The legions of Michael Schumacher's German fans have been going through a painful withdrawal process since the seven-times world champion retired in October.

Four new books about Schumacher published since their hero hung up his Ferrari crash helmet after a scintillating final drive in Brazil at the end of the 2006 season are making the transition to the post-Schumi era a bit less painful.

While many of the details of his 16-year Formula One career, record-setting seven championships and 91 Grand Prix wins are well known, the books nevertheless offer illuminating insights about Schumacher and his decision to go out as one of the best.

"I kept having to push myself to tests or appointments that I didn't really want to be going to any more," Schumacher reveals with unusual candour in "Michael Schumacher" by Sabine Kehm about his flagging interest in 2006.

The book by Kehm, his press spokeswoman and confidant for eight years, is easily the best of the bunch.

The three others are: "Michael Schumacher - The end of an era" by Karin Sturm; "King Schumi - His Life, His Victories, His Tears" by Helmut Uhl; and "Thanks Schumi! The Michael Schumacher Story" by Willy Knupp.

While pictures and behind-the-scenes images are a central element of all four books Kehm's fascinating narrative is hard to put down.

"I'm not talking about the races or the race weekend work. I'm talking about all the other stuff...the everyday work," Schumacher tells Kehm, explaining in depth his growing fatigue and the origins of his decision to quit last year at 37.

BORING TRAINING

"I always had to go all out in testing. That's the only way to make progress. But going to the limit all the time begins to erode your strength.

"After Bahrain, Malaysia and Australia, I started asking myself how I had managed to keep it up in all the years in the past. I often counted the minutes until I could go home. I don't know if that's the normal wear and tear but tests all year long really wore me down. I was exhausted, more so than in the past."

He said that he realised he "didn't have the motivation any more" for all the preparations needed and bemoaned "training methods that bore you to death".

Schumacher revealed he began leaning towards quitting just before the first 2006 race in Bahrain -- after equalling Ayrton Senna's record of 65 pole positions.

"I always got very emotional when confronted with the history of Ayrton," said Schumacher. "Obviously you don't want to admit that and you try to hide your emotions so you don't show the others you're vulnerable.

"But it happened and I knew we would have a good season, and I had the feeling that now would be a good point to retire. After that it felt more and more like the right decision."

Schumacher said he told Ferrari team manager Jean Todt after Bahrain that he wanted to quit. He said Todt accepted it but told him to think about it for a while. Later, Ferrari said the announcement had to wait until September.

"I personally would have preferred to have announced it sooner, but Ferrari traditionally does that sort of thing at Monza," he said. "I didn't have any problem with that...At least I wouldn't have to keep saying ridiculous things or evade questions."

GRUFF COOLNESS

Schumacher said he was glad he stepped out while journalists and fans were "still asking 'But why now?' rather than 'Why is he still driving? He's too old and too slow'." In the end he was surprised how easy it was to tell the world he was quitting.

Kehm portrays Schumacher as a sensitive and shy man. She said his awkward attempts early in his career to conceal and overcome his aversion to the spotlight with a "gruff coolness" made him appear "pig-headed, aggressive, and unfriendly".

"Every time he's appears in public he has to overcome his inner self," she writes. "He's reserved and never wants to be at the centre of attention. But he also doesn't want anyone to notice his lack of confidence."

Kehm said Schumacher always struggled with fan adulation and recalls how upset he was when a small boy burst into tears as he was about to get an autograph. Kehm said Schumacher was "deeply shaken", stroked the boy's hair quickly and ran back to his trailer to sit down and regain his composure.

"It hurt him when people called him a machine, a robot or a computer even though he would never admit it," she wrote. "He's in essence a sensitive...and introverted man."

The books by Uhl and Knupp are fact-filled tributes for adoring fans. Uhl has come up with some interesting statistics:

Schumacher spent a total of 5.6 years on the road, away from his family, testing, racing and at sponsor events. He drove 361,500 kilometres in Formula One cars in tests and races, burning 252,000 litres of fuel and 15,800 tyres.