California's Highway Design Manual which designers of the highways in California must adhere to has the following:

quote:

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Topic 203 - Horizontal Alignment

203.1 General Controls

Horizontal alignment should provide for safe and continuous operation at a uniform design speed for substantial lengths of highway. The standards which follow apply to curvature on both 2-lane and multilane highways except when otherwise noted. These standards also apply to portions of local streets and roads within the State right of way which connect directly to a freeway or expressway, or are expected to do so in the foreseeable future. For local facilities which are within the State right of way and where there is no connection or the connection is to a non-controlled access facility (conventional highway), AASHTO standards shall prevail. If the local agency having jurisdiction over the local facility in question maintains standards that exceed AASHTO standards, then the local agency standards should prevail. design speed.

203.2 Standards for Curvature

Table 203.2 shall be the minimum radius of curve for specific design speeds. This table is based upon speed alone; it ignores the sight distance factor. If the minimum radius indicated in Table 203.2 does not provide the desired lateral clearance to an obstruction, Figure 201.6 shall govern.

Every effort should be made to exceed minimum values, and such minimum radii should be used only when the cost or other adverse effects of realizing a higher standard are inconsistent with the benefits.

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The following table shows the standards in the Table 203.2 mentioned above and the lean angles necessary for motorcycles to negotiate curves conforming to the standards:

Standards for Curve Radius in California and Required Lean Angles

Design Speed		Minimum Radius of Curve		Lean Angle
km/h	mph	m	yard	degrees
30	19	40	44	10.0
40	25	70	77	10.2
50	31	100	109	11.1
60	37	150	164	10.7
70	43	200	219	10.9
80	50	260	284	11.0
90	56	320	350	11.3
100	62	400	438	11.1
110	68	600	656	9.0
120	75	900	985	7.2
130	81	1200	1313	6.3

(Design Speed in mph and Minimum Radius of Curve in m are from the Table 203.2 of Highway Design Manual for the state of California. Others are by me.)

If we ride within speed limits on California's highways, we shouldn't have to lean our bikes much more than 11 degrees from the vertical.

Pretty tame, don't you think?