Ten years ago, it would have been hard to envisage the Tour de France starting here, or anywhere else in Germany. The 2007 Tour is remembered by British fans for the hugely successful Grand Départ in London but for German cycling it was a different kind of landmark: when the country’s broadcasters turned their backs on the Tour after a year-long rash of doping scandals and confessions involving the country’s flagship team T-Mobile.

The telecom company pulled out that November. It was followed by the backers of the country’s other two top-level professional teams after more doping cases and in 2009 the successful Deutschland Tour also ceased to exist. That seemed to mark the end of the German love affair with cycling, which had blossomed in the mid-1990s with the rise of Jan Ullrich and T-Mobile, whose distinctive pink kit remains one of the sport’s most recognisable outfits.

The suddenness with which German professional cycling expanded and the speed with which it unravelled make this one of the sport’s cautionary tales, as the Tour’s organisers acknowledge; the race director, Christian Prudhomme, calls its history “a barometer of the troubles of our sport”. The hope is the Tour’s arrival on the banks of the Rhine will prove to be another landmark as the sport rebuilds in Germany on the back of champions such as Marcel Kittel and John Degenkolb and a new and slightly kooky team for the fans to love, Bora-Hansgrohe.

So far, so simple. This being the Tour there is also a hard-nosed commercial element to this Grand Départ; it will support the rapid expansion of the Tour’s parent company Amaury Sport Organisation, which will relaunch the Deutschland Tour next year, just as the start in Yorkshire in 2014 permitted the company to gain a foothold in Britain. The Tour travels well but it does not leave France without an eye to the bottom line.

Moving on from the sport’s past is never as seamless as the marketing men would like, hence the vexed question of Ullrich, disgraced in Operation Puerto in 2006. The last German Tour winner was left off the guest list for the start, prompting the unlikely sight of Kittel and Lance Armstrong – admittedly with different agendas – appearing to agree that if the Tour can find space for Richard Virenque, it could probably have asked the genial Ullrich to pop along and press the flesh.

British cycling’s recent travails have been in a different register to the scandals that all but wiped out professional cycling in Germany. For all they have revealed about Team Sky’s management and methods, the package saga and the question of Sir Bradley Wiggins’s therapeutic use exemptions are light years away from the train of events that brought down T-Mobile on sport’s register of scandal. There is one key similarity, however: the sense the ethics and values of a national institution are being called into question.

Team Sky’s new white jerseys notwithstanding, that is the background against which Chris Froome – who on Friday confirmed he had signed a two-year contract extension with Sky – and his team-mates set off to defend his Tour de France title on the usual demanding route and against competition which, even in straightforward times, may prove the most severe test he and they have faced. Lacking the Dutchman Wout Poels and the Briton Ian Stannard, and with the form of Geraint Thomas in doubt, Froome’s team do not have the intimidating look of other years.

Riders of the BMC Racing team during a training session in Düsseldorf. Photograph: Jeff Pachoud/AFP/Getty Images

That was Richie Porte’s view on Thursday. In reality, Sky’s strength will only become clear at the end of next week when the race heads into the Jura mountains. As well as revealing Froome’s form – in some question after his relatively slow buildup to the race – that is where a pattern will develop. Before that, the key issue, as for all the contenders, is avoiding the crashes and punctures that can wreck a favourite’s race before it has begun, as Alberto Contador and Porte found out in Brittany last year.

Sky’s tactics are well known by now: place the maximum number of team-mates around the leader in the mountains and control the race by intimidation. For Froome’s attempt at a fourth Tour to take shape, he needs the bulk of his team-mates to come through unscathed, and his main mountain assistants, Sergio Henao and Mikel Landa, in particular. Failing which, there will be no lack of rivals willing to put the boot in.

This race has “une pleiade de favoris”, – a veritable Pleiades of favourites – in the poetic view of last year’s runner-up Romain Bardet. Whether or not the young Frenchman knows his classics – as opposed to the Classics – corresponding the seven sisters of Greek mythology, the stars have aligned to produce seven contenders: Froome, Bardet, Nairo Quintana, Contador, Porte, Fabio Aru and Thibaut Pinot. Or if he was referring to the nine stars of the constellation, add in Simon Yates and Esteban Chaves as outsiders.

Froome and Porte are both strong enough to look at the final time trial in Marseille with a similar degree of optimism but the other seven will need a fragmented, unpredictable race that will offer openings long before that.

The hope is that an experimental route, with barely any time trials and only two pure mountain-top finishes, will result in less controlled racing, but the opposite could be true, with the favourites biding their time for the obvious key moments: the road to Chambéry, Peyragudes, Galibier and the Izoard.

The last two grand tours – the Vuelta 2016 and this year’s Giro d’Italia – both threw up utterly unexpected scenarios of the kind that have rarely been seen in recent Tours de France. By the law of averages, at some point a cliffhanging Tour to match 1989 or 1987 – the last time it started in Germany, if that is any omen – will happen again and there is better reason than usual to hope it could be this year.

“It’ll be one of the tightest Tours we’ve seen for a long time,” predicted the Orica sporting director, Matt White. As ever, the road will decide.