Excellent point @M61A1. I was going to mention the shear gradient in the lubricating film that depends on the bearing surface speed but I stopped. For those interested there are some really easy-to-read articles that show the effect of (bearing or piston) surface speed on oil film shear and how the speed gradient contributes to friction, heat and wear. Just google this for one example.
Then I thought of the audience
Bottom line, the surface speed of a bunch of tiny things rotating very quickly might be less than one big thing rotating slowly and doing the same job. Or it might not. Maths, its hard to argue with but I am sure some will still try. Remember, a room full of mathematicians made nuclear bombs possible. Everyone else just tested the results.
I went googling for the number of R1150 engines made. Its less than 99,999 because that's how many digits there are in the engine number sequence. The highest number I can find is ~52,000 for a 2004 model so a good guess would be ~60,000 examples by the end of 2006 of which a very tiny number would have ever been documented for overall condition prior to being scrapped because nobody cares. I am sure for $10,000 you can still get one with 500 hours (40,000 kms) on it and a free motorcycle!
Another fun math fact, Rotax made and sold 50,000 "912" engines in 25 years to 2014. By 2020 if Rotax keep going at the same rate that number will be 62,000 new 912 engines. It reminds me of the joke conversation between God and Arthur Davidson about God's design of "Woman".