Converting to 2-3 chainring gear system

Do Bafang kits exist to make the crank sprocket 2-3 teethed sprocket instead of the 1 only? I want to convert a semi-recumbent bike into ebike with mid drive motor. It has 3 teeth by default. Your thoughts? I have BBS02 and BBSHD kits.

I was told that adapters for the chainring would do this?

Can someone point me to good/cheap direction for one of these solutions? Perhaps aliexpress?

Thanks

Amazon.

Are you aware that you can get rear wheel cassettes up to 11-50t in range?

flat tire said:

Amazon.

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Hello

Yes thanks for replying

BUT what do I look for ? I don't even know what to look for on there or anywhere else?

Balmorhea said:

Are you aware that you can get rear wheel cassettes up to 11-50t in range?

Click to expand...

Can you paste a link to somewhere to this? I am not aware of this at all NOR know what you mean

halfeuro said:

Balmorhea said:

Are you aware that you can get rear wheel cassettes up to 11-50t in range?

Click to expand...

Can you paste a link to somewhere to this? I am not aware of this at all NOR know what you mean

Click to expand...

Using a cassette with very wide range means having all the gears you want without using a front derailleur.

https://singletrackworld.com/2018/02/review-11-50t-mx80-cassette-from-sunrace-1x11/

You can easily get 11-40 cassettes in 8 and 9-speed, and 11-50 in 10, 11, or 12-speed. You may need to switch your derailleur to one with higher capacity, or at least mount your existing derailleur on an extension like the Wolf Tooth RoadLink.

wow cool thanks!

This may be cheaper and more reliable than the other solution I am asking for, right?

Cool I will look into it

Knw of a good place to get this extension casette?

Balmorhea said:

halfeuro said:

Balmorhea said:

Are you aware that you can get rear wheel cassettes up to 11-50t in range?

Click to expand...

Can you paste a link to somewhere to this? I am not aware of this at all NOR know what you mean

Click to expand...

Using a cassette with very wide range means having all the gears you want without using a front derailleur.

https://singletrackworld.com/2018/02/review-11-50t-mx80-cassette-from-sunrace-1x11/

You can easily get 11-40 cassettes in 8 and 9-speed, and 11-50 in 10, 11, or 12-speed. You may need to switch your derailleur to one with higher capacity, or at least mount your existing derailleur on an extension like the Wolf Tooth RoadLink.

Click to expand...

halfeuro said:

Knw of a good place to get this extension casette?

Click to expand...

How many speeds do you have in your rear gears now?

Before conversion it was 21 speeds.

Now with the 3 teeth missing in the sprocket front, I only have 7 speeds from the back.

Let me know?

Thx

halfeuro said:

Before conversion it was 21 speeds.

Now with the 3 teeth missing in the sprocket front, I only have 7 speeds from the back.

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Using a 7-speed shifter limits your gearing options somewhat. The widest gearing range available for 7-speed is an 11-34 cassette, which is still pretty good.

It more sharply limits your gear range to use a 7-speed screw-on freewheel, which are available in 13-34 at the widest, and more commonly 14-34 or 14-28. A screw-on freewheel is a bad idea for a mid drive like BBS02 or BBSHD, because the increased chain tension will promote bending and breakage of the rear axle. That's already a problem even without motor power, which is why cassette gearing has superseded freewheel gearing.

So do you have a cassette or a freewheel? And what's the gear range you have right now?

When you have help from an electric motor, you don't need all the gears you get from a triple chainring setup. But it's good to have a wide range of rear gears, especially at the low end. It's the relatively low ratios that keep the motor spinning cool and efficiently.

Simply stock everything!

I want to minimum put 2 gear ring on the sprocket. Not 3 as I really want.

halfeuro said:

Simply stock everything!

Click to expand...

There is no "stock everything" when we don't know what kind of bike you have. New bikes come with anything from one to twelve gears in the back, with different kinds of cassette and different kinds of freewheel that won't work together. If we know what you have now, then we can make recommendations about what would be the easiest and cheapest way to expand your gear range.

I want to minimum put 2 gear ring on the sprocket. Not 3 as I really want.

Click to expand...

There's is no good way to do that. Normal sized middle and inner chainrings won't fit around the motor housing, and normal front derailleurs won't move far enough outward to reach the places where you could put them. If you managed to work around these two problems, you'd have really bad chainline between the front and rear sprockets.

Forget about having multiple front chainrings. BBS02 and BBSHD don't allow that. Work on getting all the gearing range you need in the back.