Anybody ride with a BBS02 mostly unpowered?

[bigun]

I am curious whether anyone here rides a bike with a recent BBS02B, but uses it mostly unpowered. I'm thinking about fitting this on a bike that I would ride 80-90% of the time without a battery. My normal commute is short, and I would only attach a battery when I'm going long distances. I'm aware of the extra weight I'd be carrying around, but are there other considerations that would ruin the bike when it's unpowered?

I searched to understand the resistance added by an unpowered BBS02B, and it seems that recent models do not add much pedal resistance. I'm also aware that the Q factor will be increased, and this could make the bike less comfortable or ergonomic vs. the stock configuration. Are there other considerations? Curious to hear from anybody who uses (or has attempted to use) a BBS02B in this way.

Here is a bit more context on my situation: A couple years ago, I built an e-fatbike based on a Motobecane Boris X9 with BBSHD. It was stolen about 6 months after I bought it. I enjoyed that bike, got it out in the snow once, which was awesome, but I didn't enjoy the spectacle of riding a fat bike around town.

I still have the e-bike bug though. I recently ordered a BBS02B during an Ebay 15% off sale, got the full kit with a 750c display for a bit under $400.

I have two possible donor bikes. The first is the one that I ride every day to work (< 2 miles each way). It is a Novara Mazama (image below). I really like this bike, and would love to extend its versatility by having a power option. My plan would be to use Ego 56V batteries in a bag on the rear rack when I wanted to have a power assisted ride.

The 2nd possible donor bike is an older Motebecane 700HT MTB. This bike is currently out of service, and will need some maintenance before I could use it with the BBS02B. If I use this bike, I would then have a dedicated ebike, and a dedicated human powered bike. All things equal, I'd prefer to have one "do-it-all" bike - but maybe that's a bad strategy. Appreciate any thoughts on this.

 

[neptronix]

You can do it, but a geared motor would be a better choice if you don't need crazy hill climbing abilities. Even still, for a short period of time, you can absolutely beat on a geared motor for a while and then let it cool off as you descend down the hill, if your usage is not continuous..

A geared motor equivalent of the BBS02 would be a bafang G310, which comes in at less than 6lbs and can be expected to sustain 700w of power for quite a while... as a bonus, it won't introduce a 10-15mm extra offset on the right side crank, which would could lead to your leg muscles eventually becoming disbalanced if you were to pedal on it a lot.

 

[Grantmac]

You definitely sound like a good candidate for a Kepler drive. Then you can add or remove it as needed.

 

[BotoXbz]

I was driving around with a BBSHD and no battery for a while, there is no resistance from the motor when pedaling.
However the motor does add some weight to your bike and you're missing a lot of gears, I had to climb a slope by driving zick-zack with my bike

 

[2old]

I ride a BBS02 off road without power 50+% of the time (flat terrain and descending). The added resistance seems minimal, but the 10 pound weight addition is noticeable. Biggest considerations are: 1) there is only one chainring, so you need to decide on gearing, and 2) the the right and left crank arms differ in distance from their respective chainstays by 10 - 15 mm. This can be rectified with Lekkie offset crank arms.

 

[tomjasz]

I ride two bbs01’s 350W. I have two new bbs01b motors to replace them. Great motors if you can manage to ride them within their limits. We use them on busy bike/walking/skating paths were high speed ruins the vibe. I really like these motors.

 

[bigun]

Thank you for the responses.
I am assuming the Kepler drive would be noisy/"buzzy", and that would be a deal breaker for me. If this is not the case please reply.

The Bafang G310 looks like an attractive option. We have some hills, of course, but they are not ridiculous. The hub itself seems pretty stealth, and the weight penalty seems reasonable. I am especially curious about a G310 with a torque sensing bottom bracket. It seems like this might preserve my bike's current behavior, and give a really nice boosted ride when I decide to bring an Evo 56V battery along for the ride. I will search for builds like this and see if people have been happy with them.

One concern - after mounting a hub, CA3, BMS, torque sensing BB, and routing the battery cables to the rear rack, I may wind up with cables everywhere and a Frankenstein looking bike. My previous BBSHD build was pretty clean with a triangle battery pack. It really helped that this bike's paint was flat black.

The BBS02B I ordered arrived in the mail today. I'm not intending to take it out of the box until I decide what I'm going to do - if I decide to go with a hub I may wind up reselling it.

 

[Chalo]

My guess is that once you BBS02ify a bike that you like the way it is, you won't like it after that (unless you use the power assist). My BBS02 is enough weirder than my unpowered bikes that it would drive me crazy to ride it without juice. I don't really trust the durability of the clutch or crank spindle enough to use them as the main propulsion.

If I were going to add e-assist to a bike that I intended to ride unpowered a great majority of the time, I'd probably go for something like a Q100 or Q128 geared hub motor and a bottle battery with integrated controller. Clean, simple, efficient, lightweight-- without messing up the pedal drive.

 

[2old]

From my perspective after three+ years of riding off road at least twice a week on it (I ride a pedal-MTB twice a week too), the BBS02 pedals fine unassisted, and I've never had a mechanical problem or any other malady with it.

 

[dustNbone]

It's fine for the relatively short amounts of time I ride it unpowered, but if it was going to be MOST of the time I'd really want to somehow deal with the weird pedal offset. That will screw with you over time.

 

[donn]

So ... ignoramus question: are Bafang mid drive motors fixed, in the sense that without electric power you will be turning the motor over anyway, when you pedal, and incurring some electro-magnetic penalty however slight?

Unlike geared hubs, which apparently have something like a free-wheel that cuts the motor out of the action.

This is the impression I get from the above. I'm sure the penalty is not very much, but then it's not very much on my direct drive hub, and I don't think I'd get away with telling people it's so near nothing it's not worth considering.

 

[BotoXbz]

So ... ignoramus question: are Bafang mid drive motors fixed, in the sense that without electric power you will be turning the motor over anyway, when you pedal, and incurring some electro-magnetic penalty however slight?

Unlike geared hubs, which apparently have something like a free-wheel that cuts the motor out of the action.

This is the impression I get from the above. I'm sure the penalty is not very much, but then it's not very much on my direct drive hub, and I don't think I'd get away with telling people it's so near nothing it's not worth considering.

On my BBSHD the motor/rotor is not spinning when pedaling.
You can clearly feel and hear it when pushing the bike backwards however.

 

[dustNbone]

There is a sprag clutch (fine pitch) that allows the motor to freewheel. It does have slightly more resistance than say the freewheel in your wheel but it's very minimal. It was a bit stiff when new but loosened up after a few miles.

 

[2old]

It's fine for the relatively short amounts of time I ride it unpowered, but if it was going to be MOST of the time I'd really want to somehow deal with the weird pedal offset. That will screw with you over time.

The Lekkie crank arms, while being much higher quality than stock, accommodate the difference of the stock ones by offsetting the left side.

 

[Grantmac]

There are videos of the Kepler and it's not obnoxious. It's very easily removable and light weight which is the main selling point.

 

[bigun]

My guess is that once you BBS02ify a bike that you like the way it is, you won't like it after that (unless you use the power assist). My BBS02 is enough weirder than my unpowered bikes that it would drive me crazy to ride it without juice.

You're probably right about this. The more I try to envision it, a BBS02 on a bike that will be powered 10-20% of the time feels like a mistake.

I was leaning toward a lightweight geared hub, but:

You definitely sound like a good candidate for a Kepler drive. Then you can add or remove it as needed.

There are videos of the Kepler and it's not obnoxious. It's very easily removable and light weight which is the main selling point.

I took Grantmac's advice and checked out the Kepler, and I'm sold on the idea of trying this drive. It does seem to be the closest match for my goals. I know rain is an issue for friction drives, however, I'm in Northern CA, and we don't get excessive rain here. I probably wouldn't be doing long rides in the rain anyway. If/when I get the Kepler running I will post an update with impressions.

I appreciate all of the responses and insight!