I have had my FULLFLIGHT a arms for about a year now and just recently adjusted the caster. I thought when i bought them they were ready to install so i never attempted to set it. Well after i started riding my friends LTR i realized my Z didnt handle nearly as well as his LTR, so i set out to find the problem. At first i thought that it was because i have a +1 forward style a arm set up. So i looked into that and found that Gust was running a similar setup, +1 up front and +2 in the back, (he ended running +1.5 on the front) but anyway i just figured that wasnt the problem. Then i thought it was my tires, but i rode a friends cannondale with bald tires on the front and it handled better than mine so i knew that wasnt the problem. So i started looking on here for some more info and found some articles on caster adjustment. there were no really detailed posts just a little info here so i asked drnez about it gave me a little info and i did some searches on google and this is the info i found. Caster is angle of the top ball joint or heim joint in relation to the bottom one. It has to be between a 4 and 5 degree angle (for MX). Here is what i did step by step to find the angel it was originially set at it and how i set it to the proper angle. STEP 1 First i took a motorcycle jack and put it under the quad to the height it is when i am sitting on it. then i removed the front shocks.
STEP 2 After i had the front shocks removed, i could then measure the angle the joints were at. I took and old straight tie rod as my straight edge, a small level and a angle finder (contractors protractor).
I took the tie rod and ran it along the inside of the top and bottom heim threads. then i took the angle finder and ran it along side the tie rod. after i had those steps done i had my friend hold the level on top of the angle finder untill it was level. All of that gave me my angle of 11 degrees.
It was originally at an 11 degree angle which was way off from where it was supposed to be, so i knew i found the reason it was handleing so bad. So i took the top a arm off on the side that it is mounted to the frame.
Once i had it off i screwed both of the heims all of the way in as far as they would go and still mount up to the frame.
then i started turning the back heim out. janssens website said to start with three turns and go from there so that is what i did. I mounted it back up and measured the angle again (STEP 2 Pic 2). it was still too much of an angle so i turned it out 3 more times for a total of six full turns. So i mounted it back to the frame once again and measured it and it cam out to be exactly 4.5 degrees.
Once all of that is done move on to the next side and repeat the steps. After both sides are set at the proper angle you will need to set the toe of the tires and the camber. the tires should be toed in between 1/8 and 1/4 inch. To adjust the camber you use the same method for finding the angle of the tire as you do for finding the angle of the heims. set the tie rod on the out side of the tire, run the angle finder along it and then use the level to find the angle. You the adjust the top large heim in or out untill it gets the wheel to the angle that is desired. it needs to be a 4 degree angle as well (for MX). Once all three things are set put the shocks back on, take it off of the stand and your ready to ride.
I hope this is easy to understand for everyone. I had no idea how much better the quad would handle with the caster set right. It was a night and day difference. So if you have never done this or did not do it right i would suggest doing it because it will make riding a lot more fun and it will be easier to ride. you wont have to make it turn anymore it will trun easily on its own, and turn on a dime. Also here a link to jannsens website. it gives you all of the angles for caster and camber for different styles of riding like Motocross, Cross Country, Sand Dunning, Desert Racing and Recreational Riding. It will also give you some other useful info for setting up the front end of your quad... http://janssenmotorsports.com/tech_article...cle&artid=9