Channel 4's recent 'Speed with Guy' documentary follows the story of bike racer Guy Martin spending the Belgian Grand Prix as a working member of Williams Martini Racing. Although this was never the intention, the hour-long programme actually works as a F1 recruiting campaign for prospective fans and employees alike.

They could not have chosen a better candidate; Martin looks like he's walked in from central casting. Here is a fully qualified mechanic willing to see if he's got what it takes to be chosen as a member of the crack pit stop crew.

Having parted company with his bike, frequently at high speed and occasionally on fire, simply pulling off a rear wheel would appear to be child's play to a man of Martin's track record for putting his neck on the line. The documentary scores by convincingly proving otherwise.

The viewer is left in no doubt about the skill and dexterity required when the company's multi-million investment is in each mechanic's hands for two seconds. Martin, who knows the meaning of performing under pressure, was a dry-mouthed bag of nerves. And this was before he received the final nod on race weekend to play the part for real on Sunday.

Xavier Bonilla/NurPhoto via Getty Images

The intense build up of endless practice and the search for perfection begins in the factory at Grove. The days of an F1 mechanic rolling a cigarette and having a mug of tea in a spare moment have been replaced by intense work in the gym, honing the muscles and limbs required for that split second of fierce activity.

Then there's practice wheel changes. And more practice wheel changes with the slightest fumble coldly highlighted by big red digits on the stopwatch. If Martin mumbled 'Sorry' once, he said it a hundred times as he was the last of the 22 to straighten his back. And each time he quietly cursed himself, you could sense a grim determination to get this thing right. He is, after all, a racer and hence a perfect fit for the team.

Taking on Martin started as an idea worth considering -- no more than that -- but quickly developed a momentum of its own. The lean and cheerful biker was immediately at home, as witnessed by a familiarity with tools and a readiness to pick them up and get stuck in without having to be instructed.

Guy Martin's TV appearance was "no sop", writes Maurice Hamilton: "The boy was expected to perform. And he knew it." Sutton Images

On top of that, events on the track could not have been scripted better for the programme producer, even if the team did not feel that way from their point of view as Felipe Massa stuffed his car early in the very first practice session. Martin was straight into a rebuild, diving under the chassis and doing his bit in that efficient and eerily silent operation when not a word is spoken during such emergencies.

All of that -- and more -- contributed to approval for his role as left-rear tyre remover on race day. Given Williams's close fight in constructors' championship, this was no sop to the script. The boy was expected to perform. And he knew it.

Martin was told the worst-case scenario would be a 'stack' when, on very rare occasions, track conditions and tactics called for both cars to come in at the same time. On cue -- lap 29 actually -- that's exactly what happened, Martin coping with the urgent queue of two hot, blipping race cars.

Guy Martin (yellow helmet, background) waits at the left-rear tyre position ahead of a pit-stop Sutton Images

And there was more. In a very rare moment of confusion, information over a last-second change of tyre compound was not relayed properly, causing the usual high-speed ballet to briefly become a ricocheting ruck with 17kg wheels.

Fair play to Williams; they did not ask for the embarrassing screw-up to be consigned to the cutting room floor. That was totally in keeping with a film that took the audience beyond the pit stop and behind the scenery, showing how the F1 circus actually works.

It is as revealing as it is tense in places; a terrific advert for the team and the sport; well worth finding on catch-up if you haven't seen it.

'Speed with Guy Martin: F1 Challenge' Channel 4