Kadee 552 | A.S.F.® Ride Control® 50 Ton Self Centering Trucks with 33" Smooth Back Wheels - Metal Fully Sprung (HO Scale)

#552 A.S.F.® Ride Control® 50 Ton Self Centering Trucks with 33" Smooth Back Wheels - HO Scale Metal Fully Sprung Equalized Trucks Mounts with Kadee Self Centering bushing on a flat surface with a #2 or 2-56 screw or without the Kadee Self Centering bushing on a 0.140" or smaller molded on truck post secured with the original screw. The A.S.F.® A-3 Ride Control® 50-ton freight truck was introduced in the 1940's and is one of the forerunners of modern freight trucks. Features embodied into this design include a longer spring travel, no spring planks and constant friction control using friction castings in the bolster to dampen excessive lateral roll of the car. These design features allowed for a higher train speed with less danger of derailment than previous designs. ASF® sold over 140,000 sets by 1949. This truck is excellent for modeling the transition era up to 1994 when friction bearings were no longer allowed in interchange service. The Bettendorf Double Truss Truck was introduced in the 1930's by U.S. railroads and was allowed to be used in interchange service through 1993. The Kadee® #500, #502 & #550 represent 50- ton trucks for 100,000 pound cars. HO-Scale Metal Fully Sprung Trucks Features:  Self Centering Action - Trucks self align themselves parallel with the car for easier placement on track. Code 110 (.110) #520 33" Smooth Back Wheels #441 Brake Pads - Narrow Bolster Accurate Markings Incredible Detail True to Prototype Non-Magnetic Metal Wheels Highly Flexible Sprung Trucks Metal Sideframes & Fully Sprung Self Centering Bolster Smooth tracking Free Rolling Contoured Insulated Plastic Axles RP-25 Free Rolling Wheels #637 HO Scale Truck Springs Patent number 5,768,999 Package Includes: (2) Each #552 A.S.F.® Ride Control® 50 Ton Self Centering Trucks (assembled) (2) #441 Brake Pads - Narrow Bolster (2) Each Self Centering Bushing (2) Each #2 Screw The term Code 110 and Code 88 relates to the width of the wheels and has no relationship to track code. Code 110 wheels are .110" wide and Code 88 are .088" wide. Code 110 wheels are the common (or "Standard") width wheels and Code 88 are what is called "Semi-Scale" and are used when the modeler wants a more prototypical looking wheel width. Actual HO-Scale prototypical wheel width would be around .067" wide and although they will run OK on the average track they will not go through common turnouts and crossings. Code 88 (.088") is just about the minimum width of wheel that will run on most standard or common track if gauged correctly. It really is a matter of appearances because there's very little operational differences between running Code 110 or Code 88 wheels. Code 88 wheels look really good and are most noticeable on open frame cars like hoppers and tank cars. However, they also look great on boxcars, gondolas, and reefers but not quite as noticeable. As mentioned above track code and wheel code have no relationship meaning Code 110 and Code 88 will run on most any code of track. Track code is simply the measured height of the rail, code 100 is .100" tall, code 83 is .083" tall, code 70 is .070" tall, and so on.