[jwfoss]

80/20 is a great material to work with but it does come with some difficulties as well. An option would be to use some flat plate with your axle holes or bearings and mount to the sides on the 80/20 rather than the top of the rails.

If you are not totally set on 80/20 for your chassis, and dont want to spend any extra money, you may want to consider throwing together a 6wd on the kitbot. Integrating an 80/20 superstructure onto a proven chassis has worked for a large number of teams over the years.

There are a number of things that would cause #25 chain to fail. From proper tensioning to misalignment in the sprockets. Be careful with these things, but remember that although it is heavier, #35 chain is also more forgiving.