SAE J1232-2000 pdf download Passenger and Light Truck Tire Traction Device Profile Determination and Classification
Scope-The purpose of this SAE Recommended Practice is to set up a guide as to body, frame, andwheelhouse clearances required to accommodate tire traction devices (e.g, tire chains), and to provide ameans of classifying these devices according to their maximum profile. ln addition, it enables the vehiclemanufacturer to specify the proper traction devices for each vehicle.
This report is intended to apply to passenger cars and light trucks up to 4535 kg (10 001 lb) GVW. Thisdocument is not to be construed as approving traction device operation at conditions exceedingmanufacturer’s specifications, although short periods of such operations may be required for test purposes.
References_There are no referenced publications specified herein.
Test Vehicle-Passenger car or light truck capable of running a tire of a size recommended by the tractiondevice manufacturer for the size of a traction device under consideration. A light truck with rear fenders anobed removed is a convenient test vehicle. Static vertical load on the tire shall be from 85 to 95% of the testtire’s T&RA (Tire and Rim Association) load at 180 kPa (26 psig) cold, or vehicle manufacturer’srecommendations. All road testing should be conducted on smooth, hard surfaced roads.
Profile Measurement (Method 1)-A means of measuring the dynamic profile of the traction device and tiremust be provided. high speed (500 frames per second minimum) motion picture camera has provensatisfactory. The center of the lens system should be placed on the intersection axis of a maximum sidewalplane and a plane normal to the sidewall plane containing the maximum tire radius (point C, Figure 1). Thecamera may be pivoted about the lens center to show a profile view of at least the sidewall, half the tread, andthe traction device. Appropriate measurement scales should appear in the framing for scaling the fly-offThese scales should be in the radial tire plane incorporating the tire section of interest, Generally, the largestprofile will be obtained at the rear of the tire. Figure 2 shows a typical test setup.
Profile Measurement (Method 2)-An alternate method involves moving guided abradable material (e.g., a25 mm (1 in) thick plank of 2.4 to 3.2 kg/m% (1.5 to 2 lb/t3) rigid polyurethane foam) into the rotating tireagainst a stop. The quides become part of the unsprung mass and must be rigidly attached to the axlesupport. After being sculptured by the traction device, the running clearance can be measured statically.Figure 3 shows a typical test setup.
Traction Device Installation- -AlI traction devices shall be new or with less than 5 km operation. Traction devices should be installed to the same degree of fit that can reasonably be expected in the field. The following procedures are designed to accomplish this. Deflation or tools not furnished by the device or vehicle manufacturer are not allowed. Before installing, lay the traction device flat and remove any twists or kinks.