pic: 6CIM WCD

[DampRobot]

Originally Posted by Chris is me

Rivets and gussets are definitely both rigid and adequately strong for this application. I don't understand where you're getting rivets with enough play that you can't hold a frame together with them.

We used overly thick 1/8" gussets and a 1/16" solid belly pan this year instead of welding. Chassis was just as rigid, really. No noticeable performance or strength difference at all. Welding is not mandatory for this kind of drive. And there is definitely no need to do *both* permanently.

Here's a picture of our setup. The thickness of the gusset and the number of rivets used were both excessive, but rivets are almost "free" in terms of weight.

I was less thinking of rigidity after the rivets are installed, and more before. When a rivet is first placed in a hole (but not installed) the two pieces being joined together can still move in respect to each other a small amount. 3/16" nominal rivets are designed to go into #10 (.194") holes. While the OD of the rivet is probably larger than .1875" exactly, there is still some play between the rivet and the hole when it hasn't been crushed yet.

Rivets are rigid enough to hold drivetrains together, no problem, just as you said. We riveted (and didn't weld) parts of our drivetrain together this year and the year before. After the rivets were installed, the drive was quite rigid. However, I definitely noticed a significant amount of play before the rivets were installed. I do wish I had taken more care to make sure the drive was square, as rivets aren't perfect for locating frame members together. A bellypan certainly would have helped with getting everything square before the rivets were installed.

Riveting with a bellypan is probably perfectly square, strong and rigid. But, if the OP has TIG and MIG welders in house, why not learn to use them in the offseason?

Just like I said before, it's perfectly fine to completely disregard my (or anyone else's) advice on CD. Personal experience and experimenting in the offseason should always trump what someone says on this forum.