Larry-vs-Harry Bullitt build advice BBS02 vs BBSHD?

I've got a 2014 Bullitt that I like, but it has a failed Bionx battery (and/or failed BMS) that I'm leery of investing more in. To that end, I'm thinking of switching to a mid-drive. I primarily transport kids to school and do some shopping. Not too much hills, maybe 15-20 mile round trip max. I was looking at the BBSHD and either keeping the rear with its 8 speed cassette, or maybe switching to a nexus 3 speed (I'd have to replace the Bionx rear hub drive anyway). I know the BBS02 is cheaper/lighter, but wonder if it would be sufficient for the Bullitt (55lbs), me (200lbs), and the kids (75lbs). My budget is somewhere between $50 (new rear hub, no electric) and $5000 (new e-bullitt), and to complicate things, my wife is getting a Tern GSD (she got a pretty good deal) that uses a Bosch powerpack 400 and has space for another - it would be cool to have compatible batteries. I'm a little handy with bikes, but any advice would be welcome!

Larry vs Harry Cargo Bike
http://www.larryvsharry.com/

[Moderator edit: added BBS02 & BBSHD to title and link to cargo bike]

I know of the Santa Cruz Bullit ...https://www.santacruzbicycles.com/en-US/archive/bike/bullit
But have not heard of your bike, or that it even has a e-bike version.
Where is an example of those bikes ?

What do you mean by , which would be sufficient ? With the right gearing, larger cogs on the back either of the Befangs would do , you would get more speed with a higher wattage motor like the HD, but then you would also use more battery capacity , so it would probably depend on how fast you want to haul the kids around at.

You know about the newer e-bike drivetrains ? like the new ( out in a month or two from now ) Box Components 9 speed drivetrain .
It is so new it is not listed on their website yet.
Someone going to Interbike 2018 in Reno/Truckee can look into this , as well as the new Sram Eagle NX 12 speed e-bike drivetrain,

For a Befang BBSxx the Box 9 speed would probably be the one to get.

The Bullitt is a Danish cargo bike (http://www.larryvsharry.com/)

The newer models have a split frame for drive belts, and some have Shimano STEPS specific frames, but mine has none of those cool features.

Mine had/has a Bionx drive that worked OK until the heat and years (I think) wore out the battery. Now that Bionx is no longer, I don't feel confident sticking with their proprietary stuff - hence the intended switch.

I have no real desire to race around with the kids at 30mph, but range and torque are probably more important to me

I have seen that on a gokart track going 40mph with a crstalyte rear hub. It was cool.

As a bbs02 owner, I will say the bbshd is worth the premium.

Even the newest bbs02 has a problem with getting hot when ridden hard, even when using pas and not throttle exclusively. With throttle only it will cook in minutes depending on gearing and load. The bbshd while still a mid drive and suspect to being lugged in inappropriate gears, is overbuilt compared to its rated power, while the bbs02 is underbuilt.

For a cargo bike, there should be no question.

The BBS02 is just fine running hard, if you're nice to it. The on/off PAS is probably the hardest thing on it, especially at low crank speed. If the crank speed is low enough to meaningfully add pedal power, it's going too slow to be getting full motor power.

I run mine at 25A with an external Grinfineon controller, and I've never managed to get it what I would consider "hot", and I climb some really nasty hills with it. It's done hours pulling 20-25A up mountain passes, at as high a motor/crank speed as possible, it's fine.

I start off under pedal power, and once the crank speed gets too high for me to be useful, I let the motor take over. At 48/52V it wants to spin faster than I can pedal, the PAS system is therefore pretty useless IMHO.

I did try a 36V battery that I was servicing on it, and that brought the crank speed down to a pretty comfortable level for pedaling along. If I was going to build an "exercise" bike with a BBS02, that's probably what I'd use.

I still wouldn't want a PAS system though, because I don't see what it accomplishes that a bit of throttle discipline can't. And it comes at the cost of control, which is something that I value a great deal on a bike.

dustNbone said:

I run mine at 25A with an external Grinfineon controller, and I've never managed to get it what I would consider "hot", and I climb some really nasty hills with it. It's done hours pulling 20-25A up mountain passes, at as high a motor/crank speed as possible, it's fine.

I still wouldn't want a PAS system though, because I don't see what it accomplishes that a bit of throttle discipline can't. And it comes at the cost of control, which is something that I value a great deal on a bike.

Click to expand...

Why run an external controller when the internal one is 25A too?

Pas is good to free up your hands since there is no cruise mode on this kit.

The internal controllers seemed to have some weatherproofing issues in very cold temperatures. I blew 2 of them one winter, riding in substantially below freezing temps, so I gave up and wired it up for an external. A shame too because I really like the Bafang controller.

FWIW they blew not while riding, but the next day upon power up. Inspection revealed the potting had come away from the housing, and I presume condensation caused a short. Twice.

For cruise control/free hands I just use an old school motorcycle throttle lock, wide open is usually fine as speed control is mainly through gear selection.

Would love to know what you ended up doing on the Bullitt. I'm in the exact same situation - Older Bullitt paired to a dying Bionx system, now without reasonable options. Now I'm not sure what system to invest in, or to switch bikes or what. I'd love to see a fully-complete Bullitt with a Bafang to compare.