As I mentioned, I just got a Rans CF bike and am enjoying it quite a
bit. A friend of mine got his last spring. So far he has about 2,500
miles on it (4.000 kms).

He mentioned that the Rans doesn't wear chains or sprockets like
conventional bikes. He said he has no appreciable chain wear over that
period where he'd have at least detectable wear and maybe a new chain
needed if it were a conventional bike. He said the reason was the longer
chain meant less stress per link thus less wear thus the entire drive
train lasts longer.

I can't see it. Take a chain of 10 links. Suspend it from an overhead
and hang a 30 kg mass from it. The stress per link is 30 kgs plus a bit
for the mass of the chain links downstream. Now take the same setup, but
make the chain 40 links. IMO, the stress per link is the same.

I can't deny his chain is almost new after 2,500 miles but I am having a
tough time believing it's due to the longer throw between chain ring and
cassette on the Rans compared to conventional bikes.

Am I missing something?