I just came past this thing after looking around the old fortress. Sadly it was out of service and most likely won't be fixed today since it's sunday and the mechanics have their day off. Would have loved to try it out.
I was talking to a local and he said most locals rather just push or ride up the hill, since using the thing is kinda hard. May make you do the splits. It's also out of function during the night due to drunks getting wrecked on it. I guess there is a reason that it is 'the first and only bicycle lift in the world' as a tourist guide pointed out at the bottom of it.
Still really cool, i will check back again later, maybe some mechanic is bored on his day off, i am taking a day off myself here in Trondheim.
It's quite tough, at least with a heavy bike, i think that makes it quite a bit tougher. I made it a few times, haha. Took me four tries to go all the way up though. I think the irregular grade makes it kinda hard, but with the right technique, totally straight leg, and weight on that leg it's good. Problem with a heavy bike is that you of course have to put quite some weight on the handlebar to push that beast up there.
edit: just tried it without bags again, it's quite a bit easier.