Hello Lorenz

No, I don't know.
But ... you should be able to calculate it by doing this ...

The theory is that on the highest height setting, the tip of the front blade should
be no more than a couple of degrees lower than the same measurement at the back.
This is a positive angle of attack. This would mean, at any height setting,
the tip of the front blade will always be lower.

Too large a diameter of front wheel will result in a negative angle.
That should be avoided. This studio shot depicts front wheels at highest setting.
Note how the blade holder appears horizontal.
Also note that the top of the front wheel is about equal to the radius bend
of the wheel bracket.

[Linked Image]

Hope this helps.
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Jack