of making a disk side bolt on attachment with space for two sprockets and with a proper lockring. That's probably the best engineering solution but you need access to real machine tools to make it.
 
jbond said:
Yehbut! IMHO, the Cyclone dual sprocket layout is the most elegant, simple and appealing mid drive solution when there's enough length between the crank and wheel. The problem is the gearbox and motor, not the layout. It avoids all the problems with freewheel cranks, powered cranks, additional jackshafts and so on. And that's why I keep persisting with the idea of using a conventional hub motor, centrally mounted but with two sprockets.

If you take the grub screw approach on the fixed gear, it's really doing very little damage to the hub. Because the hub is still rotating in the same direction, there's no need to get stuck with having to reverse the motor's internal freewheel.

If you use a DD hub, then reversing it is trivial. That opens up the possibility of making a disk side bolt on attachment with space for two sprockets and with a proper lockring. That's probably the best engineering solution but you need access to real machine tools to make it.
Click to expand...

That's exactly right, I was thinking of an adapter that will bolt-on to the disc brake rotor attachment side that will have enough space for a fixed cog with a lefty lock ring, plus some spacers then the freewheel. We are only concerned about the fixed gear driving the rear wheel as it has the tendency to loosen under load. The freewheel connected to the front crank will not be a problem.

I still like your idea for the grub screw as it is the most simple modification, drilling and tapping the hole. I will probably do that first. :)
 
Hey Boostjuice, I just took delivery (and have started assembling) the exact same Yuba Mundo today!

I have put in a HS35 for the moment, and am about 80% through assembly (would be finished but my wife is making me clean the house, so right now I am typing this on the crapper with my laptop, hiding from her).

I will post photos when it is done, which should be tonight if she ever lets me out in the garage. It is awesome isn't it?

Are you really dropping a Collossus in yours?

I will be runnning mine on just 36 or 48v, as i have also bought two kids seats for it, and it is primarily for dragging my two kids about, so no need for colosus type speeds.
 
Mad-sick. Have i started a trend or something? Haha, i wouldn't have taken you for someone to be bossed around by the missus :lol:

Sweet frame for conversion for sure. No worries about battery/controller space. I'm yet to see a Yuba in Canberra. I've only seen the odd Surly big-dummy, Kona-Ute, Xtracycle.

Yeah, mine will be getting either a big Colossus or Jobymotor JM2 treatment. Depends on pricing/availability/testing by others which way i go. Money issues will mean this build will take till the end of the year due to being a relatively poor-ass uni student still.

BTW, i can replace your fet bank in your 24FET controller if you'd like. Intricate soldering is a large part of my job. We've also got all the test gear to interogate the circuit if other parts are damaged as well (although this can be difficult without a circuit schematic, which the chinese are not usually so forthcoming about)

I take it you got the complete bike rather than just the frameset? If you got the complete bike and dont have need for the 48spoke rear wheel due to your frock conversion, i might be interested in a little deal :mrgreen:

Anyway, will check in again tomorrow, im off now to get plastered and chase the ladies...
 
Anyway, will check in again tomorrow, im off now to get plastered and chase the ladies...
Click to expand...

Fark you Boostjuice and your happiness and freedom and being a student. It must feel so empty and superficial getting sauced and plugging Canberra's young ladies. I get to stay home, cook a cake for my 2 year old's birthday tomorrow, clean the house, and then maybe, just maybe if I am lucky get half an hour of my saturday night out in the garage. Married with children is awesome I tells ya....

i wouldn't have taken you for someone to be bossed around by the missus
Click to expand...

I used to not, but once you have children you lose all hand. I am now ruled with an iron fist, basically my testicles are kept in a case she has mounted on the setting. I have adopted the saying "What ever makes you least angry", as my general response to orders.

I will PM you about the wheel and offer of repair, I have a deal for you.
 
I'll be following this thread closely. I can't wait to see what you put together.

Can you give us any more detail on the plan? Also, are you planning on double free wheels for the mid drive so you don't have to pedal the whole time? Will you be fabricating the brackets to hold the motor or will you use some sort of oem stoke monkey adapter?
 
ryan said:
I'll be following this thread closely. I can't wait to see what you put together.

Can you give us any more detail on the plan? Also, are you planning on double free wheels for the mid drive so you don't have to pedal the whole time? Will you be fabricating the brackets to hold the motor or will you use some sort of oem stoke monkey adapter?
Click to expand...

No mid drive with this build. Derailleur chain will not last at all with the motor torque planned. Simplicity will be this builds virtue. LFP's 'pinky' Death-BMX proves multi gear ratios are not required for stupid acceleration if you throw enough power at it, even for heavy loads/big hills. This one will be single stage reduction, fixed sprocket on rear wheel with a freewheel sprocket on the motor shaft. Yuba frames are steel, so i will be MIGing custom support braces for the motor mount. ~3kWhr worth of Lipo will be going into the frame triangle and any left over space around the motor aft of the seat-tube.

phillistine said:
Fark you Boostjuice and your happiness and freedom and being a student. It must feel so empty and superficial getting sauced and plugging Canberra's young ladies. I get to stay home, cook a cake for my 2 year old's birthday tomorrow, clean the house, and then maybe, just maybe if I am lucky get half an hour of my saturday night out in the garage. Married with children is awesome I tells ya....
Click to expand...

:lol: I take it your wife doesnt know about all the kinky sodomy you were involved with in your 20's. Don't feel lacking, you've more than lived a little.
 
I take it your wife doesnt know about all the kinky sodomy you were involved with in your 20's. Don't feel lacking, you've more than lived a little.
Click to expand...

She is fully aware of what a reprobate I am, I think that attracted her in the beginning, but people change. That is the natural entropy of human relationships. Heck I can't complain, she married a fit toned guy, and now she has to look across the room at a paunchy wreck of a man with fraying mental health - no wonder I disgust her. I wouldn't sleep with me if I was a woman. That's not true, if I was a woman I would skeep with homeless men. Oh hang on, we aren't in the Biker Bar, I better get off this thread....
 
boostjuice said:
Heres a pic of the V4 without the electric kit (not the elMundo).

Yuba_Mundo_V4_4ddf4f378b2a3.jpg


And this may be what the V3.3 refers too.
Yuba_Mundo_V4____4de6d0b93811a.jpg
Click to expand...

Is it just me or do the rear dropouts look a little smaller in the 4.0 frame versus the 3.3?
 
What do you mean by smaller? Slot length/width/plate thickness, or the weight saving cutout on the V4? Apart from the cutout, dimensions look identical to me.

V3>V4(and probably V1>V2) all run 14mm wide slots for BMX axles. This accomodates the hybrid hub used which is 48spoke, disc brake flanged, 135mm O.L.D and accepting screw on 7spd freewheel clusters.
 
It must be the cutout on the forward portion of the dropout that makes it look smaller, like it doesn't extend quite as far forward on the stay as it does with the 3.3.

Thanks
Richard
 
I have just been wrestling in my garage with the V4 frame, and the drop outs. I personally think they are identical (to the images posted of the V3). I am almost certain they are identical.
 
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