Some tips here on inspecting a used chassis:
You can also run a piece of string from the kingpin to the axle along each side and diagonally to gauge the dimensions. Of course the latter can be challenging if the seat is in place.
Both sides should be the same length.
On the diagonal measurement the distance to the point where the two strings meet should be the same distance on both strings.
I’ve found the “placing on the ground” method can be unreliable unless you’re very particular about it…
For the “ground test” to give an accurate representation, some conditions to be met:
- Ground must be VERY even. (Most ground that looks even is far from it)
- Ensure tire circumferences are equal on both sides. (Getting the circumferences equal might require some tweaking with tire pressures outside of normal racing ranges)
- Tires should of course be clean and devoid of “clag”.
- Caster, camber and ride height on both sides on the front should be the same.