John Surtees, only person to win both the 2 wheel world championship and the 4 wheel world championship, and as I've heard it, shamed Moss in several vehicles at several tracks with better times, has gone on ahead.

I sure as hell can't do as good of a job writing what a great champion or significant racer he was as Motor Sport Magazine, and since they've already set the standard, just head over to http://www.motorsportmagazine.com/opinion/f1/john-surtees-1934-2017 if you've thought it a good idea to learn more about one of the most impressive guys to ever lap a track

The love of racing never left him. 
Late fatherhood – Henry Surtees was born in 1991 – gave John the opportunity to get involved all over again and together the pair rose through the karting ranks. 
They were close and Henry was gifted. 
Tragically he lost his life to a bouncing wheel in the 2009 Brands Hatch F2 race. 

It cannot even be comprehended how it felt at 75 years old to lose an 18-year-old son. 

But he didn’t just curl up and surrender. John’s strength of character shone through yet again in his establishing the Henry Surtees Foundation, a charity to assist those with accident injuries.

It doesn’t seem he has been given proper due of how a great driver he actually was.

As a rider, one has only to look at the percentage of races won to settle the matter for ever.

He was one of the very, very few to be on level terms with Clark, without having the luxury of a works Lotus or Brabham.

 He won GPs with three different makes, of which the penultimate one for a declining Cooper and the first ever for Honda, which says a lot.

I believe he has the record of most wins in non-championship F1 races, in the era when those were still competitive.

His two wins at the ‘Ring add a further dimension, not to mention his many wins in prototypes.

His engineering  acumen as designer and constructor contributed to his F2 championship,

http://www.motorsportmagazine.com/opinion/f1/john-surtees-1934-2017