How Caster Works
Hello and welcome back to some brand new episodes of kyle engineers. Today we're going to be looking at suspension geometry. There's a very requested subject now specifically. We're going to be looking at caster camber kingpin inclination angle and scrub radius. now these are all different concepts so I'm going to split them up into four different videos. I just like to say that the website modo iq.com has some really good reads on this handling stuff. You definitely go and check that out after here I didn't steal all my material from there if that's what you're asking. I do actually have a lot of experience in this area but I really recommend it for a good solid read. Now today's lesson is going to be on caster. Now you may hear a lot of time my car reviews I talk about
feeling. The steering needs more caster to get that steering way going in other comments, like that same car needs more caster. This is an important one to understand in both what it effects on the handling side and what it effects on the driver feel side so as far as the definition goes casters very simple we take a wheel looking up from the side if this is the front of the car so that's the bonnet comes back cabin and we look at the steering side of things caster is basically the angle around which the wheel assembly pivots with respect to the vertical so that angle there so we incline our angle of rotation so whether that's by picking double a arm pickup points there and there or whether that's by moving our strut top back to here we get an inclination in there and that is what is known as caster now as far as sine commission goes this direction here is known as positive caster and the other way is known as negative caster almost every car you'll find will have positive caster to some degrees common numbers are from around sort of three to six degrees for a road car although Obviously there are outliers this more and less now what does caster actually do or several things the most dominant thing it does is cause the tires camber angle to change as you spin the steering now this means that as you turn into a corner your tie is essentially into a corner like a motorbike and that allows you to get better camber angles and thus get more grip now if you confused about camber you can watch my other videos on that and so by increasing the caster.