Narrow Wide style front sprocket for 7sp FW?

[DukeMoto]

I've been looking for a front sprocket that is less likely to drop a chain to go with a 7sp freewheel set up hub motor.

Apparently, all the Narrow Wide sprockets are set up only for 9sp and up chains at 1.78 - 1.6mm sprocket thickness. Too thin of a chain to run on a 7sp freewheel with 1.85mm thick sprockets.

I don't even want to get into shifter selection with differences of 5, 4.8, 4.34, and 3.95mm spacing. That should be easy enough if matching components are used. The big question is about where to find the sprocket or crankset with the long teeth to fit a 7sp freewheel.

Or am I worrying about chain drop for no reason? All I want is a single sprocket up front to clean up the bars for the thumb throttle on the left side, and don't need a 2 or 3 sprocket crank setup. I don't want to use a guide either.

Any options?

PS, Also, I'm looking for larger sizes than what I've been able to find. I think 38 is the largest NW option. Looking to use same set up for 700c and 26" wheels, so the larger option would be nice.

 

[DukeMoto]

Something with a tooth pattern like the Luna Mighty Mini.
http://lunacycle.com/parts/bafang-parts/bbshd-parts/luna-mighty-mini-30-tooth-bbshd-chain-ring/

 

[DukeMoto]

Or the AB NW. http://www.chainreactioncycles.com/us/en/black-by-absoluteblack-narrow-wide-oval-single-chainring/rp-prod131089?gs=1&gclid=CjwKEAjwsuK_BRDD9ISR1bawwUwSJACbOiixYQrwJxIgTZpOHSiso0WOm6fLQyUSC-jePy4-a6-uPBoC3e_w_wcB&gclsrc=aw.ds

 

[DukeMoto]

Or, is there a problem running a bigger chain on a thinner sprocket? I imagine the sprocket would have a shorter life since it would be aluminum.

 

[Chalo]

You're overthinking this. 5, 6, 7, 8 speed chains ride just fine on narrower 9, 10, 11 speed sprockets. The other way doesn't work. It's the "cool" new stuff that is functionally impaired.

P.S. - Narrow-wide rings are a gimmick that doesn't work nearly as well as chain guides such as those used on cyclocross bikes since the '50s. In another fifteen years, narrow-wide will be forgotten but actual guide rings will still be with us.

 

[DukeMoto]

You're overthinking this. 5, 6, 7, 8 speed chains ride just fine on narrower 9, 10, 11 speed sprockets. The other way doesn't work. It's the "cool" new stuff that is functionally impaired.

P.S. - Narrow-wide rings are a gimmick that doesn't work nearly as well as chain guides such as those used on cyclocross bikes since the '50s. In another fifteen years, narrow-wide will be forgotten but actual guide rings will still be with us.

Cool. Thanks!