Adidas, Gilbert balls don't meet IRB specifications, study finds

The Adidas rugby balls used by the All Blacks in the home tests this season do not meet International Rugby Board specifications, a Canterbury University study has found.

University researchers investigated the dimensions of the Adidas and Gilbert rugby balls and concluded both balls were heavier and smaller than International Rugby Board specifications.

Researcher Dr David Aitchison said it was impossible for either ball to be "legal" using the current type of material and style of construction.

All Blacks goalkicker Andrew Mehrtrens compared the Adidas ball to a "dead pig" after the first Irish test, earning him a reprimand from the New Zealand Rugby Football Union (NZRFU).

However, it seems Mehrtens' comments were justified, according to the university study.

The balls were videoed, analysed, tested and measured for weight and bounce and were trialed in an engineering department wind tunnel.

"The purpose of the testing wasn't to see whether one ball was better than the other. It was to record significant differences and consider how this might impact on their performance," Dr Aitchison said today.

The Adidas ball was 17 grams heavier than the Gilbert and also bigger. They also differed in the amount of bounce, with the Gilbert showing the potential to a slightly higher bounce, although the result needed to be tested more rigorously, Dr Aitchison said.

Adidas is in the third year of its five-year multi-million dollar sponsorship deal with the NZRFU.

One of the requirements of the contract is to use the Adidas ball in the NPC and international matches played in New Zealand.

The Gilbert ball is used in New Zealand-based Super 12 games.

- NZPA