A focused Chris Froome on the Sky bus with Ian Stannard (Image credit: Scott Mitchell)

Nowadays they'd call it embedding but back then it was just a bit of a novelty. One evening in September 1982, David Walsh trotted out onto a field in Ballycommon with the Offaly Gaelic football team. Then a 27-year-old journalist with the Irish Press – "oh, I was fit as a flea then" – Walsh wangled an invitation to participate in one of the final training sessions of a team on the cusp of its finest hour.

Two weeks later, in front of 62,000 people on a sodden afternoon in Croke Park, Dublin, Offaly would pull off the greatest of upsets, defeating a Kerry team chasing an unprecedented fifth successive All-Ireland championship. High up in the Hogan Stand, Walsh sat mesmerized. "I don't think the piece I wrote about it was much good, but when Offaly went out and beat Kerry in that final, it was one of the most joyous sporting occasions that I've ever witnessed because I was watching guys I'd trained with ten days earlier produce the greatest performance of their lives and beat the greatest team that Gaelic football has ever known," Walsh says.

Those were different times. Walsh’s most recent brush with embedding was a rather more divisive experience. "Yes, I've taken vastly more flak for this," he admits of his season behind the scenes at Sky, which he described in a series of articles for The Sunday Times and in his recently published book, Inside Team Sky.

Walsh's conclusion is that Sky does not have a doping culture and, in particular, that its leader, Chris Froome, is a credible Tour de France winner. "I'd rather say I believe Chris Froome is clean than say I believe Team Sky is clean, because that would preclude the possibility that one of their riders might be investigated for doping, which of course we know has happened to a degree with Jonathan Tiernan-Locke," he says.

Just a year on from the publication of Seven Deadly Sins, his account of his pursuit of the Lance Armstrong story, such explicit faith in Froome and Sky has puzzled a vocal section of his previous constituency, perhaps not so much for the opinion itself as for the emphatic manner in which he has expressed it. But the book has not been without its supporters either. Nobody, it seems, has been indifferent to Walsh's stance and, by extension, to Team Sky's recent run of success.

A week after the publication of Inside Team Sky, Cyclingnews questioned Walsh on how he arrived at such a definite conclusion, and discussed the immediacy of critical reaction in the age of the e-book and Twitter. "People say I've gone out on a limb. I don't feel in any way that I've gone out on a limb," he says.

Cyclingnews: How have you found the reception to the book? Was it what you expected?

David Walsh: It's been interesting. I've had lots of feedback because that's what Twitter does, it creates an avenue of direct contact between you and people who have read the book and haven't read the book but have opinions on it. If I were categorising it – and this may sound self-serving but it's actually true – the people who've read the book have been very complimentary and the people who haven't read the book have been much less complimentary. People have read a free chapter on Amazon and made big decisions based on that.

I've written books that I haven't much liked but I think this is a reasonable book and I'm pretty certain that if anyone comes to it with an open mind, then it will contribute a little bit to their understanding of what Team Sky is about.

CN: Dave Brailsford invited you to spend the season with Sky after you interviewed him last winter. Did you have the freedom to spend as much time as you wanted there? Because it wasn't clear from the book if you were simply coming at specific times dictated by the team…

DW: No, I could come and go as I pleased and every decision was made by me. Obviously, before going to Mallorca, I spoke to Fran Millar and said I wanted to be sure Wiggins and Froome were both there at the same time. I didn't want to go there and not be able to see them train.

CN: I’m playing devil's advocate here, but you said the team knew in advance when you were coming and sent a driver to pick you up – was there not a chance that they were dropping off a Doctor Ferrari-style figure at departures before they came and picked you up from arrivals? Did a thought like that ever cross your mind?

DW: No, I have to say that didn't cross my mind because I just didn't think they were the kind of team that would have a doctor that nobody knew about working with them. That would take a bit of doing because somebody somewhere would recognise him and say, “"what’s that guy doing in that hotel?"

If they were intent upon fooling me and used it all as a ruse to convince people, that would make the team out to be incredibly cynical. If you'd said to me before I joined the team, I'd have admitted that it was a possibility. But having spent the guts of ten weeks with these people, I can tell you now that it's not a possibility because the people who are the pillars of the management, people like Brailsford, Tim Kerrison, Rod Ellingworth, the lead doctor Alan Farrell and the lead carer Mario Pafundi, they're just not those kind of people. They're not the kind of people who would be duplicitous in that way.

That’s just my opinion having spent a lot of time living in their world. Remember that every single day, I was always travelling with Sky people, generally with senior management, and I would sit at dinner and breakfast every day, often with the rank and file, the carers, mechanics, the rest of the management team. And there isn't one guy who worked in that team, especially on the Tour, that I didn't have a pretty lengthy conversation with. And with many of them, the conversations were multiple.

Between the Giro and Tour, I spent maybe 40 hours in a car with Rod Ellingworth. That's a lot of conversation, a lot of going over background, a lot of finding out about a man. If somebody told me now that Rod Ellingworth was actually secretly bringing drugs into the team, I'd say that’s an absolute lie. Why? Because I know the man.

CN: You spent 40 hours with Rod Ellingworth as opposed to 10 minutes with him after a stage, but I think most people who have had any dealings with the team would have known beforehand that Rod Ellingworth is a thoroughly decent guy, that Chris Froome is very polite, that Dave Brailsford is an intelligent guy but one who can be very prickly in his dealings with the press… In your book, you've fleshed out the perceptions we have of these people and their personalities, but is that in itself enough to make the sweeping declaration that this team is clean?

DW: The common thing about those who are sceptical and don't believe is that they compare Team Sky with US Postal because of their success, right? But before Armstrong ever joined US Postal they had Prentice Steffen. I interviewed Prentice Steffen in 2001 and he told me about Mark Gorski and the letter and threats he got from Mark Gorski and how he was sacked. And that made me sure that in 1996 or 97 – two or three years before Armstrong ever joined the team – this team had decided to dope.

What's to stop me finding that out about Team Sky if something like that had happened? I didn't have as much access to US Postal as I had to Team Sky. I did talk to some of the people who left the team. I've listened to Steven de Jongh and Bobby Julich, two guys with good reason to be resentful about what happened to them at the team. Do any of these guys say one thing that links the team to doping? The answer is no, they don't. Did people who were let go from US Postal talk? Yes, they did. It's natural – disgruntled employees will talk. That’s guaranteed. But in the case of Sky, these guys have never said one thing that connected the team to doping. I do think it's possible to find out [if a team is clean] and that's what journalism should be about.

CN: When you arrived in Corsica at the start of the Tour, you wrote that you were "excited but holding on to your scepticism." The scepticism seemed to disappear pretty quickly. Was there a precise point or was it a gradual process?

DW: No, it was a gradual process of tiny little things that happened. We knew at US Postal that Armstrong always wanted a room alone, perhaps for good reason. Chris Froome preferred to share it with his mate Richie Porte. Then you think, the two of them could be doping and doing it together. But from what I can see, after the second stage of the Pyrenees people changed their mind from "Team Sky are all doping" to "No, it's only Froome who's doping" because they felt, "the other guys are normal, you saw what happened today." Because Richie Porte had a few bad days, people started saying that made him believable, and said it must just be Froome. Now imagine Chris Froome in a room with Richie Porte – can you imagine Froome was doping and Porte wasn't?

CN: I really don’t think it’s that simple. If anything, the fact that so many Sky riders had a bad day at once was probably viewed with even more suspicion…

DW: There was a lot of that on the Tour. I mean, there was the situation where Nicolas Geay on French television asked Brailsford if all of the riders apart from Froome deliberately performed badly to show that they were clean. That's how ridiculous the level of debate became. That's the depths to which it descended during the Tour. And I thought that’s where we're at now, with this kind of nonsense being peddled as journalism.

CN: You highlight Tim Kerrison's role and suggest his coaching techniques have been a huge factor in Sky's success. But did you speak to coaches on other teams to compare what they do? The implication in the book is that Sky are successful because they work harder than everyone else, or because they work smarter than everyone else. Now maybe that’s the case, but it's a problematic argument because that exactly the kind of rhetoric that was being put forward as an explanation for US Postal's performances…

DW: I think your question is an absolutely valid one and the answer is no, I'm not intimately acquainted with how other coaches in other teams operate. But I did listen to the Sky riders who came from other teams, and to a man, they all said the training at Team Sky was on another level to other teams. I spoke to Bobby Julich and I know he thinks Sky are on a completely different level to BMC, who he has worked with. I do know that Steven de Jongh spoke on Dutch television and said Sky are on a different level to Saxo. So these guys who have worked on other top teams all agree Sky were on a different level.

The point wasn't so much that Sky are doing this so much better than everyone else, the point is that they're doing it intelligently and they're doing it in a way that the riders believe is very good for them. "Stick with this programme and you will get better" – that's the feeling I got from the riders. I've seen lots of other sports. I've been in different rugby and football environments, I've seen the English swimming set-up, and Sky have created a really impressive environment for people to prepare.

I remember at this year's Tour, David Lopez turned up at the Tour. At the table, he was eating Nutella. Because he was relatively new to the team, he had no idea of how that would offend his teammates. But it did offend them. They just didn't like it, as in, "That stuff is no good for you. We're here to eat the right food, and you bringing that to the table is lowering the dietary and nutritional standard." I just thought that kind of attitude was impressive. That's what Sky have created, and I found it impressive. Maybe the other teams are doing it better, but from the bits and pieces I heard, it doesn't seem that all of them are.

CN: Well, quite a lot of teams over the years have enacted some kind of Nutella ban during races. It’s the same with the pre-breakfast training rides. I think Davide Rebellin used to deliberately train on depleted reserves to accustom himself to the demands of a 250km classic, and he went on to test positive at the Beijing Olympics… The point I'm getting at is that these things by themselves don't necessarily prove anything one way or another.

DW: Of course it doesn't mean they're clean, but tell me something that indicates they're dirty. You've mentioned US Postal as a point of comparison, but two years before Armstrong joined the team, there was already evidence that the team was heading down a doping road. But why can't anyone come up with something like that about Sky? If that rates a 6.5 on the Richter Scale of suspicions of doping, why can't anyone come up with even a 5.5 or something that makes you think 'Wow, did he really say that?' I mean, did Geert Leinders leave the team and say that he did things at Sky that weren't ethical? Has he said that?

CN: You mentioned Leinders, and as you said in your book, it’s the issue that haunts Sky like Banquo's ghost. What strikes me about the whole matter is that Sky had doctors with no cycling links until soigneur Txema Gonzalez died after contracting a bacterial infection at the 2010 Vuelta a España, and it seemed like his death was later used as a pretext for bringing in Leinders. But as soon as the Rabobank stuff breaks, Leinders is out the door and Sky are back to non-cycling doctors again. Does this mean the team's health is at risk again? It seems a very serious issue to be flip-flopping back and forth on.

DW: What evidence do you have that they used Gonzalez's death as a pretext?

CN: I don't have evidence but it certainly seems to be casting a terrible aspersion on the doctors who worked on the team at the Vuelta in 2010. It's basically saying that they weren't up to their job and a man died as a consequence.

DW: So you don't believe it was a pretext, you just don't know?

CN: I don't know.

DW: Well Barry, your question reflects your bias and it's like all the people out there on Twitter who are telling me Sky are this and Sky are that. Show me the evidence. Give me a lead and I'll go and investigate it. I'd be the happiest man in the world to write the story because I like writing good stories.

I spoke at length with people about Txema Gonzalez's death and the carnage in the team at the time. There was a feeling from the riders that the doctor at that time just wasn't cycling empathetic. He didn't understand what people on the road needed. It was a separate but related issue to the tragedy of Gonzalez. I think Dave Brailsford has admitted that he made a really bad judgment call in going for doctors with cycling experience at that time and Geert Leinders in particular, and it was a wrong decision and it backfired on him big time when the truth came out about Leinders and they asked him to leave.

It was definitely a mistake, it was definitely wrong. The very least Brailsford needed to do was to say, "we have changed our policy here, guys, because we feel we need people with expertise of the cycling game." That should have been explained at the time. And you could argue that they made a big mistake in going for a doctor from a team that was clearly associated with doping.

But the underlying question is this – did that mistake mean that Sky wanted to go down a doping route? I don't believe it did, and if anybody says it did, then I'd say, "show me the evidence."

CN: People will point to the fact that Sky and the Sunday Times have the same ownership as an influence on your opinion of the team. I don't go along with that, but having played such a persistent role in chipping away at Armstrong over the years, is it perhaps the case that subconsciously you want to believe that cycling has changed partly as a result of your previous work?

DW: I think that's a fair question. I do want to believe. When everyone said that I was ridiculously cynical in my attitude to Armstrong, I thought that was unfair. I've always been a romantic of sport and I do engage with people who produce epic performances or just those who give their best. It appeals to me.

So I went back and I wanted to like the Tour again. But at the same time, I was sitting in the hotel watching people come and go, keeping an eye out for Son of Motoman or whoever. So even though I wanted to believe, I don't think my eyes were closed. I just felt Froome in particular is a really interesting man. I think in terms of his character, he's a pretty special fellow. I saw the way he operated at the Tour this year. Considering the pressure he was under, I thought his performance was very impressive. And I do have a lot of trust that he's telling the truth.

CN: You're ghostwriting Froome's autobiography next year. At what point did he approach you?

DW: It was well after the Tour. He rang up and asked if I'd do it, and I said I'd consider it. I said to him during the conversation we had, "As things stand, I do believe in you, but if you have any doubts about any part of your past, it would be great if you could go and ask somebody else." And he said, "There were no worries. There are absolutely zero worries on that basis. I wouldn't be asking you if there were, believe me."

And I do believe in him. We had a meeting during the Tour and I'm not going to talk about it, although I allude to the meeting in the book. It was a very, very private conversation and we spoke, and I do believe in the guy. That was a very private thing and it related to doping and I do believe he's clean. I wouldn't be writing his book if I didn't believe that.

CN: Both you and Dave Brailsford have been critical of the current trend for calculating and comparing power output on climbs, and particularly, the definitive conclusions that are being drawn from the data. Yet in your book, you cite a tailwind on the Ventoux as a partial explanation for Froome's performance on the climb. Is that not simply a case of fighting pseudo-science with pseudo-science?

DW: What I'm saying is that when people make calculations comparing Froome's ride with Armstrong's, for example, and they don't factor in something like the wind on the day, then it's just laughable. It's just like, "forget it, why am I reading this?" All the variables get excluded and the concentration is on one bit of evidence, which is the time to get from A to B. Now the time is affected by a string of things, yet all of these get eliminated and I ask myself, 'what are we doing here?'

CN: So just to clarify – your reference to the tailwind on the Ventoux is to illustrate the flaws of power calculations rather than to provide an explanation of your own for his time?

DW: Yeah, I don't want to be providing an explanation because I don't know. I absolutely don't know.

CN: Later that week, L’Équipe published the so-called Froome Dossier, where his power figures were analysed by Fred Grappe of FDJ. There was criticism that the actual numbers for Froome's power data were not published in the newspaper, but I felt the bigger gap in the information was the lack of data from before the 2011 Vuelta. We already knew that the 2011 Froome and the 2013 Froome were at a similar level of performance, it's the nature of the leap in quality from before the 2011 Vuelta that's of real interest. Is there more information that Froome or Sky could provide to fill that gap?

DW: I think they could. I've seen data from Chris Froome's Barloworld years, from 2008 and 2009. And that stuff is very interesting and it would certainly indicate that what Froome has been doing at Sky is not actually that much different relative to his loss of weight from Barloworld to now. I've seen what the exercise physiologist at Barloworld has done and his view is that there is certainly nothing that Froome is doing now that is that different. I've seen that.

CN: Sky's zero tolerance policy saw Steven de Jongh and Bobby Julich leave the team last year, but there are some guys who raced successfully during the Lance Armstrong years who are still on the staff at Sky now. One example – and there are a few – is Dario Cioni. He's still working for Sky, so he's clearly signed a form saying that he never doped. He finished 4th overall in the 2004 Giro d'Italia. If Cioni was clean – and we assume he's signed a declaration saying that – then that is an amazing story. I would imagine he would be a very interesting guy to talk to, if he rode clean at the business end of a grand tour during that era… He's only mentioned in passing in your book. Did you speak to him?

DW: I did speak to Dario, I interviewed him for about two hours. You say he'd be an interesting guy to talk to. Well, you can ask him some interesting questions, but I wouldn't agree that he's that an interesting guy to talk to or write about. His view is that he didn't dope. I think if you go back on Dario's career, he had some point where he exceeded 50% haematocrit [ahead of the 2004 world championships – ed.] and the UCI decided that he was naturally pre-disposed to a high haematoctrit, as Jonathan Vaughters was and plenty of other riders were.

But you know this whole thing about Sky's zero tolerance – and maybe I should have made a big thing of it, but I didn't in the book, and maybe that's a weakness – but I don't believe in it. I don't think Sky are right to have it. I think it's not good enough to say to somebody 'did you dope?' and that person says 'no, I didn't dope' and you accept their word and that's it. You feel you don't need to go any further than that.

There was a time when I thought I should be investigating every guy on the team, every mechanic, everyone. Go back into his past and find out did he aid or abet anybody to dope, and prove that Sky have hired somebody with doping in his background. And you know what? I said I wasn't going to do that because I actually don’t believe it’s fair on the guy.

Maybe I can be accused of not going and outing some guys from Sky who have doping in their past and signed a form they shouldn't really have signed, but I just didn't have the stomach for that. I didn't want to ruin someone's life on something that I saw as unfair. I don't believe Sky should have a zero tolerance policy like that.

If Sky decided to employ Jim Ochowicz in some management role, and he signed a form to say he wasn't involved in doping, well I would investigate Jim Ochowicz because a) he would be a very high ranking member of the team management and b) there are real suspicions that he was involved in a very serious doping conspiracy. But if it's some guy who's maybe the fourth or fifth highest-ranked carer, and fifteen or twenty years ago, he was a rider who might have doped… Do you want to spend all of your time investigating him to maybe show that he might have been involved in doping and get him kicked out of the team? Well, I didn't do it, and I don't see anyone else doing it either.

I think the zero tolerance policy has come more from BSkyB, the people who are putting up the money, rather than the people in the team. I think Dave Brailsford is trying to make the best of it, get the guys to sign the form so that legally they're covered but is the team forensically researching the background of all the guys it employs? Clearly not.

CN: You describe him Dave Brailsford as "incredibly open." He certainly didn’t seem that way when he rang Cyclingnews to complain after we asked him about the Leinders investigation at the 2012 Worlds. Do you think it's fair to say that your experience of Sky and Brailsford in particular is very different from that of just about every other journalist in cycling?

DW: I wouldn't say it's very different to every other journalist in cycling, although it's certainly different to your one. What does Owen Slott say? What does Richard Moore say? What does William Fotheringham say? My guess would be that they find Brailsford pretty good to deal with. I think I've spoken to Owen Slott about it, and he's generally been ok with him. I did find him incredibly open and I think anybody who reads the book will find he's incredibly open. He's told me far more than most team managers in his situation would have done in my view. That's only my view. Someone else will say he's not. I found him incredibly open.

CN: There was a passage in the book that I found problematic. It's an interesting analogy but one I found to be a bit over the top. You compare Contador and Riis to Barabbas and, by implication, Brailsford and Froome to Jesus, saying the crowds are asking for them to be nailed to the cross… Have you any concerns that statements like that could come back to haunt you in ten or twenty years' time?

DW: I don't believe they will and I don't worry about stuff like that. If you consider all the talk there has been about Leinders – and it's valid, because Sky set themselves up as a team who wouldn't employ a doctor from a cycling background – and we have doctors in other teams who we know have been involved in doping and are still involved in those teams, and nobody raises an eyebrow. It's not a story and I just think different horses for different courses here. What's sauce for the goose is not sauce for the gander. I do think Sky have been subjected to standards that no other team have been subjected to. You can say they set themselves up as being whiter than white and deserve that kind of scrutiny, but I still think it would be interesting if other teams got something close to that level of scrutiny.

CN: In your Sean Kelly biography in the 1980s, you wrote a chapter on his stimul positive at the 1984 Paris-Brussels but didn't draw an explicit conclusion on the affair. Between that and ghosting Stephen Roche's autobiography, you've had experience of being let down by guys you had grown close to. Are you concerned that in years down the line there might be a similar betrayal of trust from Sky?

DW: No, I'm not because I was wrong about Kelly and I was wrong about Roche. What I did in both of those cases was really poor journalism and I knew it at the time…

CN: Yes, in Seven Deadly Sins, you recalled hearing rattling pills in Kelly's pocket on the start line of Paris-Brussels, an incident that you didn't mention at the time… I take it there are no similar sins of omission, as it were, in the Sky book?

DW: No, and I think I've explained this in Seven Deadly Sins. At that time in the early 1980s when I started covering cycling, I was a fan with a typewriter, and Kelly was a hero. When I heard the rattle of those pills, I knew what they meant but I didn't write about it in my biography of Sean Kelly. Were there things that I saw with Stephen Roche that I should have questioned him about? Yes, there were things. Did I question him? No.

The journalist I am now wouldn't have admired the journalist I was then. I'm not trying to cover that up. I was a fan with a typewriter, and thankfully somewhere along the way, I became slightly more hard with my questioning and slightly less of a fan. I didn't go to follow Team Sky as a fan, I went to follow them as a journalist. And I guarantee you that there is no equivalent of rattling pills or other stuff I saw and ignored in that era at Team Sky. Absolutely no equivalent.

CN: On the final Sunday of the Tour you wrote: "The mob was baying for Froome's blood on the Alpe. They were wrong when Armstrong was winning. And they are wrong now about Froome." The expression crops up again in the book, and it's an emotive wording that didn't sit particularly well with me. I’m curious about it. Who is the mob? Is it the press? Is it everyone who isn't sitting on the Sky bus?

DW: Go back and take the context of the article. I was describing what the scene on Alpe d'Huez and to me, they were a mob. At one point, Rod Ellingworth stopped his car. This guy was shouting "Doper, doper." And Rod stopped his car and said "who are you?" The guy said he was Danish. And Rod asked "Do you think we’re doping?" And the guy said he wasn't sure. Now, as part of the mob he was sure. Singled out and asked as an individual, what do you believe and what's your basis for believing it, he didn't have a strong view. He was very happy to be part of the mob. And I wasn't referring to journalists in any way when I said that.

Because when Lance Armstrong was going up Alpe d'Huez, mostly the mob was cheering him. They loved him. And now as Chris Froome was going across the line at Mont Ventoux, the mob was jeering him. There was booing when he crossed the finish line – not everybody, a minority, but you could still hear it. It wasn't difficult to hear.

CN: Well, I think there was some booing of Armstrong too, particularly in the later years. He certainly complained about the reception he got on Alpe d'Huez during the time trial in 2004…

DW: Well, if any journalist felt I was referring to him or her, they're completely misreading it. That was never the intention. The context was the mob on Alpe d'Huez. A lot of them were incredibly hostile to Chris Froome. He had guys with syringes splashing stuff into his mouth. Richie Porte and Pete Kennaugh told me they had people spitting on them on Alpe d'Huez, almost constantly. Is that the kind of behaviour we want to encourage?

CN: I suppose the main issue with your book is that you take such a strong and explicit stance in stating that Sky are clean. I'm not sure if the evidence is there to make that call either way. We don't know. Was it tempting at any point to write a colour account of a year with Team Sky and let people draw their own conclusions, perhaps a bit like Daniel Coyle's book, Lance Armstrong’s War? Or did you feel that would be a cop-out?

DW: Exactly and you know it was a cop-out. Dan Coyle knew they were doping. He knew it, but he didn't write it. It was a brilliant book, flawed by that. And I've said that to Dan. The easiest thing in the world to do is to sit on the fence, Tweedledum and Tweedledee, and let you the reader make up your mind. I don't believe in that.