New Bafang Crank-Drives

[skyungjae]

And here I was regretting I had a 46t ring up front! Ha ha... I have an 11 tooth gear in the back for top pedaling matching at speed but I'm certain that I will lament not having a 34t in the back to shift down to as a low gear for the occasional pedestrian ramp and hilly terrain. I think I need to search for an 11 - 34 8sp cassette.

http://www.ebay.com/itm/36-Tooth-Co...Cassettes_Freewheels_Cogs&hash=item3cdafabfe1

You can always get one of these and ditch the 12T and keep the 11T cog. :wink:

 

[0utrider]

You can always get one of these and ditch the 12T and keep the 11T cog. :wink:

Very interesting. Thanks for the link!

 

[johnrobholmes]

Made an interesting find today after watching the battery recharging closely for a while. I get the same "bad" efficiency of about 30wh/ mile whether I cruise at 18mph or 26mph average :? So taller gears it is, I'll enjoy the speed!!

 

[tahustvedt]

Made an interesting find today after watching the battery recharging closely for a while. I get the same "bad" efficiency of about 30wh/ mile whether I cruise at 18mph or 26mph average :? So taller gears it is, I'll enjoy the speed!!

That's just weird. When I tested my BBS01 250 W with throttle only I got 14.8 Wh per mile. 19.5 mph average speed in varying terrain. This was recorded while riding, not charging.

 

[dumbass]

Here's a question I've been wondering about. ac246 wrote a thread called "BBS02 750 Controller Dead" He explains in the thread that he was only able to ride a short distance when the motor stopped functioning. But he heard a slight click when applying the throttle. As so many of us have reported this same thing and some have replaced the controller. But he choose to take the controller out and replaced the FETs (with the same kind). And he found and corrected an incorrect motor setting and he now reports his motor is running fine.

So considering I have the same exact problem on one of my kits I have 3 questions for those who know controllers. 1) could the FETs be upgraded? (If so how do you determine the correct upgrade?), 2) is it possible to increase from a standard 6 FETs to 9 FETs? and 3) is there anyway to increase the max amps capacity of a controller? Say from a rated 20a to 25a.

Bob

 

[Seya]

Hi,

I remember reading the the BBS 02 750 watt will not work with a 36 volt battery.

Is this the general consensus here?

 

[Kepler]

No consensus required. The 750W unit is designed for 48V and has the LVC set to 41V internally. If you have the programming software, you can set this down to 38V as a minimum. Still not low enough for a 36V pack.

 

[Kepler]

Here's a question I've been wondering about. ac246 wrote a thread called "BBS02 750 Controller Dead" He explains in the thread that he was only able to ride a short distance when the motor stopped functioning. But he heard a slight click when applying the throttle. As so many of us have reported this same thing and some have replaced the controller. But he choose to take the controller out and replaced the FETs (with the same kind). And he found and corrected an incorrect motor setting and he now reports his motor is running fine.

So considering I have the same exact problem on one of my kits I have 3 questions for those who know controllers. 1) could the FETs be upgraded? (If so how do you determine the correct upgrade?), 2) is it possible to increase from a standard 6 FETs to 9 FETs? and 3) is there anyway to increase the max amps capacity of a controller? Say from a rated 20a to 25a.

Bob

Sure the Fets could be upgraded. The stock fets aren't too bad though which is nice to know. I believe 3077 Fets would handle more power. You could also go to 4110 Fets although there might not be a lot of advantage unless you wanted to modify the controller for higher voltage which of course would take other controller mods also.

You would need to keep the same Fet count though.

 

[tahustvedt]

I like the look of this new BBS. Looks like a nice improvement. The chain line is slightly better, and it has some small visible changes, but the biggest improvement is that the bottom bracket shaft is centered:

http://www.szbaf.com/en/components/component/motor/mm-g01350dv.html

 

[naitsirk]

What is the smallest aftermarket or bafang crank cog with offset?

My stock SRAM dual drive (3 speed inner and 7 cassette) had a 33t front. I'm using that 33t with the eBay adapter and two spacers. However I can't use the lowest two hill climbers (28 and. 32) because the chain falls off the front crank - pretty severe chain line issue.

I've seen the Italian 43 ( or is it 42), and I'm wondering if anyone makes something smaller.?
Clearly It has to be big enough to clear the motor so probably 37+ or so?

 

[Russell]

What is the smallest aftermarket or bafang crank cog with offset?

My stock SRAM dual drive (3 speed inner and 7 cassette) had a 33t front. I'm using that 33t with the eBay adapter and two spacers. However I can't use the lowest two hill climbers (28 and. 32) because the chain falls off the front crank - pretty severe chain line issue.

I've seen the Italian 43 ( or is it 42), and I'm wondering if anyone makes something smaller.?
Clearly It has to be big enough to clear the motor so probably 37+ or so?

That 42T ring is here: http://www.microsofttranslator.com/BV.aspx?ref=IE8Activity&a=http%3A%2F%2Fwww.alcedoitalia.it%2Fshop%2Fguarniture%2Fcorona-42-denti-per-bafang-centrale-bbs01%2F

For a while hi-powercycles offered their adapter/chainring on eBay but I don't see it now. They claim in this post the design of their chainring helps keep the chain on. http://endless-sphere.com/forums/viewtopic.php?f=28&t=60912#p940173
It looks like they use a Race Face single ring http://raceface.com/components/rings/rings/single-ring-narrow-wide/

Another thing you could try is what I do when I build a 1x bike, leave the front derailleur in place to act as a chainguide. I lower it to just clear the chain and center it with the adjustment screws (You don't need the cable or left shifter)



-R

 

[tahustvedt]

42 is the smallest that is practically possible to make with the stock chainline. 41 might just be possible if very thin material is used to offset the teeth.

 

[dumbass]

Here's a question I've been wondering about. ac246 wrote a thread called "BBS02 750 Controller Dead" He explains in the thread that he was only able to ride a short distance when the motor stopped functioning. But he heard a slight click when applying the throttle. As so many of us have reported this same thing and some have replaced the controller. But he choose to take the controller out and replaced the FETs (with the same kind). And he found and corrected an incorrect motor setting and he now reports his motor is running fine.

So considering I have the same exact problem on one of my kits I have 3 questions for those who know controllers. 1) could the FETs be upgraded? (If so how do you determine the correct upgrade?), 2) is it possible to increase from a standard 6 FETs to 9 FETs? and 3) is there anyway to increase the max amps capacity of a controller? Say from a rated 20a to 25a.

Bob

Sure the Fets could be upgraded. The stock fets aren't too bad though which is nice to know. I believe 3077 Fets would handle more power. You could also go to 4110 Fets although there might not be a lot of advantage unless you wanted to modify the controller for higher voltage which of course would take other controller mods also.

You would need to keep the same Fet count though.

Ok thanks. Was just wondering it an upgrade would eliminate future problems. I'm thinking one of the things that need to be looked into is how this poticular controller was programmed. Could be the only reason it failed in the first place.

Bob

 

[Tom L]

I rode to work this morning and as I parked my bike in the rack I noticed the LCD had turned off without me pressing the power button. I could not turn it back on.

I measure 53V at the charge port on the battery but only 26.5V at the main battery output socket. There does not appear to be any voltage drop across the fuse (measuring from the charge port + to the output socket +). It's one of these 11.6Ah versions from Lectric Cycles, http://lectriccycles.com/products/48v-downtube-mounted-battery

This battery generally has very light use, my daily commute is only 6.2km (80Wh, average use). However yesterday I went for a 25km ride and used 320Wh according to my wattmeter. This is less than 60% DOD and I would not have expected it to damage a 19 month old battery that has had such light use.

Do you think it is likely my BMS has died or is there a faulty cell?

I would like to measure all the individual cell voltages but the pack is rather firmly hot glued into the case. Is it ok to release this with a hot air gun?

 

[jateureka]

You can use a heat gun on the low setting if you are careful. I prefer to use a hairdryer.

 

[Tom L]

I used a hot air soldering rework gun. Finer temperature and air direction control. Worked a charm. Didn't have to take the whole pack out though. I noticed that the hot glue around the blade fuse holder was discoloured. Must have been a poor contact to the fuse, which is intact, as the holder has melted. Measure 53V on the hot side of the fuse so I'm going to replace it.

EDIT: fixed.

 

[amigafan2003]

Was it not under warranty?

 

[Tom L]

Nah, Its over a year old (19 months). I actually think the hot glue may have been part of the problem. Not sure if some got in there first and messed with the connection or it was just a bad contact to begin with but after that bad contact heated up hot glue did flow in there and made it worse. It was actually full of charred glue.

 

[mclark999]

Nah, Its over a year old (19 months). I actually think the hot glue may have been part of the problem. Not sure if some got in there first and messed with the connection or it was just a bad contact to begin with but after that bad contact heated up hot glue did flow in there and made it worse. It was actually full of charred glue.

Even though it's not under warranty, I'd still contact lectriccycle. You paid a big premium for local service. If nothing else, they should at least help you terrible shoot it.

 

[ediehl]

Just built my first conversion; used the 500W BBS02 and 36V 10ah battery pack from BMSBattery on my Trek 7500 Multitrack. Nice! On my first ride I learned that I should not attempt a tight u-turn with no space to run off, with both feet still in the pedal clips. Halfway through I give a gentle turn of the crank, and ZOOM, all of a sudden I'm lunging straight toward the roadside ditch. Grab the brakes, dump the bike. If I had thought about it beforehand I could have kicked my feet out of the clips first, or geared down to a lower gear, or better yet just applied enough pressure to either brake lever to not engage the brake but to prevent the motor from kicking in. Oh well---I didn't break anything, and I got to practice some cussing.

I'm now going to also convert mine and the missus' recumbent bikes. I think I'll buy two more BBS02 kits and just one more battery, since we'll never be using more than 2 bikes at once, and I can share the battery I already have between my Trek and one of the recumbents. I'm thinking about going with the 48 750W kit for the other recumbent, since it wouldn't cost all that much more to do so, but I'm wondering what the advantages or disadvantages would be. Our purpose for the recumbents is recreational touring; I have no desire to be making rocket launches or riding at high speeds. Range, and adequate power on hills are our primary needs. Assuming batteries of comparable amp-hour capacities, can anyone offer advice on the advantages (or disadvantages) of the 48V 750W versus the 36V 500W setups?

 

[0utrider]

Just built my first conversion; used the 500W BBS02 and 36V 10ah battery pack from BMSBattery on my Trek 7500 Multitrack.

I like your install and on that bike, it looks great! Thanks for the tip! I'm plan on testing the motor this comming weekend and I'll keep my hands on the brakes when manouvering in tight quarters to avoid shooting off into diches, ravines or walls!

 

[Tom L]

Even though it's not under warranty, I'd still contact lectriccycle. You paid a big premium for local service. If nothing else, they should at least help you terrible shoot it.

I did contact them but fixed it myself before I got a reply.

 

[paulbram]

Hello everyone. I just installed my very first motor in my bike! I've been having a blast with the BBS02 over the weekend and today I decided to try commuting to work.

First the basics:
Bike: Kona Mountain Bike 26" wheels
Rider: 195 lbs
Motor: BBS02 750W
Battery: 18.5 Ah 22p from em3ev
Commute Distance: 10 miles. VERY hilly

Here are a few observations/questions after my first few rides.

1. I rode 10 miles over the weekend yet the battery indicator always seemed to be reporting 100%. I plugged in the charger anyway but both the red/green lights were illuminated so I figured it must have still been at 100% which I thought was strange
2. When going up steep hills, the battery indicator would drop, but generally it would go back up to full once I leveled out.
3. On my ride to work, things were going great until about mile 8 when I approached a fairly long hill at which point the battery went down very quickly, started flashing, then finally everything just shut off. From this point on, I had to resort to backup power to get me the final two miles which is REALLY hard with a heavy battery attached!
4. Once I finally arrived to work, I immediately plugged it in to charge, but before that I tried turning it on and guess what? It reported a full battery! It is plugged in now, but again the charger is showing red/green lights so is it even taking a charge or not?

I realize these batteries can't go forever, but I guess I was quite surprised to see it go from reporting 100% to being dead so quickly. It seems as if going up hills is not something that can easily be sustained for an extended period of time. It also seems like some sort of recovery time is needed after long hills.

Sorry for all of the questions. I'm a little nervous attempting the ride back home as the steepest hill I have is right at the end of the commute!

Thanks

 

[0utrider]

when I approached a fairly long hill at which point the battery went down very quickly, started flashing, then finally everything just shut off.

Heat shutdown? Were you in an easy gear for the motor to go up the long hill? I'll assume your battery pack's cells are balanced.
Speaking of which, how much difference between individual cells is considered out of balance?

It does seem odd that the charger is showing a full capacity regardless of your usage.

 

[teslanv]

You are running a 14 cell battery, which runs high on the voltage scale for this drive.

Get a watt-meter installed on it, and program the controller to Max. LVC.

The battery LED's will always read "full" on the display, because the voltage is 8.4V higher than a nominal 12S battery, which I think is what this controller is set up for.

If you want I can help you get dialed in. I live pretty close to you.

PM me