Can I use my own crankset?

webmonkey8

New Member
I'm interested in the Bafang BBS-02, however I'm wondering, can I use my own crankset? I find that the one supplied with the Bafang kit is too high (teeth). I would like to use something like a 39T.
 

Gus

Active Member
You cannot use your own crankset but you can get a different chain ring. They make Bafang chain rings in a number of teeth sizes. I've seen as low as 42T and as high as 52T. 39T seems a bit low but this depends if you climbing mountains or want to go fast.

You can also buy an adapter (California eBike) that will allow you to bolt on 'normal' chain rings to your Bafang.
 

webmonkey8

New Member
Thanks for your reply, Gus!

Yes, I guess that's what I meant, a chain ring. :) I want to use a fat bike more for the mountains.
 

Aushiker

Active Member
You cannot use your own crankset but you can get a different chain ring. They make Bafang chain rings in a number of teeth sizes. I've seen as low as 42T and as high as 52T.
I don't suppose you have a link to the 52T chainrings? I have 46T and 48T rings but not seen 52T, at least not without an adaptor.

Andrew
 

Gus

Active Member
I don't suppose you have a link to the 52T chainrings? I have 46T and 48T rings but not seen 52T, at least not without an adaptor.

Andrew
Lectriccycles has them. I think Paul has them to, they are just not on his website.
 

Gus

Active Member
Thanks for your reply, Gus!

Yes, I guess that's what I meant, a chain ring. :) I want to use a fat bike more for the mountains.
Installing a Bafang mid drive on a fat bike is actually not possible. Most fat bikes come with a 100 mm bottom bracket. The bafang will only fit up to a 73 mm bottom bracket.

It can be done but involves a lot of work on the frame.
 

Gus

Active Member
@Gus and @Aushiker @webmonkey8 California e-bikes or w/e it's called, custom makes an extension for the bbos-2 to fit the fat bike 100mm BB.
Here's the Link. http://california-ebike.com/bafang-fatbike-mid-drive-product-announcement/
I pray no one is dumb enough to pay for that at that price point. That's almost a $1000 price increase beyond the stardard kit and you are only getting a longer axle and a BB extension collar compared to the standard kit. Save the money and just shave the BB down to 73 mm - this only works on some fat bikes.

I hope Bafang just realizes there is a decent demand for the fat bike mid drives and makes their own and offers it at a decent price.
 

Kaldeem

Active Member
So when ordering the BBOS2 from lectric cycles you get the option of the 46, 48 and 52 tooth chain-ring, I don't know the difference of why one is better than the other? Or what is good for a particular ride style.
 

John L.

Member
Generally, a smaller chainring (fewer teeth) will increase the number of pedal strokes required to go a particular distance, meaning, essentially, that it's easier to pedal uphill with a smaller chainring than a larger one. So, if you're mostly interested in hill-climbing, you'd be better off with a smaller chainring. If you're mostly interested in speed on relatively flat terrain, a larger chainring would be better. Of course, a lot depends on the gears you have on your rear wheel, too, so there are other variables, but that's a basic rule of thumb for chainrings. The Bafang mid-drive will also provide you assistance while pedaling, but The same basic rule holds.
 

webmonkey8

New Member
Wow! That is some expensive conversion just to extend the bb to 100mm! That's too bad. I might as well buy a new bike with that kind if money. Thanks, Gus, for the info.


I pray no one is dumb enough to pay for that at that price point. That's almost a $1000 price increase beyond the stardard kit and you are only getting a longer axle and a BB extension collar compared to the standard kit. Save the money and just shave the BB down to 73 mm - this only works on some fat bikes.

I hope Bafang just realizes there is a decent demand for the fat bike mid drives and makes their own and offers it at a decent price.
 
I'm interested in the Bafang BBS-02, however I'm wondering, can I use my own crankset? I find that the one supplied with the Bafang kit is too high (teeth). I would like to use something like a 39T.
If your not familiar with working out gear ratios sheldon browns gear calculator is an excellent tool, I work out what I need expressed in gear inches, it's more meaningful to me than percentages or gain ratios.
My bike pre electric conversion ran a 9 speed cassette and double chainrings, my gear range available was 26" lowest gear to 96" highest gear, for me this was a very good range of gears for my level of fitness and the hilly area I ride in the most.
For my e bike I knew higher gear ratios would be more usable, riding the bike with the 9 speed set up the bottom 3 gears became redundant I worked out a 36" bottom gear would be just about usable if I had no motor assist.
The sheldon brown calculator took the following info for my setup, crank length 165mm, chainring 42T, rear sprocket 16T, type of hub N360 nuvinchi, and tyre size mine are slightly odd size being fat I used 700c as closest in circumference.
My low ratio was calculated as 36.6" and high ratio was 131", in my head I knew 131" is a tall gear, on the road these are proving about right for my motor assisted set up, bottom is low/strong enough for my hill climbing and the 131" high gear means I can still pedal at 30mph+ without spinning out.
Hope thats of some help in working out what size chainring to go for, the bottom bracket width on fat bikes is a problem the conversion mentioned is more than I would want to pay out for.
Chain clearences are very close on fat bikes they run best on single or double ring chainsets, if you could remove enough metal to get the BB down to 73mm you may be best off running on hub gears or maybe a 7 spd setup, and would have to be very careful of the crank clearence of the chainstays.
Pic below is of my dropbar BT twin sport 1, I converted it to flat bar Hybrid and fitted a suntour swing fork for some suspension. My first BBS 01 kit was fitted on to try out the gearing and derailuer gears set up, I didnt like it too well when the motor was put on my surly I had decided to go with the N360 setup and had worked out what gearing best suited to me.
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LouisQ

Member
The 100MM is a great kit and from a fabulous supplier. An install kit is now available for a conversion. Given the price of a decent fat bike I don't see it as that out of line. Since Bafang is moving into the OEM builds I wonder if they'll bother with the fat bike market. USA is a tiny market compared to the rest of the globe. If fat bikes take off globally I think there's hope. But the Bike market in the USA is not unlike the scooter/Vespa market, a niche for larger suppliers by comparison to the rest of the global market..

Sam Dekok in AU has a chainring adapter for a very reasonable price. Lectric is gouging the BBSOx parts market. We have been organizing group buys and I manage them for Bafang parts. by buying together we save 10-15% on orders for small items on EM3ev total pricing. As much as 50-70% on some suppliers outrageous markups. Sadly base shipping by SAL is $19 and to that you have to add PyaPal fees, transfer fees and conversion fees. Still a chainring is half of what Lectric charges. I just sold a battery base for $30. Lectric wants $90 shipped. OUCH. That's IF you get LeGrand to respond. Several suppliers tell me they are getting business from the fallout that aren't getting serviced.

I got this adapter for $35 shipped from Sam in AU. http://ballaratebikes.com/collections/frontpage/products/bafang-bbs0x-104bcd-chainring-adapter
 
I ordered one those chainring adapters a couple of days ago glad to hear the quality of them is good. Am converting my girlfriends Pashley Princess sovereign to an ebike with the 350w BBS 01 kit I took off my bike. Am hoping this chainring adapter will allow me to fit the fully enclosed chain guard again. Bike is 3spd SA hub with drum brakes she will be using it to commute to work and back. When I completed the bike will post how it went together.
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LouisQ

Member
Excellent! I looked for a Pashley for 6 months. I wasn't willing to pay the cost of an imported bike. I made several offers, fell asleep on one that got away on eBay. I rode one two years ago. A marvelously constructed bicycle. Reminiscent of the bike we found in the 50's. High quality welds and excellent finish on a sturdy daily rider. Being disabled makes the step through a perfect bike, but a townie or flat foot, crank forward frame is just as accessible. Her bike will be a perfect combination of bike and motor. My only concern, and being conservative will solve it, is shifting under load. I have a Trek Pure with the same motor and SA with drum brakes, it's important to not shift while the motor is running. Either a tap of the kit brakes or as I do, I seldom if ever shift. Under assistance with the small chainwheel it will be very easy to start in 3rd gear and with that gearing it won't be hard on the motor at all. I have a 48T x 11T townie style that I ride on the flats and never take it out of that gearing, except on ice and snow. I'm about to go the opposite direction and add a 52T. I do wish I could fit the original chain guard on my wife bike, but she likes the gearing as it is 48T with 11TX34T cassette. I'm importing another stock of Bafang Parts this month, the 52T is getting popular with flatland riders.
 

LouisQ

Member
I ordered one those chainring adapters a couple of days ago glad to hear the quality of them is good. Am converting my girlfriends Pashley sovereign to an ebike with the 350w BBS 01 kit I took off my bike. Am hoping this chainring adapter will allow me to fit the fully enclosed chain guard again. Bike is 3spd SA hub with drum brakes she will be using it to commute to work and back. When I completed the bike will post how it went together.
View attachment 2121
Sorry, forgot to mention. You saw it comes unpainted? I just did an alcohol wash and a good rub out with coarse steel wool and rattle can painted mine. The finish came out quite nice. The Trek Pure like your Pashley looks better with a chain guard.
 
Thx Louis the pashley is a nicely made bike we picked it up 2nd hand it had hardly been ridden,there are plenty to chose from over here we only live bout 15 miles from the place they build them.
I will set the rear brake a little slack to facilitate cutting the power for gear shifts I doubt she will change gear much her winter ride to work is almost all downhill or flat, the ride back is uphill with a long sustained climb of a mile plus steep in places.
The standard gearing on the pashley is a touch high so should be about right with motor assist, won't be much point gearing it higher as she does not like riding fast.
In spring and summer her ride is about 20 mins a flat and very pleasent journey along the canal into town centre, with no cars and mostly only other commuters on bikes.
Did think the adapter plate looked bare metal no problem to give it a degrease and spray job, will mount the lithium ion bottle battery onto a rear PDW paydock rack, am looking for a small oblong wicker basket to conceal the battery.