Mid drive kit on Babboe City cargo bike?

jsl · Aug 7, 2018

Hi everyone - new to forum. Just picked up a used Babboe City cargo bike. Love it, though it's a struggle going up hills when I'm carrying a load. Really looking to add a mid-drive unit to it, but looking for advice on the build in terms of what works for a motor. Also looking a for a build that can be installed without too much alterations to the bike and can be removed if needed if I need to re-sell the bike. Not looking for crazy speed, just enough pedal assist with hills & when I'm carrying a load.

NYC based.

I've looked at bit at the Bafang BBSHD motor, and recently learned about the TongSheng TSDZ2.

* I suspect the bottom bracket is 68mm, however, it looks like there's a "spine" along the cross-tube all the way to the bottom bracket -- is this going to get in the way of a mid-drive?
* Specs mention the bottom bracket is Shimano Cartridge Sealed https://www.fourthfloordistribution.com/products/city
* The chainring is a 33T, and there's a 7 speed Shimano Nexus IGH in the rear wheel (also has a full chain guard, that I would love to keep if at all possible)
* Existing crank arms are 170mm.
* Brakes are Shimano IM-40 Roller Brakes (hoping to not have to upgrade these if possible?).

Any and all suggestions & pointers welcome. I've looked for other builds but haven't found a similar one yet.

Thanks!

amberwolf · Aug 7, 2018

You may have to measure the spine and tubes and whatnot, and compare them to spacings either in the middrive specs, or in pics of middrives others have mounted where you can see those spacings.

Otehrwise the only sure way to know if it will fit is to try it. Sometimes you can modify the drive casings a little, to clear stuff on a frame; depends on what, where, and how much.

I suspect you may have to modify the chain guard to clear the middrive mechanisms; sometimes the chainline is changed by these drives, too.

Since you're in NYC, you may want to check out whatever the latest ebike laws are, since they seem to like to crack down on anyone not obeying them, and take their bikes away, based on other discussions here on ES at least.

I wouldn't want you to lose your transportation.

jsl · Aug 7, 2018

Thanks for the response!

Yes, it looks like I may not be able to use the BBSHD without grinding away the spine or modification to the housing (since it gets rotated foward on the BB away from from the chainstays [?]).

I haven't been able to find the specs or any good pictures of the TSDZ2 to see if this works. It does look like it has a bracket / mounting between the chainstays to rotate it backwards [?]

Looks like NYC has gotten a little more lenient on ebikes recently - see https://www.citylab.com/transportation/2018/04/new-york-city-makes-space-for-e-bikes/557396/

amberwolf said:
You may have to measure the spine and tubes and whatnot, and compare them to spacings either in the middrive specs, or in pics of middrives others have mounted where you can see those spacings.

Otehrwise the only sure way to know if it will fit is to try it. Sometimes you can modify the drive casings a little, to clear stuff on a frame; depends on what, where, and how much.

Since you're in NYC, you may want to check out whatever the latest ebike laws are, since they seem to like to crack down on anyone not obeying them, and take their bikes away, based on other discussions here on ES at least.

I wouldn't want you to lose your transportation.

2old · Aug 7, 2018

As long as you're not dealing with steep hills or slippery terrain, your situation may be tailor-made for a front hub installation. The only drawback that I can perceive is you would need to design a different front brake system.

jsl · Aug 7, 2018

Yes, I did have someone point out that a front hub may work.

The bike has rollerbrakes front & back; unsure if there's a way to modify the front fork for either (a) disc brakes or (b) V-brakes / caliper brakes (and how does that work with regards to power cutoff?)

2old said:
As long as you're not dealing with steep hills or slippery terrain, your situation may be tailor-made for a front hub installation. The only drawback that I can perceive is you would need to design a different front brake system.

JayLonghorn · Jun 30, 2019

Were you able to make something work? I have a Babboe Curve that I’d like to add an electric motor to.

Rassy · Jun 30, 2019

I think the bike would be a good candidate for a BBS02 or BBSHD. A BBS02 would give you plenty of assist on hills in the lower gears, or a BBSHD if you need more speed going up steep hills.

I put a little bike together for my sister five years ago with a BBS02 and a Nexus 8 IGH. It's a great combination, and even with slanted dropouts and no chain tensioner she has had no problems in that area. With the horizontal dropouts you should have no problems there either. Of course her's is a lighter bike, but it climbs a 20% grade with no problems in a low gear.

As mentioned, you will probably have to either remove or modify the chain guard. As far as the BBSxx fit I can't tell what or if any modification would be required. You can find all the dimensions of the BBSxx, and if you get serious about it I have a BBS02 on the shelf and can give you specific clearance requirements. Someone close to your location may be able to let you test fit a unit.

Looks like no matter what route you take, some modifications will be required. Good luck with your project.

EDIT: One thought is a BBSHD with a longer axle. Then you could use some custom partial circle spacers to clear the splines. Would affect the chain line even more. I wouldn't be too concerned about using a larger chain wheel since the motor would compensate for the higher gearing, as long as you don't apply unreasonable power to the Nexus.

Bigwheel · Jun 30, 2019

JayLonghorn said:
Were you able to make something work? I have a Babboe Curve that I’d like to add an electric motor to.

From the looks of this a mid drive kit motor is to me not going to work, it would hang down way to low, especially because an HD would work best to move it.

Think about a strong wound for torque geared hub rear motor with your battery mounted as far down the seat tube as possible.

If you want PAS use a Sempu bb. I’d have a throttle on board for aid in getting going enough to effectively activate the PAS.

jsl · Jul 1, 2019

JayLonghorn said:
Were you able to make something work? I have a Babboe Curve that I’d like to add an electric motor to.

Short answer is I haven't done anything with mine.

Longer answer is a couple of people reached out to me with Babboes -- one specifically in Portugal [?] with a Curve, who installed the same motor that I was looking at (TSDZ2).
You're going to have to grind down the center spline that runs forward from the bottom bracket somewhat to get it to fit, and remove the chain glider. I think most are using a 34T chainring also since the stock Babboe one is 33T.

Good luck & feel free to reach out via PM as needed.

sjuft · Jul 16, 2022

jsl said:
JayLonghorn said:

Were you able to make something work? I have a Babboe Curve that I’d like to add an electric motor to.

Click to expand...

Short answer is I haven't done anything with mine.

Longer answer is a couple of people reached out to me with Babboes -- one specifically in Portugal [?] with a Curve, who installed the same motor that I was looking at (TSDZ2).
You're going to have to grind down the center spline that runs forward from the bottom bracket somewhat to get it to fit, and remove the chain glider. I think most are using a 34T chainring also since the stock Babboe one is 33T.

Good luck & feel free to reach out via PM as needed.

Yo! Im about to do the same modification for a tsdz2 on a babboe curve. But im curios if grinding 2 inches of that support center spline makes the frame weak?

nicobie · Jul 16, 2022

On that bike it seems like a rear hub motor would be the simplest way to go. I'd try it without rear brakes first before attempting to adapt something. On a regular bike the front brakes do most of the work and it looks like with this cargo bike it would be even more so.

E-HP · Jul 17, 2022

nicobie said:
On that bike it seems like a rear hub motor would be the simplest way to go. I'd try it without rear brakes first before attempting to adapt something. On a regular bike the front brakes do most of the work and it looks like with this cargo bike it would be even more so.

I noticed the factory E versions of the bike come in both a rear hub and a yamaha mid drive version. Here's a video with a Magic Pie conversion on a similar model:
https://www.youtube.com/watch?v=eFO0_2VDEfk

The mid drive looks good for steeper stuff
https://www.youtube.com/watch?v=kSkc8FyJr90

Mid drive kit on Babboe City cargo bike?

jsl

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amberwolf

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jsl

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2old

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jsl

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JayLonghorn

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Rassy

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Bigwheel

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jsl

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sjuft

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nicobie

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E-HP

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