Help rebalancing my bike collection

[atxmarmot]

I blame all of you in this forum for my descent into electric bike madness. So, here is the deal. I wanted an electric cargo bike for commuting and for carrying my kids to daycare. After much soul searching and some realistic evaluations of my available time for tinkering, I bought a radwagon ebike. This is a long tail cargo bike with a rear DD motor and overall I really like it. However, I was still intrigued by mid drive motors so I eventually bought a BBSHD kit and installed it on a 10 year old marin fairfax hybrid bike. The "problem" is I absolutely loved the mid-drive and I realized it really made a lot more sense on the frame of the radwagon. Plus, I live in the middle of a monster hill and the DD motor on the original radwagon does not have enough torque to get the fully loaded bike up the slope. Given this I decided to mount the BBSHD on the radwagon (today's project) and make some other arrangement for my pure commuter hybrid bike. In the meantime I became interested in internally geared hubs and found an old schwimm ebike with an 8 speed alfine and a front geared motor with a busted battery for a steal oncraigslist.
Why am I telling you all this? Well, since the information on this forum is what sent me down the rabbit hole, I was hoping for some help to identify and repurpose that front geared motor on my commuter. The motor is a front hub and it has the following code printed on the Outside: BF912D10028 and then 24V700C220W28KM. I assume this is a nominal 24V motor, but I know nothing else. The questions are:
1. Any information about this motor? A simple Google search did not lead me anywhere
2. Is it likely that I can run this off a 48Vbattery if I change the controller? Can somebody point me to an appropriate controller? I still have an "extra" 48V battery from my BBSHD kit, so I would like to reuse it if possible.
3. I think I know the answer to this,but is a front hub (low power) on a carbon fork a nogo? The marin has a carbon fork and ideally I would avoid changing it, But I don't want a nasty surprise either.

Thanks!

 

[dogman dan]

Personally,,I would never try any hub motor on carbon.. carbon frame, carbon fork, unless it was a metal plate bolted to the rear of a carbon frame.

Of course, there are forks and there are forks. Entirely possible to build a carbon fork plenty strong enough, but what you have is built entirely to be light.

The 24v motor will run on any voltage, just a matter of getting the right controller. But with any load, on the hills you likely have in your area, 48v will be a bad idea. Very likely to overheat on 48v, unless the load is kept under 200 pounds. That's you, the bike, the battery, the motor,, all under 200 pounds.

Run that thing on 36v more reasonable, but again, a 200 pound load limit for that size motor is a good plan. Load it up, lug it down on a hill, and it will get hot. Great candidate though, for a two motor bike. Your existing motor in back, the new one up front. Then the load carried by the small motor is much less.

BTW,,I bet the rad wagon will be better with the mid drive. But if you still need a bit more power, put that front motor on the rad wagon.

 

[Wolfeman]

I blame all of you in this forum for my descent into electric bike madness.

I feel the same way and love it! Great post atxmarmot.

 

[MrDude_1]

3. I think I know the answer to this,but is a front hub (low power) on a carbon fork a nogo? The marin has a carbon fork and ideally I would avoid changing it, But I don't want a nasty surprise either.
Thanks!

Can a carbon fiber fork be built to work with a hub motor? of course.
But no one makes one that way.

As you probably know, the axle puts some pretty strong pressure on a small area with a hub motor. When this happens while designing carbon fiber parts, the solution is often to use a metal insert. That way the force is spread over a larger area, and the CF can tie into it easily. Thats why you see all those cool CNC inserts inside all the high end car/plane/whatever parts where they bolt together. Most CF forks have an insert that is tiny, and just connects the fork tube to the wheel.. it not only cant take the torque and will spread, but also it has a good chance of pulling out from the rotational stress.

You probably also know that the entire point of carbon fiber bike parts is to be as light as possible. CF is layered thicker where it needs to be stronger, but is left thinner where it can be to save weight. Typically the fork does very little pushing/pulling and instead only has to hold the weight of the rider. Im sure you've seen the pics of when someone hits a curb or drops a wheel in a grate with a CF fork.

So... while there may be some overbuilt CF mountain bike fork that can take it with a torque arm... its unlikely thats what you have.

 

[atxmarmot]

Thanks all for the responses. Everybody agrees on the carbon fork not being a good candidate. I guess I knew that ... but was hoping someone had a magical suggestion that let me use it instead of going out and buying a steel fork for this.

OK, back to the more practical aspects of this ...

The 24v motor will run on any voltage, just a matter of getting the right controller. But with any load, on the hills you likely have in your area, 48v will be a bad idea. Very likely to overheat on 48v, unless the load is kept under 200 pounds. That's you, the bike, the battery, the motor,, all under 200 pounds.

Run that thing on 36v more reasonable, but again, a 200 pound load limit for that size motor is a good plan. Load it up, lug it down on a hill, and it will get hot. Great candidate though, for a two motor bike. Your existing motor in back, the new one up front. Then the load carried by the small motor is much less.

BTW,,I bet the rad wagon will be better with the mid drive. But if you still need a bit more power, put that front motor on the rad wagon.

I probably can just about hit that 200 pound mark so I am very tempted to use the motor on 48 V. I should clarify that the main hill is really just one steep but not very long hill and I would be helping substantially. The rest of the commute I hardly use the motor so I was hoping that this intermittent high load would not overheat it. Is this remotely reasonable? Also, any specific suggestions on a controller? This is an area that I know nothing about, but I am a reasonable handy electronics person, so I am not afraid of a soldering iron, etc.

I was hoping to keep the radwagon relatively simple and running two motors with 2 controllers, 2 batteries, etc seems more complexity than I care for at this point for this particular bike. Also, the front hub motor from the craigslist bike is laced into a 700c wheel and the radwagon uses 26'', so that would require even more rearranging :wink: On the other hand the original radwagon rear hub motor would make a good one for a mountain bike ... the problem being that I don't have a mountain bike ... again I am looking down a rabbit hole ...

 

[RyanC]

Man I can relate to this-

I bought a radwagon also for many of the same reasons...now I already have a 2nd dolphin and front motor for it coming from BMS and have started thinking about a gravel/hybrid/commuter.

One quick question- Did you try the 700C in the front fork of the RW? It might just fit depending on how big of a tire you have on there the OD of 700c isn't that much larger than the 26 with the larger balloon tires (I really like Big Ben Plus on the RW which are ~27.5 OD). Of course then you would loose the benefits of the balloon tire on the front...but it might be a cheap way to check it out.

On the other hand, I will be curious to follow your BBSHD on the RW. I'm leaning towards the 2 hub motors for less drive-train maintenance- but I haven't owned a mid-drive so have no real experience there. Anyway I'm really just posting to subscribe to your thread and see what tyou come with...

 

[atxmarmot]

Man I can relate to this-

I bought a radwagon also for many of the same reasons...now I already have a 2nd dolphin and front motor for it coming from BMS and have started thinking about a gravel/hybrid/commuter.

One quick question- Did you try the 700C in the front fork of the RW? It might just fit depending on how big of a tire you have on there the OD of 700c isn't that much larger than the 26 with the larger balloon tires (I really like Big Ben Plus on the RW which are ~27.5 OD). Of course then you would loose the benefits of the balloon tire on the front...but it might be a cheap way to check it out.

On the other hand, I will be curious to follow your BBSHD on the RW. I'm leaning towards the 2 hub motors for less drive-train maintenance- but I haven't owned a mid-drive so have no real experience there. Anyway I'm really just posting to subscribe to your thread and see what tyou come with...

No, I have not tried the 700c on the radwagon for a couple of reasons. The first is that I am not sure the wheel is sturdy enough for the use I want to give the radwagon. Also, the 700c wheel is for rim brakes and the radwagon uses disk, and finally, the added (or perceived!) complexity. I just don't want to deal with 2 motor setups. It seems too much trouble. I am following your thread as well I am very curious to know how your setup works out! And thanks for the tip on the tires as I will for sure need to get a rear wheel from somewhere. So much for making my life easier 8)

 

[E-geezer]

FWIW, a 700c wheel with @ a 3mm tire is the same as a 26" with a 2.2". I just converted a 26" mtb to road wheels for gravel/commuting, they fit fine. They all have to be discs obviously.

 

[dogman dan]

Yeah,, you can definitely push a tiny motor hard, if the use is more like you describe. When E Bikekit was selling a 350w motor, we got people melting them down, because they weighed 220 or so, then rode full throttle up and down hills for too long. So we started saying 36v only, and suggest a 200 pound weight limit. It will of course pull much more weight than 200 pounds if the use is not so continuous. So go ahead and run 48v. If you'd like to go a bit easier on it, put a 15 amps controller on it, rather than a 20 or 22 amps.


One thing about geared hub motors, once you heat soak one, it does take a long time to cool off, because the outer shell can cool while leaving the inner core where the motor is very hot. The core cannot touch the wind as you ride.

One thing working the chat at EBK has taught me,, until told different, assume all will weigh 230 or more, some much more, and none pedal much.

 

[atxmarmot]

Thanks for the reassurance and the tips! This small geared motor would go in my commute bike that is meant to "train" me to be a better cyclist, so I really don't use the motor much. With the BBSHD I would engage it for maybe a total of 5 minutes on a 30 minute commute, mostly for my initial hill (and the motor is totally cold at that point) and then for helping me power through a very busy intersection on a mostly flat section. DogmanDan, do you have a recommendation on a specific controller? Ideally I would love something that is compatible with the cycle analyst v3, as I want to look at some of the cool metrics and possibilities with that.

Yeah,, you can definitely push a tiny motor hard, if the use is more like you describe. When E Bikekit was selling a 350w motor, we got people melting them down, because they weighed 220 or so, then rode full throttle up and down hills for too long. So we started saying 36v only, and suggest a 200 pound weight limit. It will of course pull much more weight than 200 pounds if the use is not so continuous. So go ahead and run 48v. If you'd like to go a bit easier on it, put a 15 amps controller on it, rather than a 20 or 22 amps.


One thing about geared hub motors, once you heat soak one, it does take a long time to cool off, because the outer shell can cool while leaving the inner core where the motor is very hot. The core cannot touch the wind as you ride.

One thing working the chat at EBK has taught me,, until told different, assume all will weigh 230 or more, some much more, and none pedal much.

 

[MrDude_1]

Thanks for the reassurance and the tips! This small geared motor would go in my commute bike that is meant to "train" me to be a better cyclist, so I really don't use the motor much. With the BBSHD I would engage it for maybe a total of 5 minutes on a 30 minute commute, mostly for my initial hill (and the motor is totally cold at that point) and then for helping me power through a very busy intersection on a mostly flat section. DogmanDan, do you have a recommendation on a specific controller? Ideally I would love something that is compatible with the cycle analyst v3, as I want to look at some of the cool metrics and possibilities with that.

Yeah,, you can definitely push a tiny motor hard, if the use is more like you describe. When E Bikekit was selling a 350w motor, we got people melting them down, because they weighed 220 or so, then rode full throttle up and down hills for too long. So we started saying 36v only, and suggest a 200 pound weight limit. It will of course pull much more weight than 200 pounds if the use is not so continuous. So go ahead and run 48v. If you'd like to go a bit easier on it, put a 15 amps controller on it, rather than a 20 or 22 amps.


One thing about geared hub motors, once you heat soak one, it does take a long time to cool off, because the outer shell can cool while leaving the inner core where the motor is very hot. The core cannot touch the wind as you ride.

One thing working the chat at EBK has taught me,, until told different, assume all will weigh 230 or more, some much more, and none pedal much.

The coolest smallest controller right now is the Phaserunner... http://www.ebikes.ca/shop/ebike-parts/controllers/c-phaserunner.html# It will plug straight into your cycle analyst, let you do all the cool stuff.. but its 2.5 times (or more) the cost of other controllers.

Since you're looking at low power, you have tons of options. Do you care if the motor "rings" a little bit when you are using it, or do you want it silent?

 

[atxmarmot]

Hmmmm, that seems rather steep, although I do like how compact it is. I do care about ringing, I assume that you are asking because of square wave vs sine wave controllers. I am definitively willing to pay a little more for a smoother functioning controlled, but hopefully not quite that much. Ideally I would like this commuter bike to be as silent and stealth as possible. A question, are the controllers for DD motors and for geared motors different? I was wondering if I might be able to repurpose the controller from the radwagon to drive this.

Thanks for the reassurance and the tips! This small geared motor would go in my commute bike that is meant to "train" me to be a better cyclist, so I really don't use the motor much. With the BBSHD I would engage it for maybe a total of 5 minutes on a 30 minute commute, mostly for my initial hill (and the motor is totally cold at that point) and then for helping me power through a very busy intersection on a mostly flat section. DogmanDan, do you have a recommendation on a specific controller? Ideally I would love something that is compatible with the cycle analyst v3, as I want to look at some of the cool metrics and possibilities with that.

Yeah,, you can definitely push a tiny motor hard, if the use is more like you describe. When E Bikekit was selling a 350w motor, we got people melting them down, because they weighed 220 or so, then rode full throttle up and down hills for too long. So we started saying 36v only, and suggest a 200 pound weight limit. It will of course pull much more weight than 200 pounds if the use is not so continuous. So go ahead and run 48v. If you'd like to go a bit easier on it, put a 15 amps controller on it, rather than a 20 or 22 amps.


One thing about geared hub motors, once you heat soak one, it does take a long time to cool off, because the outer shell can cool while leaving the inner core where the motor is very hot. The core cannot touch the wind as you ride.

One thing working the chat at EBK has taught me,, until told different, assume all will weigh 230 or more, some much more, and none pedal much.

The coolest smallest controller right now is the Phaserunner... http://www.ebikes.ca/shop/ebike-parts/controllers/c-phaserunner.html# It will plug straight into your cycle analyst, let you do all the cool stuff.. but its 2.5 times (or more) the cost of other controllers.

Since you're looking at low power, you have tons of options. Do you care if the motor "rings" a little bit when you are using it, or do you want it silent?

 

[MrDude_1]

Hmmmm, that seems rather steep, although I do like how compact it is. I do care about ringing, I assume that you are asking because of square wave vs sine wave controllers. I am definitively willing to pay a little more for a smoother functioning controlled, but hopefully not quite that much. Ideally I would like this commuter bike to be as silent and stealth as possible. A question, are the controllers for DD motors and for geared motors different? I was wondering if I might be able to repurpose the controller from the radwagon to drive this.

You got it.. Square vs sine. The phaserunner is compact, silent, powerful but programmable.. so you can have it ramp in power and hold it while never exceeding a set amount of phase amps.. so the motor never sees more that what you tell it is the max. Cheaper controllers only watch the battery amperage. some of the newer sinewave cheap controllers do watch phase current. The phaserunner is a Field Oriented Controller (FOC). The three types are square wave, sine wave, and FOC.

The controllers dont know the diff between a DD motor and a geared one. They care about things like the number of stator teeth, magnets, etc... so some need to be programmed to work. I dont know if the radwagon uses a generic controller that you can setup, or if it is only for what it comes with.


The way I look at it, you have choices.
Very cheap chinese square wave. Cheap, will make noise, but will work without breaking for this application.
slightly more expensive sine wave. almost silent, not too expensive, will plug into your CA, but they all come in this clunky box.
phaserunner, silent, tiny, but you could buy 10 of the cheapest chinese square wave controllers for the price.


I think the 2nd one is your best option at the moment.

 

[atxmarmot]

The way I look at it, you have choices.
Very cheap chinese square wave. Cheap, will make noise, but will work without breaking for this application.
slightly more expensive sine wave. almost silent, not too expensive, will plug into your CA, but they all come in this clunky box.
phaserunner, silent, tiny, but you could buy 10 of the cheapest chinese square wave controllers for the price.

I think the 2nd one is your best option at the moment.

It is certainly looking that way. So no, onwards to find a reasonable sine wave controller and figure out how to hook it up!

On my radwagon front: I have mounted the BBSHD (very straightforward) and yesterday found a replacement wheel for the rear hub. I am keeping the 7 speed on the back so that I can reuse all the shifting hardware for the moment. I took it to a bike shop to do the change as I am not comfortable yet setting all the gear train. It will take them a few days, which is fine since I am waiting for an additional dolphin mount to be shipped. In the mean time, I am bike less, which is very sad

 

[MadRhino]

Mount the small hub motor as a mid drive on the cargo bike, and the BBS-x on the carbon bike. That is another solution. :wink:

 

[atxmarmot]

Mount the small hub motor as a mid drive on the cargo bike, and the BBS-x on the carbon bike. That is another solution. :wink:

That would be fun ... if I had more time to play with things ... and so much for simplifying my setups

 

[atxmarmot]

Thanks for all the feedback. Now some more detailed questions. As a reminder, I have a geared motor that used to run on an older Schwimm electric bike at 24 V. The old battery is dead; I want to transfer this motor to my commuter (a Marin Fairfax) and I want to reuse an extra (virtually unused 48V battery). For this I need a new controller which I am still undecided about. Eventually I would like to make a torque sensing setup with a cycle analyst v3. Would the following controller be a good choice? Any limitations to be aware of? Anything I might regret later?

http://www.ebikes.ca/shop/ebike-parts/controllers/c3620-gr.html

I am looking for something that is not crazy expensive and to reuse as many bits and pieces as possible.

Thanks!

 

[markz]

Anyone got any links on where to purchae Sinewave Controllers off ebay?

 

[LewTwo]

Anyone got any links on where to purchae Sinewave Controllers off ebay?

Search for "Brushless Sine Wave Controller". You should get several dozen hits from $40 to $140

 

[markz]

Anyone got any links on where to purchae Sinewave Controllers off ebay?

Search for "Brushless Sine Wave Controller". You should get several dozen hits from $40 to $140

Well if I pick a random one, I hope its decent.

 

[RyanC]

Did you get the BBSHD on the wagon up and running?

 

[atxmarmot]

Did you get the BBSHD on the wagon up and running?

Yes! I installed it last week and yesterday was the first true test on the road with cargo. I don't have pictures on hand but I will describe roughly what I did. I had a stock radwagon, which is a long tail cargo bike that comes with a read DD motor of 750W.

1. I took out the bottom bracket (easy with the right tool) and installed a 68mm version of the BBSHD. No problems or surprises there.
2. I used the stock Bafang chainring and this sits reasonably nicely in the #2 position for the shifter, so I didn't touch the front gears for now.
3. With the Bafang chainring the rear derailleur is able to shift through all 7 gears.
4. Since I did NOT want a dual motor bike, I needed to get a new back wheel. I wanted to keep as much of the original drivetrain as possible, so I had a bike shop change the whole thing over to a new wheel. It took them a while to get the right wheel, as they originally ordered a cassette and this uses a freewheel. In the future I might change the rear gearing altogether.
5. I ordered an additional dolphin mounting cage with bare wires and made a connector with XT90 plugs, so as to not destroy the original. My bottle battery (that I had bought together with the BBSHD) did NOT fit the frame of the radwagon, so I was reusing the dolphin battery that was originally there (48V).
6. I tool out the original throttle and substituted it by the bafang thumb throttle. I am still not quite happy with the handlebar setup, but I am not sure what I will do. Ideally I would have liked to keep the original throttle and connect it to the bafang, but I am not sure if it possible yet.
7. The motor inhibitors from the original brakes are not compatible with the ones in the BBSHD, so I probably need to change the brake levers. When I am near my bike again I will take some pictures and see if others have suggestions.
8. I have not yet installed the gear shifting sensor, or the speed sensor.

So, yesterday came the true test. I live in a hill with >20% slope. It is not super long, but enough that I could just about climb it with the original motor and one 2 year old on the back, no way I could handle the 2 kids with the original setup. This time I loaded both the 2 year old and the 4 year old and up the hill we went without issue! The bike is nicer to pedal now because of the freewheeling aspect. The original DD motor drag really bothered me. However, I might consider upgrading my brakes now that I don't have the regen to help me brake while going downhill. I still need to think that through.

 

[RyanC]

That's cool to hear that it's a relatively easy upgrade. I've thought about the BBSHD and some sort of IGH on my Radwagon. I'm learning ebikes and some bike mechanics as I go (and making mistakes along the way...) so this may be of little help, but on my Radwagon something was definitely wrong with the freewheel/axle/spacer/anti-rotation-washer setup. Not having any experience I chalked up the drag to the DD motor, but in order to have some higher gears I changed to a DNP 11-28 freewheel and it has way less drag. Before with no battery I would have to use the smallest chainring to ride it at all, maybe the middle one could be used downhill, and it had to be walked up any real climb. Now I can comfortably ride around on 2 and 3 without the battery, and even start from a dead stop on 3 and 1 without standing. It's a huge difference with the battery too.

Of course that could have just been my bike, or my lack of experience but digging deeper the way the motor and torque washer is setup on this bike seems a bit problematic. It might not matter with how they set it up with a new hub on yours, but it might be worth investigating if you are still using that stock freewheel.

Also I'm using one of these thumb throttles on my Radwagon and it works fine so I guess the reverse would also be true-

http://em3ev.com/store/index.php?route=product/product&path=50_55&product_id=199

It should be plug and play, the stock rad one also has that same orange 3 pin connector. I pluged it in and tried it with the wheel lifted before installing. I like the thumb one better, hated the on-off switch and b/c I put Ergon bolt on hand grips on there- comfy and much easier to get them on and off.

 

[atxmarmot]

That's cool to hear that it's a relatively easy upgrade. I've thought about the BBSHD and some sort of IGH on my Radwagon. I'm learning ebikes and some bike mechanics as I go (and making mistakes along the way...) so this may be of little help, but on my Radwagon something was definitely wrong with the freewheel/axle/spacer/anti-rotation-washer setup. Not having any experience I chalked up the drag to the DD motor, but in order to have some higher gears I changed to a DNP 11-28 freewheel and it has way less drag. Before with no battery I would have to use the smallest chainring to ride it at all, maybe the middle one could be used downhill, and it had to be walked up any real climb. Now I can comfortably ride around on 2 and 3 without the battery, and even start from a dead stop on 3 and 1 without standing. It's a huge difference with the battery too.

Of course that could have just been my bike, or my lack of experience but digging deeper the way the motor and torque washer is setup on this bike seems a bit problematic. It might not matter with how they set it up with a new hub on yours, but it might be worth investigating if you are still using that stock freewheel.

Also I'm using one of these thumb throttles on my Radwagon and it works fine so I guess the reverse would also be true-

http://em3ev.com/store/index.php?route=product/product&path=50_55&product_id=199

It should be plug and play, the stock rad one also has that same orange 3 pin connector. I pluged it in and tried it with the wheel lifted before installing. I like the thumb one better, hated the on-off switch and b/c I put Ergon bolt on hand grips on there- comfy and much easier to get them on and off.

That sounds way worse than mine. I could ride my bike on a flat with any gear combination. It is just that the drag from the motor was very noticeable and it bothered me because I like to ride without assist when I can, and of course there was the fact that I could not get up the hill with the 2 kiddos ... which was the original purpose for the bike. The BBSHD feels great in this bike and I think it is going to make for a very worthy improvement. Of course I am aware that it will impose more wear on the drive train, but only time will tell how that plays out. I am not one to be gunning the setup, so my hope is that it is sturdy enough. I still need to refine the whole setup but I am liking it a lot. In the future I might consider an IGH as well. In fact I bought a second hand bike just because it had an alfine 8, but for the moment that piece of kit is going into my commuter setup, not the cargo bike

Let us know what mods you make to the bike. The tip about the improved freewheel is definitively something useful for radwagon owners.

 

[RyanC]

Let us know what mods you make to the bike. The tip about the improved freewheel is definitively something useful for radwagon owners.

Yeah I'm much happier with the 11t smallest cog. Especially after setting the top speed to 40km/hr, no hamster wheeling at all and it actually feels like the PAS modes make more sense. I have the 2wd radwagon thread started, am just collecting all the parts now but I'll post some pics there as I get into it. One thing I added was a dropper/suspension post that is pretty cool. It takes the edge off and for commuting the dropper is actually great for sitting at red lights (lol). I don't have room for a 2nd bike or I might be doing a separate commuter as well.