I purchased a Motobecane Team Track:
It says it has the following:
Crank - Shimano Dura Ace 49T Aluminum Track ring (3/32 width)
Chain - KMC Z410 (3/32 width)
So I purchased a 3/32 chain whip for the cog and would not fit. I had to return it and purchased a 1/8 chain whip for the cog and works great.
The website did not specify the cog width but i assume you cannot mix and match 3/32 crank/chain and 1/8 cog.
Can you determine what I have from these pictures that i've taken?