Overwhelmed: Advice on Mundo + mid-drive combination

[atxmarmot]

New to the forum and mostly to bikes and particularly to e-bikes. I apologize in advance for not calling things by their proper name ... very much still learning. So, here is the situation. I live on a *very* steep hill. This is the hill where people in my city come to train and many give up right around where my house sits. I am in somewhat reasonable shape, but I am not a bike person (yet!), but want to start commuting by bike and take my 2 kids around. For hauling the kids I need a cargo bike, and to get up the hills in my area I need an assist or I will never actually take the bike out. After some research here, I think a mid drive motor makes sense for a high load + steep hills situation like mine, and the bafang kits seem popular. Looking around for cargo bikes, I like the Yuba Mundo bikes and they seems not too outrageously priced. My commute will be around 6 miles each way with a couple of serious hills. I am not looking for speed, but rather the ability to haul a loaded cargo bike up the hills and across intersections without issue.

So, can you guys help me clarify a few things before I start ordering?

1. Does a Mundo (v4 or v5) + Bafang mid-drive kit seem like a good combination, any objections? Which Bafang kit, 500, 750, 1000? It seems like powerwise any of them would work for me but the HD has ironed out some issues with the previous versions. Is that enough to choose it rather than some of the older ones?
2. From my understanding the Bafang assist is based on cadence rather than torque, is it easy to modify this to work based on torque? I could not quite follow the discussion regarding this ... Also, will hydraulic disc brakes be a problem?
3. I am a bit at a loss as to whether the mid-drive motors make the original gearing of the bike unimportant or not (at least the part near the motor). One of the differences between the v4 and v5 of the mundo is the gearing so it would be good to know if that is a moot point after installing the motor kit.
4. Thoughts about use of IGHs? I seem to have read conflicting reports.
5. Finally, a very subjective question. Is this install horribly complicated? As I mentioned I am not a bike person but I am fairly handy both with electronics and mechanical stuff but I don't want to get completely over my head.

Anything else I should be looking into? Sorry to launch such a bunch of basic questions, but after reading non-stop for a week I could really use some hand-holding

Thanks!

 

[dogman dan]

I can't answer most of your questions, but I'll try on a few.

1. Yes, the Mundo and a mid drive is an awesome combination. I rode one at interbike and found even the 350w mid drives climbed a very steep hill with ease, and no hard pedaling. I'd say that 750w version should be adequate, since you can use the motor power in a very low gear. 750w is like having a pro sprinter helping you ride. With the mid drive, it really is a lot.

2. Hydraulic discs will not be a big problem, especially if you ditch the idea of PAS. But since typical cadence based PAS means you get less perfect control of the motor, you WILL need to install brake cutoff switches on your hydros. Not part of the regular kit, but possible to do. But easily solved several ways, such as using a tolerably good cable disc brake caliper. Then you can use the cable type brake switches, that cut the motor anytime you grab a brake.

But to my mind, since I really do loathe cadence based PAS, the best solution is just equip your bafang with a throttle. Then you really don't need brake cutoffs, and can use the hydros with no complications. I have not ridden torque based PAS myself, but know it's LOTS better. But even with torque based PAS, I'd want the brake switches. It should be possible to put torque based pas on the bafang, but I think it's not going to be a simple plug and play mod, unless the Bafang now comes with a Cycleanalyst plug now. Maybe it does? Hard to keep up sometimes.

3. The gears are not unimportant. But with 750w of mid drive power at your fingertips, you really won't need that tiny front chain ring. Even with much less efficient hub motors, you rarely use the gears below the middle ratios. You just won't really need them.

4. IGH? I'd say for a cargo bike, heavily loaded, you'd want to stick with the much stronger, harder to break chain and derailleur.

5. The install? I really don't know. It will be harder than a hub motor. But it should not be impossible at all for you, once you obtain the tool you need, if you have basic mechanical skills. If you do get over your head there is an ES member in your town, who is a pro bike mechanic. Chalo is his ES name.

 

[teklektik]

As cargo bikes go, the steel Mundo is a good deal: pretty good quality components and a frame that is reported as rigid and having negligible flex in virtually every review. I have over 11000 mi on mine and regularly run it 35mph. It has no noticeable flex and very steady at 40mph (not really recommended, but it does it just fine). The newer (optional) CroMo frames are almost certainly of thinner tube construction and may ride slightly differently, although the large oval top and down tubes, 6-stay welded luggage rack and CroMo sideloaders give a fair bit of structural strength regardless of material. I mention this since you will no doubt also be going down those hills that you are concerned about climbing...

On the downside, the Mundo has 14mm dropouts in the rear that are slightly problematic if you change out the stock 48 spoke rear wheel. There are a number of ways to address this (see my build and others by Kiwi - his torque plates are an option). Since you are looking mid-drive instead of rear hub motor, there is no intrinsic need to swap out the rear wheel, so not an issue...

Another slightly weird thing about the Mundo is the rear disc brake mount which is non-standard making use of certain calipers/rotor sizes a bit of an adventure - the standard adapters don't fit since the mount has a built-in cant for a 160mm disk. I run Avid BB7's and a 185 mounts up with only minor finagling in the rear (again - see build thread). I see that the newer Mundos all come with Tektro disc brakes (used to be an option), so this is also likely a non-issue unless you swap brakes.

The Mundo fork and seat/chain stays will allow oversize tires to get a bit of a better ride. I run 26x2.35 Big Bens and they fit without difficulty but are nearly as big as you can go in the rear without messing with the cogs/chainline.

The Bafang drive solutions certainly get a lot of play, but it's worth noting that since you have a cargo bike with a stretched frame, the knee-jerk canned solution meant for a conventional frame may not take full advantage of your unique situation. You might like to take a look at the Stoke Monkey solution that is a more mature and arguably more robust design - The 'Cycle Stoker' kit is a one-stop kit specifically designed for the Mundo if you prefer that over the generic mount. These are both more expensive than the Bafang approach, but they are mechanically simple, can use any controller, etc...

I use a CA V3 to supply PAS. The CA is not Bafang-friendly in this regard since that unit has its own PAS mechanism, however, for the Stoke Monkey it works out well. You can configure a number of different types of operation including fixed or rpm-based assist using a simple PAS wheel. The CA can set PAS levels using an optional external control (switch, pot, etc), but I would recommend a pot so you have infinitely adjustable assist. I frankly added PAS to my bike on a lark being a long time motorcyclist, but was quite captivated by the experience and use it all the time. Unlike some of the cheap PAS units, the CA allows you to adjust for smooth getaways and variable assist levels (instead of fixed steps). Of course, if you run any PAS system you will need ebrakes to ensure the power goes off smartly without overrun when you stop pedaling and apply brakes. Hydraulics make this a little challenging , but as an alternative using conventional ebrake switching, for me the 185 BB7s have good feel and can break the tires free - which is the limit of stopping power anyway. Torque sensing is pretty much off the table for the SM and Mundo combination.

So - 'yes' for the Mundo and take a look at the SM/CA as another option.

 

[Drunkskunk]

Welcome to the forum.

Do you live in or near the Jester Estates area in Austin? Off 360 and 2222? If so, I know those hills. They are beyond what most ebikes could do, so I would only consider the BBSHD 1000W motor of those you listed. teklektik's recommendation would be a better idea, but more complicated to install and maintain.

The mid drive still need the original rear gearing. It is still important. the front gearing is replaced when using the Bafang system. You will still need low gear for climbing, and high gear for speed, though you won't have to shift as often.
IGH are great, with a few drawbacks. The first is a loss of around 10% efficiency. The second is the fact that even the stoutest, most bullet proof of them is still weaker than a conventional exposed gear and derailleur design. I wouldn't give up an IGH, but I wouldn't switch to one for a hill climber, either. Use what the bike has, and you should be fine.

PAS, pedal assist, sounds like a great idea to many. And to be fair, some people actually do end up liking it. But for hill climbing, You may prefer a throttle.
The main difference between a throttle based ebike and a PAS, is that with the throttle you have instant power, and continuously variable levels of assist. you can add or remove any level of assist as you pedal depending on the needs. Big dog chasing you? Throttle up and GO! Light turning yellow? put the power on and make it! Hill much easier to go up than you thought? Throttle back and feel the calories burn!
PAS, however, locks you into a preset level of assist. you can change the options and increase or decrease the assist, but it's neither instant, nor intuitive. This is great if you want a consistent, repeatable workout and don't have the discipline to hold constant throttle. But that is about it's only advantage.

 

[atxmarmot]

Thanks dogman dan, tekletik and drunkskunk. That is exactly the kind of information I was looking for. I still have some questions but things are making more sense.

From what you guys have said and some further research. This is my current thinking.

1. Stay with the v4 of the Mundo with the stock disk brakes. There does not appear to be much advantage to going with the newer chromealloy frame in the v5 for my use.
2. I am going to forget about IGHs for now. I'll stick with whatever is mounted as stock.
3. Seems like torque based PAS might be something to leave for a later upgrade. Currently I am thinking of using a throttle and maybe reconsider PAS at a later date, perhaps when I have a better idea of my needs and what I feel like I am missing. What are the thoughts regarding throttle vs thumb activated and left vs right. I am comfortable on a motorcycle but on the other hand a left activated thumb switch seems like a good way to mount things regarding distribution on the handlebar and brake activation. Ay thoughts?
4. I looked at the SM rear hub solution suggested by tekletik. It seems like a nice kit but between the price difference and the fact that a mid-drive seems to make more sense I think I am still leaning towards the bafang. Are there other suggestions for appropriate kits?
5. drunkskunk nailed it, indeed I live not too far from Jester states in West Austin So, I am kind of thinking a BBSHD given the extra power and it is newer so I expect some kinks have been ironed out.
6. Regarding the gearing. You clarified that if I install a mid-drive I would have to get rid of the front gearing. I was hoping I could keep the original gearing of the bike intact, but I guess it is a reasonable compromise.
7. With a throttle, how does one change gears? Does one need to touch one of the brakes that is rigged so that it disconnects the motor?

Thanks again for your help and I will make sure to look at some of the builds and options that tekletik was mentioning.

 

[teklektik]

4. I looked at the SM rear hub solution .... It seems like a nice kit but between the price difference and the fact that a mid-drive seems to make more sense...

The SM is a mid-drive - not a rear hub. It drives through the chain as does the Bafang...
No problem if it's not for you, but you need to slow down and study this stuff a little more carefully.

 

[atxmarmot]

And this proves exactly why I need help! I somehow thought it was a rear hub motor. I will look at it in more detail. I am in no way set on the bafang, I just need to make an informed choice and I am not there yet I will do more homework!

4. I looked at the SM rear hub solution .... It seems like a nice kit but between the price difference and the fact that a mid-drive seems to make more sense...

The SM is a mid-drive - not a rear hub. It drives through the chain as does the Bafang...
No problem if it's not for you, but you need to slow down and study this stuff a little more carefully.

 

[cwah]

What about cyclone?

 

[atxmarmot]

Okay, so I am looking at the SM kit for the Mundo and it does look pretty nice. I am not sure why I thought it was a rear hub... Mushy brain, I guess. It is a bit more than I was hoping to spend but it is definitively worth a careful look. So, the kit says it includes the ca3, which I suppose is the controller. So, would this allow for a pedal assist configuration based on torque? Can one have a torque based pedal assist combined with a throttle for when you just want to press and go? Also, if I was to build based on this kit, what else would I need? A battery is one thing of course, but anything else?

Thanks for all the answers. I am trying to read as much as possible in the forum, but it is a lot of scattered information!

 

[Lurkin]

Welcome, welcome.

As it sounded like you had been taken by the BBSHD, I would start by reading the wiki. It contains a summary of all the mid drives which were available at the time of writing with their description varying on the authors knowledge. You should really read through it and slow down a bit. It's hard because its exciting, but more time spent now will result in being more content later. Here: https://endless-sphere.com/w/index.php/EBike_Motors_Middrive

I have updated the Bafang section in the last six months, unfortunately, it does not specifically contain too much information about BBSHD/ needs a little updating about BB sizing as Bafang have made changes since I finished writing it. In any case, it will give you an idea about the installation, the tools, the potential problems etc. Great starting point. Again, most of these were detected based on the older BBS01/2 series, but should still remain as a crash course. Up to date BB sizing can be obtained directly from Bafangs website, here: http://www.szbaf.com/en/components/motor.html

WIth regard to hydraulic brakes:
The Bafang loom has female adapters for a reed or hall sensor to be plugged into. The vendor you purchase from will determine what type of sensor they sell with their kits. This is usually a hall sensor imbedded in a set of ebike brake handles. These handles usually are suitable for cable operated brakes and both look, and are, low quality for the price sensitive. These are the usual default option and in the absence of any other option, they can be gutted for their hall sensors and used as the next option described. Its not ideal because the resulting bare hall sensor will be ugly and not waterproof.

Alternatively, most vendors also have a different offering of sensor to be unceremoniously cable tied, taped and/or glued to your existing hydraulic brake levers. Sometimes they will offer to swap the brake levers for hydraulic sensors - this is the cheapest option. Beware that some vendors will attempt to swap a pair of levers for one hydraulic sensor. Due to their higher price at cost, they want to get out of swapping two for two. If they won't yield and you want two sensors, you will need to purchase a second. Note the kit will work with just one, and the other socket empty. However, if you grab the unsensored brake, the motor will continue to propel against the brake, potentially pushing you into traffic.... get two.

Torque sensing/PAS/CA control
As for torque sensing, I haven't seen anyone convert one as they are not set up for it out of the box. Further, given the large number of magnetic poles the cadence sensing is usually fine for most. Its more seen as a nice to have, you'll be the pioneer of it I think. Kepler has previously made a custom loom for his BBS02 to allow the use of a CAv3, which if used, could be used with a torque sensor. You will need to factor in another ~USD120 for the CA and more for your time and the torque sensor.

The nice parts of this kit include pretty much everything to install it other than the battery.

Cant comment on the SM kit, haven't had one to play with. 8)

 

[amberwolf]

Okay, so I am looking at the SM kit for the Mundo and it does look pretty nice. I am not sure why I thought it was a rear hub...

Probably because it *is* a hub, just with it's spoke flanges stripped off and mounted in a bracket for mounting to the bike frame.

So, the kit says it includes the ca3, which I suppose is the controller.

Not exactly; it's more like a monitoring/master unit that can interpret your throttle, brake, and other inputs, and the power from the battery, etc., and send modified or unmodified versions of thsoe signals to the actual motor controller, to make it run the bike the way you want it to.

So, would this allow for a pedal assist configuration based on torque? Can one have a torque based pedal assist combined with a throttle for when you just want to press and go?

As long as it already has the torque-sensing BB capability, then yes, you could use throttle and/or torque-pedal control.

BUT: since the StokeMonkey's motor output goes thru the entire BB (coming in from the left side and going out the right, just like your own pedal input), I don't know if you can use any kind of pedal torque control with it, since the motor would also trigger itself, once you start it going with throttle or pedals it would then make the sensor think you were pedalling, too, and it would never stop.

You'd have to check the Stokemonkey specs to see if they've changed where it sends power into the system, to know if it is possible or not.

If the SM was setup to drive the wheel on it's *left* side, not going thru your regular drivetrain at all, then it'd be easy to use either throttle or torque-pedal control.

FWIW, this is the same problem that ALL middrives that put power thru the crankshaft(BB) will have.

If the middrive doesn't drive the actual BB, then that's different, and could work...but those like the BBSxx types probably can't have a torque-sensing BB installed, because they have their own custom BB as part of them already. There may be alternative ways to sense the torque on the cranks themselves that you could use, but they may require more interfacing or control electronics to be made for them.

Also, if I was to build based on this kit, what else would I need? A battery is one thing of course, but anything else?

Probably just the battery, but you'd have to see what requirements it has other than that, from it's vendor or manufacturer page.

I am trying to read as much as possible in the forum, but it is a lot of scattered information!

Yes, it does. :/ A lot of people have tried to work to get it into the wiki, but it is a lot of work and time, and it's a never-ending job.

 

[John in CR]

What goes up must also go down, and if the hill is truly steep then going down will be the scary and dangerous part. Borrow or rent a bike first and check it out on your hill. Without strong regen brake maintenance will be frequent, and I'm just not one to fiddle with routine maintenance. To me that leaves 2 options, because I prize quiet operation (who wants to ride a blender?):
1. 2wd using direct drive hubmotors in small wheels. Small wheels are the only way to gear them down.
2. Use one DD hubbie running out of the wheel connected directly to the rear by a belt or chain gear reduction with no freewheel.

Both options would be a workout for pedal only operation, but you're not a cyclist so I figure dependability and low maintenance are higher priorities.

 

[dogman dan]

Nothing wrong with the stoke monkey kit idea either. Brakes, as said above, will need to be very good. So leaving the stock hydros alone sounds like a good plan.

Again, if you just go throttle, then you don't need the e brake cutoff switches at all, and you just let go of the throttle when braking. That approach has worked fine for a century or so, on motorcycles. You could add the switch to hydros, but with a throttle it's a choice, not mandatory.

On the other hand, regen braking does work nice. One of the advantages of a hub motor. But to make a hubbie work on those hills you need a different bike. Something with 20" rear wheel, like the ODK or the edgerunner. And, you'd need a big motor. One with more power than legal in Texas.

 

[atxmarmot]

Lots of good information in the responses:

If the middrive doesn't drive the actual BB, then that's different, and could work...but those like the BBSxx types probably can't have a torque-sensing BB installed, because they have their own custom BB as part of them already. There may be alternative ways to sense the torque on the cranks themselves that you could use, but they may require more interfacing or control electronics to be made for them.

Okay, I get it now. With the usual mid-drive kits it is not clear where to set a torque sensor so that your input and the motor input are not mixed up. I think this makes it clear to me that I am not going to do a torque sensor in a mid-drive in the short term.

WIth regard to hydraulic brakes:
The Bafang loom has female adapters for a reed or hall sensor to be plugged into. The vendor you purchase from will determine what type of sensor they sell with their kits. This is usually a hall sensor imbedded in a set of ebike brake handles. These handles usually are suitable for cable operated brakes and both look, and are, low quality for the price sensitive. These are the usual default option and in the absence of any other option, they can be gutted for their hall sensors and used as the next option described. Its not ideal because the resulting bare hall sensor will be ugly and not waterproof.

So, I should make sure I have good brakes and it seems like hydraulic won't be an issue. There are several options for linking the brakes to a motor disconnect.

So, the kit says it includes the ca3, which I suppose is the controller.

Not exactly; it's more like a monitoring/master unit that can interpret your throttle, brake, and other inputs, and the power from the battery, etc., and send modified or unmodified versions of thsoe signals to the actual motor controller, to make it run the bike the way you want it to.

Yeah, again got things mixed up, I figured after reading a bit further that I was lumping together the controller and the extra electronics that interface to the controller. Thanks for clarifying. BTW, that CA3 looks like an extremely nice addition. Too bad it seems very hard (impossible?) to interface with the bafang motors.

What goes up must also go down, and if the hill is truly steep then going down will be the scary and dangerous part. Borrow or rent a bike first and check it out on your hill. Without strong regen brake maintenance will be frequent, and I'm just not one to fiddle with routine maintenance. To me that leaves 2 options, because I prize quiet operation (who wants to ride a blender?):
1. 2wd using direct drive hubmotors in small wheels. Small wheels are the only way to gear them down.
2. Use one DD hubbie running out of the wheel connected directly to the rear by a belt or chain gear reduction with no freewheel.

Both options would be a workout for pedal only operation, but you're not a cyclist so I figure dependability and low maintenance are higher priorities.

Well, I don't mind doing some regular maintenance on my brakes, but definitively dependability is high on my priority list. I'll have to think about the options here.

What about cyclone?

I still having looked at those kits in detail, it is on the list of things to check out. I am getting confused enough trying to sort out options between Bafang and StokeMonkey at the minute.

Right now, assuming I was deciding only between a Bafang 1000W and a Stoke Monkey for a Yuba Mundo I would find it difficult to make a decision. It seems like the control electronics are nicer in the SM, but there is a considerable price difference. Assuming I would set up the bike with a throttle and cadence based pedal assist, with hydraulic brakes with a motor disconnect, is there a compelling reason to go for the Stoke Monkey?

Thanks!

 

[Drunkskunk]

.....is there a compelling reason to go for the Stoke Monkey?

Yes. Eventually. The SM will be more robust, and more tailorable to your needs. If you find it doesn't meet your needs, it's much easier to make changes to the SM system so that it does meet your needs.
It's also a whole lot more challenging to install, and will need more maintenance. It isn't a simple bolt on process, you may need to modify or fabricate parts to make it work to your satisfaction. The drive chain is exposed, and will need some form of protection fabricated if you will have kids dangling their legs around it. The Control system is open ended and can be tailored to your needs, but isn't exactly plug-n-play, etc, etc, etc.

Of the two, the Bafang makes the better first kit. The Stoke Monkey makes a better Ebike.
Very few forum members here have built only one Ebike. So my advice is to build an easy one first, Like the Bafang, then build something complicated after you have a lot more experience.

 

[WoodlandHills]

Thanks dogman dan, tekletik and drunkskunk. That is exactly the kind of information I was looking for. I still have some questions but things are making more sense.

From what you guys have said and some further research. This is my current thinking.

1. Stay with the v4 of the Mundo with the stock disk brakes. There does not appear to be much advantage to going with the newer chromealloy frame in the v5 for my use.
2. I am going to forget about IGHs for now. I'll stick with whatever is mounted as stock.
3. Seems like torque based PAS might be something to leave for a later upgrade. Currently I am thinking of using a throttle and maybe reconsider PAS at a later date, perhaps when I have a better idea of my needs and what I feel like I am missing. What are the thoughts regarding throttle vs thumb activated and left vs right. I am comfortable on a motorcycle but on the other hand a left activated thumb switch seems like a good way to mount things regarding distribution on the handlebar and brake activation. Ay thoughts?
4. I looked at the SM rear hub solution suggested by tekletik. It seems like a nice kit but between the price difference and the fact that a mid-drive seems to make more sense I think I am still leaning towards the bafang. Are there other suggestions for appropriate kits?
5. drunkskunk nailed it, indeed I live not too far from Jester states in West Austin So, I am kind of thinking a BBSHD given the extra power and it is newer so I expect some kinks have been ironed out.
6. Regarding the gearing. You clarified that if I install a mid-drive I would have to get rid of the front gearing. I was hoping I could keep the original gearing of the bike intact, but I guess it is a reasonable compromise.
7. With a throttle, how does one change gears? Does one need to touch one of the brakes that is rigged so that it disconnects the motor?

Thanks again for your help and I will make sure to look at some of the builds and options that tekletik was mentioning.

3. If you buy a BBSHD you will get the PAS, why not use it? There is a lot of misunderstanding about the Bafang system. The first being that it is not a pedal assist system at all, but is instead a cruise control/throttle lock that uses pedal movement as an on-off switch. It does not count cadence. It does not sense rider input. It only knows if the pedals are turning, if so, it turns on the motor. There are 9 power (PAS) settings available and they will give 9 different speeds in each gear, if your display has less than 9 settings your lowest setting is #1 and your highest is #9, the others settings are either #3,5 and 7 (for a 5 level display) or #5 (for a 3 level display). There is a maximum speed and % of total power associated with each PAS setting which is accessible via a programming cable and a PC. The displays also have two levels of settings menus where you can change the number PAS levels, however not every display can be set to all numbers of PAS levels.

If you have more miles using motorcycle hand controls as opposed to bicycle controls it might be wise to stick with that setup. In a panic/emergency situation muscle memory will take over and you don't want any confusion..... I started out with a thumb throttle, tried it on both side of the handlebars, and wound up installing a twist grip on the right side. Just like all my motorcycles.

I also find that on rides of over an hour or so, twisting the throttle cramps up my right wrist. I always had throttle locks on my tourers and sport bikes for freeway drones and the same applies to powered bicycles. The PAS does just that on a Bafang, you have to move your feet to turn it on, but then you can let go the throttle and cruise for hours. I did 2.5hrs each of the last two days that way with no discomfort. I have the three button switch from the display mounted where I can easily adjust it on-the-fly and I adjust it as the terrain changes and as I change gear to maintain a constant speed. For me it's easier than holding a throttle for hours: I like long rides.....


6. Gearing is everything, just like any other bicycle. You have more power than a single human, but you don't have THAT much! Correctly geared, a loaded cargo bike should be able to climb most any hill on motor alone. Just remember that you are building a truck, not a car and definately not a sports car, and gear accordingly. The market is responding to demand and is beginning to supply a selection of chainwheels to help you do just that.


7. To interrupt power and prevent crunching your gears, backpedal a fraction of an inch and the drive shuts off at once. Start to pedal again without waiting to shift: there is a short delay built into the resumption of power when forward pedal movement is sensed. This delay is plenty of time to make your shift before the Bafang starts up again, at least it is enough for my IGH I assume a deraileur is just as fast. The instant of backpedaling is your clutch.......

 

[amberwolf]

6. Regarding the gearing. You clarified that if I install a mid-drive I would have to get rid of the front gearing. I was hoping I could keep the original gearing of the bike intact, but I guess it is a reasonable compromise.

The SM kit drives the left side of the cranks, so it leaves your gearing completely intact.

That is probably your best reason to get that one for your purposes.

 

[atxmarmot]

These two statements are making me lean towards the Bafang again:

6. Regarding the gearing. You clarified that if I install a mid-drive I would have to get rid of the front gearing. I was hoping I could keep the original gearing of the bike intact, but I guess it is a reasonable compromise.

The SM kit drives the left side of the cranks, so it leaves your gearing completely intact.

That is probably your best reason to get that one for your purposes.

The SM will be more robust, and more tailorable to your needs. If you find it doesn't meet your needs, it's much easier to make changes to the SM system so that it does meet your needs.
It's also a whole lot more challenging to install, and will need more maintenance. It isn't a simple bolt on process, you may need to modify or fabricate parts to make it work to your satisfaction. The drive chain is exposed, and will need some form of protection fabricated if you will have kids dangling their legs around it. The Control system is open ended and can be tailored to your needs, but isn't exactly plug-n-play, etc, etc, etc.

Of the two, the Bafang makes the better first kit. The Stoke Monkey makes a better Ebike.
Very few forum members here have built only one Ebike. So my advice is to build an easy one first, Like the Bafang, then build something complicated after you have a lot more experience.

Man, I thought this was going to be a nice little project to put together for my big birthday, but it sure is looking complicated ... and I am only in the research stage!

So, it looks like I can get a Bafang BBSHD kit and battery from Lunacycles, as it seems a reputable supplier. Are there other places people would recommend from personal experience? I am a bit wary of ordering directly from China given my level of experience and the fact that Chinese New Year is around the corner and that stops pretty much everything in the country.

 

[Lurkin]

Here: https://endless-sphere.com/forums/viewtopic.php?f=4&t=60790

I have had good results with Paul of Em3ev. After by BBS01 died after ~3,500kms, it was sent back to Bafang in china for repair and returned to me, covered by Em3ev including freight. Top bloke, recommended.

I would be personally trying to find someone closer given its your first build and shipping a BBSHD around is going to be expensive due to its weight if something goes wrong. Further, battery freight seems to be becoming relatively extortionate, so getting that nearby could also be win.

 

[tomjasz]

So, it looks like I can get a Bafang BBSHD kit and battery from Lunacycles, as it seems a reputable supplier. Are there other places people would recommend from personal experience? I am a bit wary of ordering directly from China given my level of experience and the fact that Chinese New Year is around the corner and that stops pretty much everything in the country.

Luna offers the same coverage and is in the USA. California eBikes is also a valued dealer. Higher prices but you're dealing with EM3ev USA repair station with Doug at Cali eBikes. EM3ev batteries too. Doug at Cali is not affected by the holiday

 

[lowbudget]

Why not the "cycle stoker" from Grin? It has everythinv you need, including torque sensing, is made for your bike, and comes from the most trusted, and respected company. It is more expensive, but by the time you build something equivalent, not so much, if at all. I run a similar set up, though Self constructed, and it works beautifully. I don,t see anything as complete, or high quality, not to mention the level of customer service that grin provides. Just sayin

 

[teklektik]

This option was mentioned very early in the thread...
The 'Cycle Stoker for Mundo' is not the same product as the 'Stoke Monkey'. The Stoke Monkey can be purchased with clamps sized for the Mundo and is pretty much a bolt-on affair, but it follows the classic design with left hand drive and no torque sensing. The Cycle Stoker is a complete plug and play bolt up solution with custom machined Mundo mounting plate containing a unique Grin Tech non-BB torque sensor and uses the rider's chain for right hand drive. It's priced higher than the SM.

 

[alsfries]

OP- what did you end up with? I'm starting the process of adding a conversion to my Mundo v4 and am leaning towards the Bafang BBSHD 1000w and would love to hear what you ended up with and any learning/ tips.

 

[Voltron]

The Mundo is a great platform for conversion no matter what system you end up with. And you might have thought the Stoke Monkey was a rear hub is because it uses what is normally a hub motor for the back, mounted in brackets in the frame, which is what John in CR meant by running a hub motor out of the wheel. The frame gives you so many options of motor and battery placement.... it makes you want to get two do you can compare them.



The one has a temporary front motor...until I get this installed.


Whatever you end up with...it will be a great workhorse.