SFI 16.1 and 16.5 Seatbelt Standards

Laurie Callender Seatbelts

There are 4 different SFi standards for seat belts, 16.1, 16.2, 16.5 and 16.6 and currently the rules in most forms of NZ motorsport allow approved SFI belts with either a 16.1 or 16.5 rating. So, what is the difference with these two belts?

Both Standards allow for the same size belt widths (Min 44mm (1.72”)) but the 16.5 belts have a higher breaking strain along with  heavier duty hardware. Both of these standards have a maximum of two years life span on the belts. This is mainly due to the Nylon Webbing deteriorating with UV sunlight, dirt and water etc in our environment and will lose 75% of its original tensile strength after 30 months.

The 16.1 belts are labelled with expiry dates on the LH Shoulder and LH Lap belt as well as the ant-submarine belt, three in total. The 16.5 belts have conformance/expiry labels on all belts.

On 16.5 belts the standard allows wrap around mountings on shoulder belts that do not cross behind the driver’s seat and on the ant-submarine belt only. The lap belts must be mounted with a swivel mount or eye bolt and clip to ensure the correct seat belt angle is achieved.

The 16.1 belts do not have this same mounting requirement however it is highly recommended not to use wrap around mountings for the lap belts as it is almost impossible to achieve the correct lap belt angle of 45 to 60 degrees from the pelvic area. The picture below shows an open wheel lap belt which is not only wrapped loosely around the chassis rail, it also does not allow the correct seat belt angle.

Wrap around lap belt

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