By Alan Baldwin
HOCKENHEIM, Germany, July 19 (Reuters) - Lewis Hamilton's German Grand Prix qualifying crash put Formula One's brake suppliers in the spotlight on Saturday after Mercedes raised safety concerns about the discs used by the Briton.
The incident also showed how sensitive individual drivers are to subtle differences in rival products and how much chopping and changing goes on behind the scenes over a race weekend.
Mercedes blamed Hamilton's accident on the failure of a new right front brake disc manufactured by Italian company Brembo.
The Briton's team mate and championship leader Nico Rosberg, who qualified on pole, was using different front discs after opting for a type supplied by French manufacturer Carbon Industrie.
Mercedes motorsport head Toto Wolff said it was normal practice for drivers to switch between suppliers according to circuit characteristics and their individual styles of driving.
"They play around all weekend with it," he said.
However, he also indicated Hamilton would have to change to the same brand as Rosberg for Sunday's race as a precaution because there was insufficient time for Brembo to carry out technical checks.
Wolff said Mercedes had suffered a similar Brembo failure in testing in Barcelona earlier in the year on Rosberg's car, after which the supplier had upgraded the product.
The Austrian suggested the fresh failure, which left Hamilton unhurt but facing a hard drive through the field on Sunday, could have implications for rival teams.
"We have had a brake failure which means we are obliged to make sure the car runs safely on Sunday," he said. "Many teams run that brake material, so that safety discussion maybe needs to be extended."
Hamilton said he had used discs from all three Formula One suppliers - the other being U.S.-based Hitco - in his time and preferred the Brembo ones because they suited his more aggressive style.
"There's so many different brake materials around and when you hit the brake pedal you want to have a lot of bite," he explained. "You want to make sure that when you do hit them (the brakes), and you hit them hard, they have as much stopping power as possible without locking up.
"From circuit to circuit, whether the track's really grippy or not, you can actually choose the brake that perhaps doesn't bite as much at the beginning but has more bite later on, or has less fade," he added.
"I chose these ones because they had more stopping power which means I can brake later."
Rosberg told reporters the car's brakes were one of the areas he had not been 100 percent happy with and he had experimented with different kinds this season.
"It's been an ongoing process," he said. "Every other weekend trying different things, we try and do back-to-backs wherever possible of various things...and then I always go with what I feel most comfortable with."
Rosberg said the difference between the brands was subtle but important.
"It's a lot to do with feel and comfort, not absolute performance," he said. "There's also that, but a lot of it is comfort." (Reporting by Alan Baldwin; Editing by Rex Gowar)