Bobsled Equipment and Weight Rules

Bobsled Sled Rules: Engineering Within the Limits

The bobsled itself is a marvel of constrained engineering. The International Bobsleigh and Skeleton Federation (IBSF) imposes strict regulations on every dimension, material, and component — ensuring that the competition is decided by piloting skill and push power, not by whichever nation can afford the most advanced wind-tunnel time.

Weight Limits

IBSF mandates maximum combined weights (sled + all crew members):

• Two-person: 390 kg maximum.
• Four-person: 630 kg maximum.
• Monobob (women’s): 247 kg maximum (with standardized sled).

Sleds are weighed before and after each run. The sled alone has maximum weight limits too (e.g., a two-man sled cannot exceed 170 kg without crew). If a crew is underweight, they may add ballast — steel plates bolted securely inside the sled — up to the combined maximum.

Sled Dimensions

Every sled must conform to precise measurements:

• Two-person: maximum length 2.70 m, maximum width 0.67 m.
• Four-person: maximum length 3.80 m, maximum width 0.67 m.
• The sled’s cowling (front fairing) must be within specified height and width parameters.

IBSF inspectors use templates and measuring tools to verify compliance. Sleds that fall outside tolerances are not permitted to race.

Runner (Kufe) Regulations

Runners are the steel blades that contact the ice, and they’re the most regulated component:

• Material: steel, with a specified hardness range.
• Profile: IBSF provides a reference profile (curvature template). Teams polish and prepare runners within these profiles but cannot alter the fundamental shape.
• Temperature: runners are tested before each heat. Any runner temperature exceeding the reference by more than 4°C results in disqualification. This prevents teams from warming runners to create a friction-reducing melt layer.
• Surface treatment: runners may be polished but not chemically or thermally treated beyond IBSF-allowed processes.

Monobob Standardization

The monobob, introduced for women at Beijing 2022, is unique because all athletes use the same IBSF-provided sled. This eliminates the equipment advantage that wealthier nations traditionally enjoy. Athletes may adjust the seat position and runner preparation but cannot modify the sled’s structure, cowling, or fundamental geometry.

This standardization was a deliberate choice to make the event purely about piloting. The result: nations that historically couldn’t afford competitive bobsleds could suddenly contend.

Aerodynamic Restrictions

Sleds must pass aerodynamic checks — the cowling cannot extend beyond specified dimensions, and no additional fairings, wings, or flow devices are permitted. The goal is to prevent an arms race in aerodynamic development that would favor wealthier federations.

Pre-Race Inspections

Before each race day, IBSF officials conduct thorough inspections:

1. Sled weight: without crew, then with crew.
2. Sled dimensions: length, width, height, cowling shape.
3. Runner profile: compared against IBSF templates.
4. Runner temperature: measured and compared to a reference runner stored in controlled conditions.
5. Safety features: handles, bumpers, and crash structures must be intact.

Any infraction results in the team being barred from that heat or disqualified from completed runs.

Equipment Evolution

Despite strict rules, bobsled engineering evolves. Teams invest in computational fluid dynamics, vibration dampening, and runner metallurgy — all within IBSF limits. Germany, long dominant in bobsled, has benefited from industrial partnerships that push the boundaries of what’s permissible. The IBSF periodically updates rules to prevent any single innovation from creating an insurmountable advantage.