We get a lot of questions about the weight of our wheels and the relevance of weight to performance and to safety. The weight is important – this is what makes the difference to the unsprung weight. It also matters where the weight is concentrated or reduced in order to affect the performance – the moment of inertia. Safety is critical and the authorities governing this are the JWL and the TUV. Your wheel has to pass the impact tests they define.
Impact Testing – Understanding the Loads
In order to pass either the JWL Impact Test or the German TUV Impact tests, the IMPACT requirements are defined and clear, and must be performed on a test rig defined by JWL:
Front Wheel must withstand the impact from a weight 2.5 times the published Static Load rating.
BST published Static Load rating is 150kg.
Impact weight = 150 x 2.5 = 375kg. The wheel can withstand an impact of 375kg.
Rear Wheel must withstand the impact from a weight 1.5 times the published Static Load rating.
BST published Static Load rating is 250kg.
Impact weight = 250 x 1.5 = 375kg. The wheel can withstand an impact of 375kg.
Check The Facts on the Published Static Load:
Published Static Load of 180kg on a Front Wheel: the strike weight must be 450kg (180 x 2.5).
Published Static Load of 280kg on a Rear Wheel: the strike weight must be 420kg (280 x 1.5).
This is all defined in the JSAE JASO T230 (1985) publication:
The highlighted section is definitive.