rake angle/caster of forks

[gene]

what rake angle do you want when assembling a basic minibike frame? or how much positive caster do you want? thanks Gene

 

[Charles S]

Look at motorcycle forks, around 22 degrees rake minimum for very agile sportbikes with a steering dampener to make it controllable, around 35 degrees maximum for cruisers/factory choppers to be very stable. I don't remember 'caster' being used regarding motorcycle forks, there is 'offset' with the axle usually being offset forward of a straight line projected through the steering head. Offset is usually obtained in the triple clamps, locating the fork tubes forward of the steering head. There is also 'trail' which pertains to the contact patch in relationship to a line projected through the axle and parallel to the steering head. For a minibike, which tend to be a bit unstable due to a short wheelbase and other factors, I think I'd go for around a 30 degree rake with 1-2" of offset but it depends on what type of handling you want.

https://en.wikipedia.org/wiki/Motorcycle_fork

https://en.wikipedia.org/wiki/Motorcycle_suspension

 

[Minimichael]

Pure gold, Charles. Thank you.

 

[gene]

Application is just a general purpose minibike to be used a street and some dirt . Thanks

 

[Mariah]

When I build frames my goal is to have 26 degrees of rake and 3 inches of trail. They steer pretty well with 10" wheels. If you Google a bit you can find motorcycle articles that explain these measurements with pictures to show how the measurements are checked.

 

[SAT]

We fab to Mariah’s specs above. Tack things enough to hold, mount the wheels and push it around the driveway long enough to know, either way.