Bafang 750 Watt 8Fun - Too much fun

I guess you've picked up by my "PopPopEd" handle that I am not one of the youngest to post on this forum. But here I am, having started a bike shop in Maryland 40 years ago, now living in the flats of Florida, but still doing single-track xc. About 6 months ago i began doing the homework to build pedal assisted bikes for me and my wife. My thought was to take some of the pedal mashing out of the hills (we vacation in Asheville, NC) and give us a bit of an edge on sugar sand xc and off road climbs.

The good news is that our bikes turned out much better than expected. Simply amazing. I picked up the name "Paul" with EM3EV on this forum and he was patient as I battered him with my early questions and followed up with wonderfully accurate technical support after the sale. Paul is a good guy and we are in the process of buying additional kits from him.

Our conversions started with decent hard tails, good front fork, wheels etc. I was careful to set up the 9-speed cassettes to have gear five aligned with the Bafang front chainring. We've never had a chain slip off.

I eliminated the use of the hand throttle and EBrakes. We simply pedal and within 1/2 turn of the crank, the motor is running. Stop pedaling and within 1/2 second the motor stops. Our hydraulic disc brakes can easily stop the bike, even before the motor stops in a panic. We use one of the "big green button" switches on the left side of the handlebar, shifter on the right. EVERY TIME WE SHIFT GEARS the green button is used to instantly kill the motor, pedal crank to switch the gear, release the green button while you are pedaling in the gear you want and away you go. Perfectly simple and if I need to kill the motor, the green button is always there if I need it.

The Bafang system takes a bit of getting used to....like 5-minutes. Basically, you start pedaling using the pedal cadence you like, say 60 cranks per minute. Then...and here is where it is more of an art than a science....select the gear that you'd generally use if you didn't have the motor. Pedal along as you increase the pedal assist level. You'll go faster and select a higher gear to avoid pedaling too fast and wearing yourself out. When on a single track XC I find that I'll play within a few gears and a few up or down pedal assist levels while I'm riding. For example, say I'm clipping along, pedaling normal and I see a patch of sugar sand. Without the motor, I'd get off and walk. But just for the fun of it, I'll downshift to 1st gear (remember to use the green button while you shift), punch up the pedal assist and crank like a madman. Sand flies and I plow through. Really too much fun.

Hills? Like 45 degree climbs? Again, with 750watts and a quick pedal cadence, up up and away.

Some tips...
1. Get the C965 controller and use the instructions to select the 9 step PAS program. I've checked the power of PAS 9 against the throttle only and the throttle is only a very slight increase in power, say 10%. I've removed the throttle since, just 9 step PAS now. I don't want an electric scooter. Hey, I have a 650cc motorcycle, why do I want an electric scooter? The feeling of PAS is truly fun. Like an Iron Man suit that looks like a bicycle. You pedal and the bike amplifies your effort. Bionic biking is here to stay.

2. I decided on a 9 speed cassette as I can use a heavier chain and I think the wider physical gap between the gears makes gear selection more precise. Sure I can get more gears with a 10 or 11 speed cassette but the chain is thinner and the cassette gear gap is thinner. Chain angle also increases to the crank. So I like 9 speeds, it's working for me.

3. Gotta have the green disconnect button to allow crank turning without the motor pushing during gear changes. Get used to using it.

4. Keep the motor spinning. If you can't find a gear to pedal at a steady pace and mash the pedals, slowing down the motor, it will overheat. Electric motors want to spin quickly. Slow them down under load and you will hurt any electric motor. Downsize your crank gear, increase the size of the granny gear in the rear cassette to keep from overloading the motor if you are really pushing on the climbs.

5. Place the green button and the PAS controller for the C965 next to each other and the next to the left handlebar grip. Rotate them such that you can use your left thumb to depress the green motor kill button while you change gears with your right hand, or use your left thumb to add/detract PAS. Make it ergonomic so your left hand stays on the grip and brake levers.

6. Be sure to adjust the chain length so there is good tension when in high (small cassette gear) but one or two links left to avoid over tensioning in the lowest "granny" gear.

7. Buy from someone like Paul who is willing to email answers to questions.

8. Be safe, wear a helmet since you are now averaging 20 to 30 mph on your knobby tire mountain bike. Really your speed with at least double if not triple. Force = mass times acceleration. You'll hurt a lot more hitting a tree at 25 than you will at 10.

PopPopEd

Good first post Pop, too much fun is so true,

Great post - and I'm with you in all respects......except (tut tut there always has to be a 'but' ha ha), I agree with you that I don't want en electric scooter as I'm always peddling however I really like having the thumb throttle for a quick getaway at the lights. My logic is that moving to the front of the queue at a red light, its best to get out of the way (on green) asap to stop the car drivers getting cranky that they were held up for a second or 2.

Hi Poppop, good post.
But I agree with joss that a thumb throttle override can be a godsend in some situations.
We have some bike paths with "walk only" sections ( eg up stairways !...yes, really !), where a normal cyclist will carry their bike, but that doesn't work with a 30+kgEbike and a old lazy rider !....that thumb throttle allows me to power the bike up those sections at as I walk beside it.
I also remember having an "unrepairable" flat a fair way from any fix, and again pushing an Ebike up hills etc, without power loses its charm very quickly.

Up on the moors where I ride there are often deep ruts where you cant turn the pedals so a thumb throttle is a must for me.

Hello PopPopEd - I'm not a spring chicken either. I took a good spill a couple of years ago and did some damage to my shoulder and knee when my bike stopped and I kept going... So now I'm much more careful and not inclined to go all that fast. My son has an electric mountain bike and I want to start going out with him to do some mild mountain biking. Without some help I know it would simply be too tiring for me to ride. Cost was also a big factor for me. I ended up ordering a Bafang BBS02 500w, 36v, with a 44T sprocket. I believe it has the C963 controller. (Don't have it yet.) I'm also contemplating building a battery pack with the Tesla / Panasonic cells listed on this forum to make a 37v 17ah pack. I'm hoping that combo will be decent for some mild mountain bike riding and also to ride around town and to the beach occasionally. My son's bike has the Bosch drive. By what I've read it is expensive, but not all that powerful. I'm hoping the 36v-500w Bafang can keep up. (I'm 170 lbs.) Do you know if it's true that the 500W is actually a 750W unit and just sold as a different unit for marketing purposes? Is the "green button" you mention something that comes standard with the 8Fun kits? Thanks for the tips in your post!

Good tips PP.
If the BBS doesn't have a green button (mine doesn't) just use the brake lever depressed lightly when shifting (my rear brake is cable actuated).
The Bosch system is rated at "only" 350w, but I rode one in some pretty hairy off road areas and (IMO) it's a beast. The power is easier to control than my 750w, 52V BBS. That said, the BBS is great for off and on road excursions.

I'm not going to be in any contest to try to beat my son but would be nice to be able to keep up. I'm wondering if I should have ordered the 48v unit or if they are really the same and can use a 48v pack on the 36v kit. I briefly rode my son's Bosch bike but it was a very short distance and not off road. It did seem to have a reasonable amount of power. As you pointed out, it is rated at 350W and I'm pretty sure the battery is a 36v pack. Based on that I went with the 500w 36v kit to keep weight and cost down not needing a more expensive battery. The 500w 36v was only about $10 less than the 750w 48v kit so not real difference there. I was guessing the China specs would be inflated and the 500W would be closer in reality to 350w. But the more I read it seems like maybe it is the other way around and the 500w motor is actually more capable than listed. One site said that some motors are under rated to comply with max power rules in some countries. This is all new to me. I don't even have it yet and I'm already talking about more power. LOL.

I installed my 500W 36v BBS02 this week and I'm VERY impressed with it. It is nearly silent and quite smooth. Rode it up a few grassy hills at a nearby park and meter was showing almost 1,000 watts being sucked up on the climbs. That puts it near the 25A rating for the motor. I probably should use a lower gear for longer climbs. Power was fine for me. I hooked up some of my RC hobby packs together to create a 4A 10S 37V pack. It is good for about 8 miles of a mix of ECO and POWER mode riding through the park.

One thing I'd like to change is the level of the assist in the lowest ECO power mode. On ECO I'd like less assist as it still pulls away quite briskly and that uses more battery than I feel is needed for ECO riding. Also would like to have a PAS level 0 so I can quickly switch between human only or battery power. I need to do some research to see if the C963 can be programmed for those 2 things. If not, tapping into the brake switch and adding a button should do the trick to turn off the assist.

PopPopEd tip #8 is a good one. With no peddling my bike goes 27-28 MPH. On my very first ride I had a car make a left turn in front of me when I was going full speed. Using max front and rear braking, I stopped about 3 feet from the side of his SUV. The incident reminded me to mount my dash cam onto the bike... When you double your speed, you quadruple the force in a collision.

Why don't you just back pedal instead of spending on a green button and adding more clutter to your handlebars? Backpedal for an inch at the same instant as you trigger the shifter and your shifts will be clean and quiet, up or down. The backpedal instantly kills the motor and the few degrees of manual pedal rotation before the power kicks back in lets the chain climb or drop to the next gear before the motor torque hits.

What I have been doing is slightly pressing the brake when I shift and shift under pedal power only. I'm not so interested in a kill button for shifting, as using the brake works okay for me. I just want to easily alternate between stretches of no pedal assist without having to turn off the controller and then turn it back on again when I want a short burst of power. If I can program a level 0 into the controller that would be great.

It sounds like you didn't order your BBS02 from Luna, if you had it would have been reprogrammed to allow throttle in PAS 0 and if you chose to unplug the throttle you would still have a PAS 0 setting with no assist. Have you tried to access the two different programming levels on the display? See the online manual for your model display for instructions on how to get to them: it varies depending on your display, maybe the PAS 0 setting can be added w/o ordering the Bafang programming cable and connecting to a PC.

I ordered my BBS02 online before I found this forum and local US sellers. Not a big difference in price and I would have ordered from USA had I known. Fortunately it worked out ok but I've been burned before buying stuff direct from China / Hong Kong with something goes wrong. Sometimes not cost effect to deal with warranty issues.

I the ordered the USB programming cable and it arrived today. I think I can program 5 levels on the C963. I'll be playing with that tonight. No option for PAS 0 using the user accessible programming options on the C963 w/out cable. Hope with the cable I can set it up to my preferences.