Mollema, who currently rides for Team Belkin, has agreed to join Trek for next season in a move that Cancellara is certain will benefit the 27-year-old's time trialling.
"I already discussed it with Bauke in the Eneco Tour," Cancellara told ad.nl.
"He also told me about his failed trial in the Tour and the problems with his trial bike. I can give Bauke advice and so he will improve compared to his last time trial in the Tour. It is not so difficult.
"Bauke shakes a lot on the bike. He will have to work on that. There are so many people with Trek that can help him. Designers and plenty of other experts."
Cancellara, 33, holds the record for most victories in the UCI Road World Championships men's time trial with four.