The bumper rules say the biggest allowable gap between the bumper and the frame is 1/4’’. On our kit chassis we are unsure if we need to worry about this gap around the wheels. See the attached picture. :]
Check out R26.
It’s more than 1/4" deep, but less than 8" across. You’re good to go.
In part C of the same rule: “the BUMPER must be backed by the FRAME PERIMETER at least every 8 in.” allows this space to be open on the frame. The space in question could not be greater than 8", for then it would not be possible to back the bumper by the frame as prescribed.
If memory serves, this space is between 3 and 4 inches.
Per R26,
Additionally, any gap between the backing material and the frame
A. must not be greater than ¼ in. deep, or
B. not more than 8 in. wide.
You can have a gap deeper than 1/4", so long as it is less than 8" wide along the frame perimeter. The way the kitbot is assembled, the gaps you pointed out there are perfectly legal, as they are less than 8" wide.
Well, as also per R26, “a minimum of ½ in. at each end of the BUMPER must be backed by the FRAME PERIMETER.” Is that end of the bumper backed by the Frame Perimeter for at least 1/2 in.?
A. When assembled according to the instructions the AM14U KOP chassis has a 5/8 in. flange extending inward from the outside plate inside the BUMPER ZONE which may be used to satisfy R26.
Why wouldn’t you want to wrap the entire perimeter? Gaps allow for things to stick in there where they don’t belong and wreak havoc, no?
please read this post
as it is along the same idea.
The gap between is fine but you to be supported by the outer side rail.