None of this explains to me how a relative unknown like Geschke can break away and sustain that pace for so long without being chased down by the power of the peloton or a group. I'm not insinuating drug abuse here, I'm merely wondering how, if the posts above are correct, the race allows this to happen. Maybe
@HF2300 can explain to me in a little more detail the reasons why it worked for Geschke that day.
No guile intended, I'm simply curious.
Your post requires two assumptions for your assertion to be correct (amongst other things). Firstly that every rider in the race is riding as hard as they can in each stage, and secondly that every rider in the peloton is concerned about beating Geschke.
In reality, riders try to minimise the effort they make in the stages they are not concerned about. Hence the existence of the grupetto of sprinters that try to get through every mountain stage as close to the time limit as they can. So we are not talking about a full peloton trying to chase down Geschke, even before we consider team tactics.
Further, many of the remaining riders are riding in support of their GC contender. This includes all the riders in the Sky, Astana, Movistar, Saxo-Tinkoff, Trek Factory Racing, Lotto Jumbo, IAM Cycling, AG2R and to a lesser extent Cannondale-Garmin, FDJ and Europcar (I would question whether Europcar were 100% focussed on Pierre Rolland). This is a vast proportion of the peloton. Only a few teams are not riding for an overall GC contender. These GC teams I've listed don't care (really) who wins a stage late in the race. It has no impact or bearing on their measures of success for the event overall. Geschke finished nearly two hours behind Chris Froome - no point in anyone from these teams wasting one calorie of energy chasing him down.
So in reality, there are not many participants concerned about Geschke. On that day, he had the form and played the tactics right to beat the handful of riders that were. It is for these reasons that stages can be described as 'perfect for a break away'. These are usually in the final week, when priorities have become more focussed, and also where riders are more exhausted from efforts earlier in the Tour and so for a rider who is in good shape, it presents an opportunity to race well and win.