I like Tom Dum's chances, just watched some Team Giant build up videos, & he has had some extra training on the course & Giant seem to be paying an awful lot of attention to the details of TT. Negative will be he starts ahead of Martin. Malori, probably really is 3rd at best, where you can get 16/1 ew 1/4 odds. I've also in the past underestimated Sparticus in the past, when he really wants it!
I've thought about it a lot, and backing Dumoulin at 3/1 really does make sense, as the ITT is basically a two horse race. The question is for how much? I would not recommend risking more than £20 of Tikay's hard-earned. Also, Cancellara will beat Malori into third IMO. Two races this year against Malori and won both. Plus he is super motivated in what could be his last TdF, and could make a bid to wear yellow after stage 4 if he has a good ITT.