I put the clam extension on my clam gear drive using a 8 inch Mora Strike Master auger bit. I attached the auger to the Clam extension using the included hex bolt and used the auger wing bolt to attach to the gear drive. Likely had that backwards as it failed after about 40 holes and my bite went down the hole after the bolt broke at the gear drive.
Anyhow I noticed that the Mora drags you down to the ice when you break through and that if you aren't on that it is tough on the back. Since I am back to square one pairing the Clam gear drive with another auger bit and do not wish to add more structure to the lake, any ideas on what auger bit works best with this application. By the way the gear drive drill 8 inch hole easily and I never found the end of the battery on my fuel drill.