I moved the Luna BBSHD motor kit and parts over to another bike
Everything was great except the Luna Eclipse 42 tooth chain ring was hitting the chain stay
It needs about 6 mm reverse/positive offset to make it clear
Shimming the motor out away from the BB is not an option with my 120 mm BB and 120 mm BBSHD motor
Shimming the chain ring out 6 mm with spacers will not work
The chain ring would be hanging out in the air without any center support
The chain ring is only a couple weeks old and I really want to be able to use it again
In the mean time, I am using a Luna mini 30 tooth chain ring
It's a great chain ring, but not enough offset and not enough top end with an 11 tooth cassette gear.
So I came up with an idea to make an adapter to add 6 mm positive offset to the motor-chain ring
6 mm lets the chain ring just barely clear my frame
I made a mock up adapter out of plastic to test the concept
It looks to me like this idea will work if made from 7075 aluminum.
I would have to find a machine shop with a lathe because I only have a small hobby lathe
Or maybe Luna thinks this is worth a look?
Here's the mock up and how it works
The video has a full explanation and shows detail of how it looks on the bike
[youtube]u04NICHEQ5Q[/youtube]
Everything was great except the Luna Eclipse 42 tooth chain ring was hitting the chain stay
It needs about 6 mm reverse/positive offset to make it clear
Shimming the motor out away from the BB is not an option with my 120 mm BB and 120 mm BBSHD motor
Shimming the chain ring out 6 mm with spacers will not work
The chain ring would be hanging out in the air without any center support
The chain ring is only a couple weeks old and I really want to be able to use it again
In the mean time, I am using a Luna mini 30 tooth chain ring
It's a great chain ring, but not enough offset and not enough top end with an 11 tooth cassette gear.
So I came up with an idea to make an adapter to add 6 mm positive offset to the motor-chain ring
6 mm lets the chain ring just barely clear my frame
I made a mock up adapter out of plastic to test the concept
It looks to me like this idea will work if made from 7075 aluminum.
I would have to find a machine shop with a lathe because I only have a small hobby lathe
Or maybe Luna thinks this is worth a look?
Here's the mock up and how it works
The video has a full explanation and shows detail of how it looks on the bike
[youtube]u04NICHEQ5Q[/youtube]