A-Arms for the Yamaha SR Viper use the Arctic Cat ProClimb Front End
Go to: http://www.skinzprotectivegear.com/snowmobileproductad/aarmsforarcticcat.html
Here are some of the details of the Concept front end for the Viper/AC:
4130 Chromoly upper and lower arms
37" and 42" widths available
3" + Forward Spindle Placement
-increases predictablitly in cornering and over rough terrain
-improved stability, creating a larger "range of balance" when the sled is on it's side but eliminating diving and off camber rollover.
-transfers weight to the rear suspension, decreasing rider effort
New caster angle for improved tracking and counter steer
Ride height adjust-two lower shock positions allow the rider to choose a different ride height. Perfect for 3" track applications where ride height needs to be increased.
Shorter billet aluminum spindle
-minimizes drag in snow
-changes upper and lower a-arm spacing to minimize camber gain
-moves ski mount inline with upper/lower a-arm to sharpen steering
-adjustable steering mount allows for fine tuning bump steer
