* NOTE Formula RD is a national  WERA class held at selected USCRA events and not a USCRA class.  Formula RD is not eligible for USCRA class championship or Am/Can races.

Formula RD is a "Spec" class formed in the interest of low cost roadracing competition. Eligible machines include ALL air-cooled Yamaha RD350's and RD400's sold in the United States from 1973-1979. Later model RD/LC's, RZ's and R 5's are prohibited. Any Parts ever sold as OEM equipment on a 1973-1979 RD250, 350 or 400 are legal for use on any year or model RD. updating and backdating are permitted. All modifications must be performed in a workmanlike manner and should keep within the spirit of the class. with that in mind, there will be NO titanium or carbon fiber (reed petals excepted), no quick shifters, on board lap timers, or tire warmers. The most important thing to remember is that the rules have been written in the interest of increased longevity and decreased operating expenses. NOTE: The term stock means as sold by the manufacturer with no metal removal whatsoever unless otherwise explained.

1. Air Filters: stock airbox with filter or individual filters permitted, no open carbs or stacks
2. Battery: unrestricted, must be securely mounted 
3. Carburetors: stock, no overbores or polishing, jetting changes Permitted 
4. Cases/Connecting: stock
5. Charging System: may be disabled or removed
6. Clutch: stock, aftermarket friction plates and springs permitted
7. Crankshaft: stock, may be welded, stroking or balancing prohibited
8. Cylinders: stock, mar be overbored (max. 2mm), ported, skimmed, may use equivalent  aftermarket sleeve, pollution controls on RD400F heads may be disabled or removed.
9. Cylinder Heads: stock, may be skimmed to increase cranking pressure, one piece RD400F heads may be cut apart for easier service, reshaping of combustion chambers allowed
10. Expansion Chambers: must have silencers and securely mounted at two or more points, no heat wrapping
11. Fuel: racing gasoline permitted
12. Gaskets: unrestricted
13. Ignition: stock or any electronic Permitted
14. Oil: unrestricted, oil injection may be disabled or discarded
15. Pistons/Rings: stock or equivalent aftermarket
16. Reed Valves: stock cases, aftermarket petals permitted
17. Starting System: kickstarter may be functional but must be removable
18. Transmission: stock, undercutting permitted, no quick shifters
19. Wiring Harness: unrestricted
20. Appearance: Bikes must be clean, painted, and externally oil free at all times
21. Bodywork: May use stock or aftermarket tank, seat. and fenders, no carbon fiber, no fairings
22. Brake Lines: unrestricted, but must be safely routed and secured
23. Cables: Unrestricted
24. Chainguard: unrestricted, may modify, remove, or replace
25. Controls: stock twistgrip throttle must be retained and must snap back to "off" position, "kill" switch must be functional, may change grips and levers
26. Disc Brakes: stock, may be drilled (to help cooling) and/or machined (to eliminate warping), aftermarket pads permitted, brakes must be fully functional
27. Drum Brakes (if applicable), liner may be machined (to eliminate scoring), aftermarket shoes permitted, brakes must be fully functional
28. Footpegs: unrestricted, passenger pegs must be removed, mounting brackets may be removed or replaced (such as using rear sets)
29. Fork: externally stock, may use aftermarket springs and valving , may use fork brace
30. Frame: stock, may use tapered head bearings, removal of unnecessary tabs Permitted, gusseting prohibited
31. Gearing: unrestricted, but must use stock size chain (530)
32. Handlebars: unrestricted, see component Specifications (a).
33. Hardware: replacement hardware must be of like material, no titanium
34. Horn: must be disabled, may be removed
35. Instruments: unrestricted, speedo drive unit may be replaced by spacer, no onboard timers.
36. License Plate, mirrors, side & centerstand: Must be removed
37. Lighting: sealed beam unit must be removed, headlight shell and bracket may be removed, taillight, reflectors, and turn signals must be removed
38. Master Cylinder(s) : Stock, no oversize Pistons
39. Numberplates: Numberplates shall be visible on front and both sides with rider sitting on machine.  can be yellow numberplates with black numbers. 
40. Rear Brake Stay Arm: unrestricted, may be modified or replaced
41. Safety Wiring: All fasteners that retain fluids, all brake caliper mounting bolts, all axles-safety wiring must be done in accordance with the rules per Chapter 8.
42. Shocks; may be replaced, must use stock mounting points
43. Steering Dampers; required, and must be installed in such a way as to not limit handlebar travel (i.e.) steering stops must contact before damper bottoms or tops out)
44. Swingarm: stock, may use aftermarket bushings or bearings, gusseting prohibited
45. Tires: must be street legal (D.O.T. approved) and fitted With tubes, must safely fit wheels, tire warmers prohibited
46. Triple Clamps: stock, must retain steering stops to prevent handlebars from contacting tank, may be built up for this purpose
47. Wheels: stock, must use factory cast or spoked wheels, no aftermarket rims metal valve stem caps must be used

Table of Contents (click on any item to view that page)
Names and Addresses
Class Overview
Bumping
Rule Changes
Championship Points
General Rules
Early Vintage & Pre '65
Screaming 50's
Grand Prix (Period I)
Supervintage (Period II)
Middleweight (Period III)
Period IV
Formula RD
Formula CB350
Sidecars
American Twins