Chainring selection

Browneye

Well-Known Member
What Thomas is saying, if I'm not mistaken, is that with the high-torque physical design of the HD Bafang, is that these two options are your best - Luna Eclipse or Lekkie Bling. Luna has them both.

I apologize for not recognizing the uniqueness of this drive. Thomas is very familiar with these and will steer you right.

Notice how offset is built into the Luna Eclipse chainring:



And on the Lekkie:

 

Thomas Jaszewski

Well-Known Member
the high-torque physical design of the HD Bafang
Torque won't affect a non-dished chainring, it's chainline that is thrown off. However, I may well be wrong, you may still be right and the engineering intent of the dishing may well have affected the stresses on the motor. I have seen more trashed gears with 36T, flat, sprockets. I never considered the torque and design intent. But then horticulture is a long way from mechanical engineering... Increased dishing of the aftermarket chainrings has meant a wider range of bikes could utilize BBSxx series kits.
 

Thomas Jaszewski

Well-Known Member
Here's a photo I did in 2016. Now with measurements edited out by electricbike.com/forum moderators.
The middle is a chainring with a spider, not offset. For Browneye the "Luna 42T" is the one you found on Aliexpress.
I had all Luna Eclipse, but o my 7 speed bikes. All my former BBSxx bikes were or are 7 speed, the Lekkie gives me the best chainline fit.
Screen Shot 2019-12-12 at 12.38.55 PM.png
 

Thomas Jaszewski

Well-Known Member
So, you can't just leave the spider and change the gear sprocket ? Just trying to learn.
There is no separate "spider" on the BBSxx series motors. The chainwheels, OEM and typical aftermarket, are one piece and dished. See the center large chainwheel in my picture. That is a standard chainwheel on a spider. It's essentially flat. As a result, on the BBSxx series it typically screws up the chainline.
 

TForan

Well-Known Member
There is no separate "spider" on the BBSxx series motors. The chainwheels, OEM and typical aftermarket, are one piece and dished. See the center large chainwheel in my picture. That is a standard chainwheel on a spider. It's essentially flat. As a result, on the BBSxx series it typically screws up the chainline.
I see. I didn't know it was one piece. Thanks !
 
So changing the cassette is not as big an expense as the chainring? Is this a common thing for a bike shop to do?
I am handy just not familiar with bikes. Please do not think i am ignoring anyone or dismissing the suggestions. I e mailed Lina and i am waiting for a response.
This is a lot to digest and obviously even those in the know have questions and discrepancies.
I have a mechanic background and thought changing the front sprocket would be easier than changing the cassette.
I have changed sprockets on motorcycle but never a cassette on a bike. I am in no hurry and one to do this once and do it right .
I thank everyone for their suggestions and will let you know what happens
 

TForan

Well-Known Member
So changing the cassette is not as big an expense as the chainring? Is this a common thing for a bike shop to do?
I am handy just not familiar with bikes. Please do not think i am ignoring anyone or dismissing the suggestions. I e mailed Lina and i am waiting for a response.
This is a lot to digest and obviously even those in the know have questions and discrepancies.
I have a mechanic background and thought changing the front sprocket would be easier than changing the cassette.
I have changed sprockets on motorcycle but never a cassette on a bike. I am in no hurry and one to do this once and do it right .
I thank everyone for their suggestions and will let you know what happens
You just need a cassette tool and it's a simple job. Hell, I did it !
 

indianajo

Well-Known Member
If you have a "freewheel" that screws on, you just wrap an old piece of chain around a sprocket, grab it with a big slip joint pliers, and rotate. Chainwheel tool if I understand the pictures just has a piece of chain attached to a lever. Not worth cluttering up my toolbox. I have to keep big pliers anyway to open pickle jars anymore.
 

Thomas Jaszewski

Well-Known Member
So changing the cassette is not as big an expense as the chainring? Is this a common thing for a bike shop to do?
Yes, no big deal. I watched a youtube video and bought the tools, but taking the wheel into a bike shop and having them do it shouldn't take more than 15 minutes, for a slow mechanic, in shop time.
Personally I think it's worth investing in the tools. See Park Tools for a video on using their tools.
I e mailed Lina and i am waiting for a response.
This is what I do, support BBSxx customers and kits. But go ahead and wait to have them give you the same answer....
I've been supporting BBSxx series customers for several resellers since December 2015. This is my current full-time retirement job. Customer support for BBSxx users. I have one, or have had one of every model from the 2014 first release to the current BBSHD, and everything in between. Current list, 2 BBS01 350W, 2 BBS01B 250W, 1 BBS02B 750W, Had 3 BBSHD 68, 100, 120MM versions on commuter bike, fatbike, and stepthrough. As an old guy, I found BBSHD to fast and sold them all in favor of bikes that run 15-25MPH max. I've also owned ALL of the Luna Eclipse and bling rings and now run Lekkie 42T and 36T on two bikes. In addition to selling and supporting Lekkie rings.
 
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42 tooth worked great changed what i would estimate a gear and a half. bought the tool kit for $25 and it took 10 minutes.
The chain line looks good still some clearance between chain and housing. I did not even take out a chain link seems fine. Shifted through the gears and everything seems great .
Changing to tubeless on lunch today i hope!
 
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Wagonrd

New Member
I have watched videos, read google searches. After only putting 60 miles or so on my e bike I want to gear it lower.
First gear is crazy fast with full throttle on sand trails. I have a 1000 watt mid drive Bolton e bike 26" fat tire bike.
I noticed the bike seems to go fastest on the road in like 3rd gear ( it has 7)
My thinking is changing the front chain ring to a smaller one can only help?
Gearing it down i might have to use the higher gears on the street but it would pull real nice on sand and hills.
When i checked with Bolton they said the chain ring has little offset since it was designed as an e bike??
I do not need to go 35 mph on an e bike even on the road.
Any suggestions where to get a proper chain ring? should i go to an e bike shop? ( i was a truck mechanic so handy but worried about getting the correct gear)
is there any drawback to gearing it lower
I installed a Luna Cycle 30 tooth mighty mini chain ring on my BBSHD Kit. This chainring has a huge offset towards the downtube and aligns the chain more with the larger cassette sprockets. I then dismantled the 8 speed cassette and rearranged the sprockets so that only 5 sprockets were used. Then set the derailleur stops so that the chain will not derail. My bike is an offroad mtb, so low speed and torque are my goals.
 
Wagonrd, exactly what i was trying for but obviously you are more accomplished than i am lol great information and i will work up the courage for more changes in the future