Quote Originally Posted by DoubleActing View Post
Hey, I think I know. I'm guessing your drive sprocket is on one of the ends, right? Going one way, the track under the vehicle runs tense. Going the other way, the track will slacken. One or the other swims better. If you can, get a go pro , a case, and a stick and look at what the track is actually doing down there.
Thanks for your insight. In between summer travels I have been reading too many DoD funded reports from the 60s and 70s on improving water propulsion via tracks (relating to the LVTs of Vietnam I presume). The reason I see reverse going slightly faster than forward is due to the idler/sprocket placement in relation to the bow/stern pitch of the vehicle once torque runs through the driveline (there is a considerable torque reaction once the tracks are moving). I also did some further testing and without the bow fenders, at the highest speed the engine could take (about 8mph land, talk about inefficiency in the water!) I would actually go backwards instead of forwards. I think this is because there are 50% more grousers on the return side of the track than the thrust side. As with any project, more time and forethought could have developed a better vehicle with proper bow fenders, side skirting and maybe even a return chute to redirect track return current 180°. It was fun to learn about track machines and the compromises of amphibians during the build and I am glad others enjoyed it as well.

Ohh also website is up with plans/kitset available next week for those with money burning a hole in their pocket.
https://decentmfg.com/
The plans cover a revised vehicle with no walking beam, beefier axle plates, a lowered hull which provides stability in low payload conditions in the water, and a heightened/tailfinned upper hull for more freeboard. It's no Argo or Muddox, but to some it might be a fun & useful winter project.