A quick guide to convert from Beta3 and previous to Beta4

[PiBoSo]

1 ) convert the engine primary ratio from a single value to two gears. For example:
Ratio = 3.04 -> ratio0 = 24, 73

2) tyres data has been moved to the new "tyres" folder. Change the bike CFG to point to it. Several changes are needed, it's better to look at one of the stock bikes for reference.

3) the tyres change also involves the graphics models, so the gfx.cfg file must be updated, too. Again, it's better to look at one of the stock bikes for reference.

4 ) it's possible to add fork offset setting in the "steer" section.

5 ) now settings in "front_suspension" are for a single fork only, and then doubled. This means that spring and damper stiffness must be halved. And the area, too.
If the bike only has one shock ( some scooters, for example ), add "MonoShock = 1" in the "front_suspension" section.

6 ) For classic bikes with dual suspension at the rear, it is possible to set a single spring and damper adding "TwinShock = 1" in the "rear_suspension" section.

7 ) In the GEOM file, collision data must be changed. The new format should be more user friendly until the Bike Editor will be changed to edit it.
Please note that the boxes angles are no more set as slope, but are now degrees.

8 ) The geometry of the rear suspension must be changed. The best option is probably to start copying and pasting from one of the stock bikes, and then editing the points in the Bike Editor.

[PiBoSo]

In the geom file, in addition to the "Linkage Rod Chassis" featured on the stock bikes, it's also possible to set "rsusp_type" to "Classic".
With that, you only need the "shock_chassis" and "shock_swingarm" points.