So I decided to make this post entry, just to give you something to look at. On the right the TR1 crank and on the left the XV1100 crank. You don't have to be a physics-genius to see, that the 1100 crank is quite a bit heavier. (Exact numbers to follow and will be inserted here.)
Otherwise the cranks are pretty identical except for one, minute detail:
The XV1100 crank has got a slightly larger thread on the alternator shaft.
Which is why, you can't swap the nuts around.
As a final note: XV1100 cranks are actually 1.6kg heavier than TR1 canks, which only weigh 9.6kg. The more moder XVS1100/BT1100 crank comes in at 8.4kg.