PatrickGSR94

I'm about to pull the trigger on a BBS02 750W mid-drive kit for my utility bike. I've settled on Luna Cycles as the distributor to order from. I plan on going with these choices:

- BBS02 750W mid-drive motor $449.95 base price
- 44t chain ring (may upgrade to a different ring later)
- Luna full color display $45
- Bafang left thumb throttle $10
- Bafang brake handles w/ cutoff
- Bafang programming cable $19.95
- Gear sensor for derailleurs $45
- Luna wrench $19
- Battery: Shark 52V GA 13.5ah $495
- 52V Advanced 300W charger $79.95

Total price: $1,163.85.

Any thoughts or suggestions on other parts or options I should look into? This will be going onto my steel MTB frame custom built into an upright-riding utility bike that I use for grocery hauling in a trailer or general tooling around town. I just installed the 2.15" Big Apple tires and SKS fenders a couple of weeks ago. It currently has a 46/36/22 triple and 11-28 8-speed cassette. So with the BBS02 system it will become 1x8 with a 44t ring and 11-28. I will keep my right brake lever with 8-speed integrated shifter. I'll remove the left brake lever and 3-speed shifter combo, and replace with the Bafang front brake lever with cutoff, and the thumb throttle. Or I may just start without the throttle and use PAS only.

Robert C

It isn't a bad list, it includes more than I purchased. I do agree on the throttle with the bafang. The PAS has a bit of lag and is had to shift without a throttle.

I ended up putting a NuVinci hub on my trike with the bafang. I saw no reason to get a programming cable.

I am also not so sure that you will need both a gear sensor and a throttle. As I understand the gear sensor, it detects a change of tension on the gear cable and cuts to motor; with a throttle you can do the same.

The bike itself looks fine for the conversion.

Doc_Wui

-Color display might be easier to read in bright sunlight.
-Luna wrench is pricey, but works much better than a channel lock pliers. I ordered mine after the BBS02 came loose.
-You really going to reprogram the controller? I didn't want to complicate my life.
-I have a left thumb throttle too. Usually pedal though.
-Gear sensor. Nah. I rode motorcycles for years. Just roll off the throttle or back off the pedaling when shifting. It's not like you need to race thru all 7 or 8 gears on a bicycle.

You have a crank puller? Does the chain use a master link or will you need a chain breaker to unthread the front derailleur? By the way, chain breakers are mainly for emergency repairs. The link often binds when pushed back together. Unless you fiddle with it and make sure it's free, it can make the chain skip. Been there.

2old

Just FYI:
1) The battery indicator is pretty useless with 52V; it'll show you when the battery is really down though.
2) You don't need as many gears with the motor; depending on your chain line, you could use ferew gears. My chainline was terrible so I'm using 11-17-28 which is fine. The 17 is "straight" so the chain doesn't have any strange angles.
3) As DW said, Luna sets the BB up with a 25 amp controller; you want to mess with that?
4) Didn't need the gear sensor; when I remember, I just touch the brake when shifting which you don't need to do very frequently IMO.
5) Hopefully your discs are mechanical because the cut off is valuable off road if you're like me and the bike ever getsaway from you on a steep hill.
6) The throttle is exceptionally valuable when you're trying to make a light.

PatrickGSR94

Thanks for the tips. Yes I have Avid BB7 mechanical discs which feel awesome. I'm not even sure if I'm going to hook up the throttle. I really want it to be pedal assist mainly.

I have all the tools. I built this bike up myself from a bare frame a little over a year ago. All my bike chains have KMC Missing Link master links on them.

Do you think the gear sensor isn't worth it? I read something awhile back saying that it either wasn't made well, or didn't work well, but I wasn't sure if they've been improved since then. I thought it might be useful to have it in case I don't want to wait for the cadence sensor to tell the motor to cut off, and I forget to pull the front brake lever before shifting gears. I've read that shifting with the motor engaged too often can wreck the drivetrain.

Dunbar

Not trying to change your mind but a refurbished Juiced Bikes Cross Current goes for about $200 more with a 500Wh battery. That comes with a torque sensor and hydraulic disc brakes.

https://shop.juicedbikes.com/collect...nt=29189943058

BruceMetras

I've done 4 BBS02 conversions on a variety of bikes.. I'd pass on the gear sensor, like others have said, a tap on the brake, or a slight backpedal (shuts motor instantly) .. also programming the 'decay' when you stop pedalling also helps .. I've used the programming cable on all of the bikes I've done.. being able to fine tune the assist levels with regards to speed/amp draw I've found to be valuable.. especially if you want the mid-drive mainly to assist your pedal power as opposed to throttle operation .. you can easily scale back the the individual level settings to greatly extend your range while keeping your amp draw to a minimum for the speed that you want to attain.. personally, I ride my road bikes at 22+ mph shooting for between 200 to 250 watts .. range with a 13 amp/hr battery is generally over 60 miles

PatrickGSR94

Not practical for my use as a utility bike. I built this bike to be upright-riding, comfortable, large tires, fenders, rack, for hauling my trailer to the grocery store, and now with e-assist I should be able to use it regularly for my 31 mile round trip commutes on days that I don't use my regular road bike commuter. Thanks for the suggestion, though.

kickstart

I hardly ever use the throttle on my Radwagon, but its very beneficial the few times I use it.
There is some lag before the PAS kicks in which is normally ok or even desirable, but when entering or crossing a busy road on a hill the immediate application of power is a real plus due to the extra weight. Its also very helpful if you end up stopping in a high gear, just get going on the throttle momentarily and down shift as needed.

Dunbar

Fair enough, but I've got all of those things on my Cross Current. I've got 29x2.0 Marathon Almotions on mine and it will clear 2.15's. I regularly carry 30-40lbs. of groceries on it. All you would need is some riser bars or a stem riser to raise the handlebar height. I'm currently running one of the early 840Wh batteries on my bike.

NoPhart

Correct me if I'm wrong, but doesn't the color display allow you to "tune" without the need for the extra cable? If correct, then maybe go for the color display over the tuning cable.

Robert C

I have the colour display and it allows some selecting, but not tuning. As an example, I would like to be able to carefully control the watts out, in order to better match the motor to my solar panel. This is something that would need the programming cable.

Here is a link to the manual.

PatrickGSR94

Yeah I've seen a few articles on preferred settings that would require the programming cable, so I plan to do that. I'm all about tinkering and tweaking cars, bikes, computers, etc. so I should be right at home doing some tweaks to this system.

I'm sure it could be made to work okay. But my bike is pretty much ready to go. I took my old MTB, plus $300 in parts, and made 2 bikes out of it - the utility bike pictured above, and my old MTB built back up as a rigid gravel grinder using mostly spare parts. So factor that in, and I'll really only be out a little over $200 above the cost of the Bafang setup.

2old

Not to hack (too much), but is that a Body Float seatpost Dunbar and, if so, how do you like it and do you think it would be useful off road?

Dunbar

I don't use the Body Float off road but I love it on road. A rigid aluminum frame cruising at 25-30mph is really harsh. The Body Float works very well and is very adjustable via the different springs they sell and the preload adjustment.

PatrickGSR94

heh maybe I won't need a special seatpost since I have 2.15" Big Apple tires. Steel frame and fork also, but I think the seat post I'm using is aluminum.

PatrickGSR94

whoa wait, backpedaling makes the motor cut off? I haven't heard that before, but if true then that's very handy. I'll probably just do that quickly before shifting rather than pulling the brake lever or waiting for the motor to cut off on its own.

BruceMetras

All true! and we are only talking a little bit of backpedaling .. like an 1/8th of rotation.. the other thing to note, if you are using less assist, you can match your cadence to the BBS02 output and just shift normally as you would with any derailleur drivetrain.. smooth shifts, no problem..

Also, be aware that the Shark pack needs special care in regards to the mounting cradle .. the plastic tabs on the battery case are weak and break easily.. a Dolphin pack is much more robust, or a carbon Shark pack which has a totally different cradle, or even a bottle battery is superior in strength to the Shark pack..

PatrickGSR94

Thanks for the tips, I'll look into those other battery options. I never was really sure about the differences between Shark, Dolphin, Carbon Shark, etc.

BruceMetras

The Shark is less of a problem if you mount it more or less permanently.. then you can provide extra measures to keep it secure.. but that defeats the purpose if you are going to be taking it on and off the bike regularly.. I run the Shark on one of my bikes, but I leave the battery on the bike and use extra strapping material to stabilize it .. I broke a couple of the tabs early on.. I also run 4 mounts on the cradle, one that is drilled through the aluminum base.

2old

Dunbar, thanks.

Dunbar

After test riding 20+ e-bikes the two things I know that I want in a higher speed e-bike is a suspension fork and a suspension seat post or rear swing arm.

PatrickGSR94

Well dang, now the left thumb throttle is out of stock. I wouldn't really want to use any other type of throttle so I'll probably just go with the stock throttle and order the left thumb throttle separately later.

What about the 42t Lekkie ring, is it really worth the extra $90?

BruceMetras

It won't outlast the steel stock chainring.. the Lekkie will be much lighter and is certainly better looking.. also it is a narrow wide ring, so chain derailments would be lessened over the stock ring.. I run the stock steel ring and a dummy front derailleur to address the chain going overboard.. stock chainrings are also dirt cheap if you ever did wear one out, or wanted to change the ring for one with more or less teeth..

PatrickGSR94

Interesting... all my other bikes all have aluminum chain rings, including this bike pictured which has RaceFace chain rings that are 20 years old. Would the fact that it's 1x mean the ring will wear faster than a double or triple crank rings?

As I understand it, the Lekkie ring's dish shape makes for a better chain line than the stock steel chain ring. How true is that?