Keep your friends close and your enemies closer. Whilst perhaps unfair to suggest the respected Sunday Times scribe and best-selling author of Seven Deadly Sins, David Walsh is an ‘enemy’ of Team Sky, he most certainly is a journalist: which you often get the impression (especially if you’ve ever watched a Brad Wiggins press conference) is the next worst thing for the all-conquering yet undeniably polarising men in black.

Walsh’s at times fascinating, and at other times frustrating, fly-on-the-wall book documents significant portions of the 2013 WorldTour season and, in particular, Chris Froome’s triumphant spin across France in the 100th Tour de France. Taking a leaf from the military, Walsh was embedded within the team and effectively given carte blanche to come, go and ask as he pleased by Sir David Brailsford and co, the level of access he enjoyed to all corners of the uber team, including riders, sports directors, doctors and support staff, was unprecedented in the context of a 21st Century cycling team. A journalistic dream.

Whether it was intended or otherwise, however, you get the distinct feeling Walsh was so enamoured by his very special treatment that on more than one occasion he did pull his punches; backing off when he might have gone in far harder; not so much to twist the knife and make his hosts squirm, but to genuinely exhaust all avenues of enquiry. Or if he did ask the really awkward questions, the answers were off-record and never made it into print. You can totally understand why he might stay in the small chainring, of course. Biting the hand that feeds you rarely ends well. But it’s a fine (blue) line.

Of course, as the hugely experienced Walsh admits – and states at frequent intervals in the book – there was always a risk of being labelled a puppet and/or patsy for Team Sky’s PR machine when he agreed to the unique invitation. Accordingly he’s at pains to point out the words and observations are his and his alone. I tend to believe him, although Hamlet does spring to mind, “He doth protest too much, methinks.”

Why did Sky agree to do this anyway? Well, not for purely altruistic reasons, that’s for sure. As Walsh himself observes on repeated occasion, Team Sky likes to be in control. On the road and off it. Yet beset with the exhausting and inescapable cynicism of success in the Post-Lance world, they were searching for ways to ‘prove’ their methods are above board. What better step than to bring someone into the fold with decades of independent credibility and a strong position on doping to help rubber stamp things? “Look at us world! David Walsh says we’re clean so we must be – please leave us alone now.”

It makes total sense in theory. But given the mixed reaction to the book since it was released late last year, pretty clearly it will require far more for the doubters to be silenced (if that’s even possible of course).

“Team Sky fights on two fronts all the time. The battle to be cycling’s top team through constant reassessment of the targets and potential benefits of training. And to be demonstrably clean, insofar as that is even possible in a world where we say, ‘Well let’s see in ten, fifteen years’ time just how clean your were in 2013′.”

Personally, as a cycling fan with only occasional dealings with the upper echelons of pro cycling, I found the 691-page story fascinating – a hugely insightful tale of the inner workings of an elite sporting team, from the ever-shifting dynamics and politics between riders and soigneurs (or ‘carers’ as Sky calls them) to the relentless and almost fastidious drive to deliver marginal gains across every facet of the Team, under the careful stewardship of Tim Kerrison, Rob Ellingworth and Brailsford himself. I thoroughly enjoyed it as a ‘cycling read’ and, chances are, you will too. Problem is, despite Walsh being more than capable of delivering a bold and uncompromising book about the finest cycling team on the planet right now, the general tone – even at its pointiest moments – is far too conciliatory to be treated as a truly hard-nosed piece of independent investigation; hence the naysayers are largely unimpressed with his ultimate view that TeamSky is indeed ‘clean.’ Of course, they quite probably are. It’s just that in the deeply cynical world we now inhabit, the general softness of Walsh’s approach and his desire at times to straddle both sides of the fence leaves his conclusion feeling hardly compelling. He may be British, but to me he’s done a magnificent job of impersonating Switzerland.

As a fascinating and easy-to-read book about the inner workings of a top cycling team, I’d give it 9/10. As a piece of no-holds-barred investigative journalism, it’s hard to give it any more than 6.