Mountaintech A arm caster and camber adjustment

[MrChetStuart]

Wondering if owners of the M-tech A arm kits could let me know their experience with initial caster and camber adjustments, specifically, how much variation you've seen when trying to dial it in as part of the final installation process. I'm asking because when I installed the 40+2 kit over the summer, I thought that I had it pretty close (caster between 23/24 and camber around -1). I would get slightly different measurements each time I settled the sled, but they sort of floated around what they should be, give or take. I checked them out again today and I'm at about 25 on caster and +.5 on camber. Maybe the suspension isn't settling the same as it's colder now or something. Going to do some measuring/adjustments tomorrow, not that there's much of a rush with this weather, but was looking for any input from you folks that have these adjustable arms. I contacted Peter already and it seems like I'm on the right track, just looking for anything you guys might think is helpful/important. Thanks!

 

[grizztracks]

It's tough to read exact numbers because there are to many variables. My initial setup was done by taking readings with a dial angle finder but then I made adjustments 1/2 turn at a time until I found settings I liked. In the end I didn't care what the actual measurements was as long as the adjustments could be made in equal increments.

 

[herndonp]

I have experienced the same thing you have with the camber. Caster seems to stay close. I believe the important thing to remember is ski straight and tie rods disconnected while adjusting camber. You will notice if you have gage on arm and move the ski the camber is changing. Keep as straight as possible and get it close. Then adjust tie rod to fit back in hole and then set toe out.

Pete

 

[birdmayon]

What is the best tool to buy to set caster and camber? I was looking at these on Amazon:
Johnson Level & Tool and Tool 700 Magnetic Angle Locator or
the AccuRemote Digital Electronic Magnetic Angle Gage Level / Protractor / Bevel Gauge

To me, looks like either would work but not sure if one has an advantage over the other.

 

[herndonp]

Either one of these will work. I like the digital as its easier for me to see. I use an 8" piece of angled steel as a base plate for the magnetic digital gage to put on the side or top of spindle. When not using the digital just pull battery and tape the battery to the gage.

 

[birdmayon]

Thanks Pete. Think I'll go digital.

 

[Sledboy]

You can get the iPhone/Android "TiltMeter" application too. I used this and the "AngleFinder" in herndonp's post and both had same readings. I adjusted to MntnTech's specs and never checked it since because the handling improved so much from stock I don't think I would notice any slight changes in caster/camber on these A-Arms.

 

[MrChetStuart]

It's tough to read exact numbers because there are to many variables. My initial setup was done by taking readings with a dial angle finder but then I made adjustments 1/2 turn at a time until I found settings I liked. In the end I didn't care what the actual measurements was as long as the adjustments could be made in equal increments.

What sort of behavior were you focusing on when you made subsequent adjustments? In your particular case, how do you think you ended up with regard to caster/camber settings assuming that 23/24 & -1 is the baseline, respectively?

 

[birdmayon]

I'd be interested in the same info that mrchet is looking for!

 

[grizztracks]

I made the decision to test the Mountaintech arms more out of curiosity rather than an attempt to improve an ill handling sled. My Nytro actually handled really well with the 2008 setup but after suffering significant front end damage I was in need of new a-arms and spindles. Prior to the damage I had discussions with Peter at Mountaintech about a trail a-arm setup and by chance he called me minutes after I wrecked my sled to see if I was interested in testing his prototype arms. I wasn't overly interested in the 2" forward stance but figured it was a good opportunity to see what a fully adjustable caster/camber setup would do.

I initially set the Mountaintech arms to approximately 26 degrees of caster and 1 degrees of negative camber. I held the camber constant and reduced caster in increments down to 19 degrees. I wasn't focusing on any specific behavior but instead wanted to see how the Nytro reacted to change with the forward stance. After going through the full range of adjustment I finally settled on about 21 degrees of caster with 1.5 to 2 degrees of negative camber. With increased caster steering effort became very heavy and the sled had considerable ski lift. With the changes made up front I also found it necessary to make shock adjustments and in doing so found that that the center shock preload seemed to be very sensitive to change with these arms installed. The forward stance made the front end feel narrow which in certain conditions has it's advantages but I thought the steering was a little sluggish on the tighter trails and it may contributed to the increased ski lift I was experiencing. On the rough trails the Mountaintech arms did very well as far as ride and straight line performance which I believe is due to the forward stance and the addition of the spacer between the upper a-arm and spindle.

I've ran my Nytro with the 08 geometry, Hygear's adjustable Slycast upper a-arm, Mountaintech's trail a-arms and now with Yamaha's newer geometry. I don't want to get into all the details of each setup here but will answer questions through private messaging.

 

[MrChetStuart]

Thank you very much for your insights!

 

[birdmayon]

Yes, thanks for the info Grizz. I've got a couple of additional questions that you may be able to help me with, will shoot you a pm.