Rules Desk
National Derby Rallies rules
Navigate NDR's live rules, later updates, division exceptions, and inspection sheets without importing ISBD rules by accident.
NDR HAS ITS OWN STACK
All-American changes are not automatically NDR changes.
NDR uses many ISBD cars and parts, but its rules page expressly says All-American changes do not automatically carry into NDR. Start at NDR's live rules hub, then read the Common Rule Book, General Car Rules, differences sheet, later page updates, and the current Nationals inspection sheet for the exact class.
An unlisted construction variation requires approval from NDR's chief inspector well before competition. Cars must remain inspectable and, in the main kit classes, readily disassemblable.
DIVISION SNAPSHOT
Current public wording differs from some older PDFs.
| NDR division | Current website age wording | Z-Glas maximum | 2025 tail differential |
|---|---|---|---|
| Stock | 7 until 14th birthday | 200 lb | 5 lb |
| Super Stock | 7 until 22nd birthday | 240 lb | 15 lb |
| Flat Masters | 10 until 22nd birthday | 255 lb | 5 lb |
| Roundbottom / Glass Wrap | 10+, no stated maximum age | 265 lb | 5 lb |
| Legacy | 12+, no stated maximum age | Current inspection sheet calls for 273-275 lb | 15 lb |
NDR Nationals permits an additional ten pounds when its specified aluminum-wheel bank is used in the listed divisions. Read the current event documents for that option.
CONFLICT WATCH
Later guidance and old PDFs do not always agree.
- The January 2022 Common Rule Book states a 7.5-pound tail differential for all divisions; the live page's 2025 change lists 5 or 15 pounds by division.
- Age wording for Stock and Legacy differs among the About page, Common Rule Book, and differences PDF.
- Pre-bow language differs among the differences sheet, General Car Rules, and newer inspection sheets.
Use the later live-page values as the current public signal, but do not silently resolve an official conflict in the garage. Send the exact car, division, event, and disputed paragraph to NDR or the chief inspector and retain the answer.
This site deliberately keeps ISBD and NDR numbers in separate tables. Never move a tail-weight, age, axle, wheel, or construction allowance from one organization into the other.
SOURCES & FURTHER READING
Check the primary material.
- National Derby Rallies rules hub Official NDR landing page, 2025 tail-weight update, rule books, and inspection links.
- NDR divisions and program overview Official NDR descriptions for Stock, Super Stock, Masters, Roundbottom, and Legacy.
- NDR Common Rule Book, January 2022 Official NDR PDF. Some values are superseded or contradicted by later material on the rules page.
- NDR General Car Rules, January 2022 Official detailed construction and inspection rules for NDR divisions.
- NDR and All-American rule differences Official NDR comparison sheet. Verify older wording against current event guidance.
- NDR Nationals inspection sheets Current division inspection sheets are a practical pre-race checklist.