caster & camber

[kpwilburn]

Could someone please explain this to me? What exactly is caster & camber?

[MX26]

Good question.

Camber: The angle between your tire and the ground. I learned alot about this when I bought my LSR a-arms. Most stock quads come with a 90 degree camber.. Meaning that your tires have a right angle with the ground. For a negative camber, the degree must be over 90, and for a positive, they must be under 90. Does that make any sense?

[boogiechile]

Camber is the way your tires lean in or out at the top when looking at them from straight on in the frt. If they are straight up and down or 90 degrees to ground then that is zero camber. Leaning in at the top toward the fenders or frame is negative camber. Camber is measured in degrees so as to say that if the tire leaned in toward the frame at the top by 2 degrees that would be 2 degrees negative camber. Leaning out would be positive camber.

Caster is a relationship of the upper and lower ball joints to a vertical plane or line when viewed from the side of the quad. If you drew a line that passed through the center of each ball joint and then looked at it from the side of the quad it would have zero caster if the line was straight up and down vertical. (90 degrees to the ground) this would be zero degrees caster. If the line leans toward the back at the top then the caster is positive by how ever many degrees the line leans back. The top ball joint would be closer to the rear than the lower ball joint. Negative caster would be the opposite (line leaning toward the frt at the top.)

Positive caster helps your frt end hold its line and makes it easier to stay in control at high speeds when going straight. Negative caster makes it steer quicker and be more agil in turning but takes away stability in holding a line. Drag racers use a lot of positive caster while road racers will go for less caster to quicken steering. For mx on a quad about 4 degrees positive is a good starting point for all around handling.

Camber is used to correct for tire roll over in the corners and can depend on several factors, but mostly on the type of tires you run. for mx the flat tread radial tires will usually need a little more negative camber than the rounded type tires like holeshot mx.

anyone have a pic of a quad with noticible positive and negative caster. I know what it is but im still confused:uhoh:

[Sparks425Ex]

Well put MX26 and Boogie....

Originally posted by QuadMX18
anyone have a pic of a quad with noticible positive and negative caster. I know what it is but im still confused:uhoh:

TT quads have lots of caster changes...Go here http://www.danacreechracing.com/Anaheim2003.htm to see lots of quads setup for TT and some decent close-ups of Dana's walsh A-arm all jacked up from hittin a concrete retaining wall..:eek:

:eek:

[MX26]

Well, I'm glad I didn't go ahead and put what I thought caster was.. I'd feel like a moron now. Here's a pic. The Banshee has around 2 degrees negative camber.

I know they're not even. I just put them on and was trying to get them set before it got dark.

[kpwilburn]

Thanks guys, that was a big help.

[boogiechile]

Yea that banshee is a good example of negative Camber. You really can't "see" Caster however just looking at the quad.

[boogiechile]

One other thing. You cannot adjust Caster unless your a arms use heim joints were they attach to the frame.

[Str8Wicked]

I learned caster camber, etc when I lifted my truck and tried to get it alighned. Since we originally had to re make the upper a arms it was a ***** to get it aligned until I got my new uppers. During that time when aligning I found out what all this meant since we had such a bad time with it.

I figured on my truck the camber was eating up my tires since they were off but we could not get good camber and caster so I had to pick. Caster on a car is what makes your vehicle drift to one side if it is not correct. In a lifted truck it was better to have the truck going straight than the camber perfect and the truck all over the place. Also when you turn your steering wheel on a turn your caster is off if it does not want to return to the straight position by itself.

My 2 cents

[400grl]

I have a little negative camber going on - more noticeable in the left tire at this angle than the right one........

Originally posted by boogiechile
You really can't "see" Caster however just looking at the quad.

ok thanks that was the answer i was looking for:D

Originally posted by boogiechile
One other thing. You cannot adjust Caster unless your a arms use heim joints were they attach to the frame.

so what is the caster on like housers where u cant adjust the caster. 0 degrees?

[boogiechile]

probably about 3 to 4 degrees positive. It is good to ask companies what they set the caster to on the a arms that are not adjustable but nobody seems to know to do that. But then you would need to know what you wanted for it to mean anything. I like a arms that are caster adjustable, I make my own, but if I was buying some I would only consider the caster adjustable ones. Every frame is not the same, especially stock frames that are raced mx. So being able to adjust both caster and camber is a good thing.

[MX26]

Excellent info boogiechile

these a-arms are caster and camber adjustable. the hiems that mount them to the frame is where the adjustment takes place.

http://www.herrmannracing.com/400-EX-long-tavel-up-close.jpg

[Jnine]

Most of the motocross guys set the camber to about 5 degrees. That is, the top of their wheels lean in about 5 degrees. I have seen some riders really overdo the camber and have them leaning WAY in, but that puts a lot of sideload on the bearing & spindle. Too much camber is definitely NOT the hot setup, and when you land off a jump the wheels will lean in even more, creating even greater load on the spindles & bearings.

As for caster, it is possible to alter both caster & camber with some of the A-arms available, so if that is what you have, you will have to watch BOTH angles when you make your adjustments. If your a-arms only allow for camber adjustment, don't sweat it... They're just fine.

[boogiechile]

Good point about adjusting. If you adjust the caster it will change the camber, but adjusting the camber will not change the caster. So the caster needs to be adjusted first if your arms have the adjustment.