10. Titanium fracture-split connecting rods


Josh Hayes’ four-time AMA Championship-winning R1 must make do with the steel connecting rods it was born with per the AMA rulebook. Plenty of engines use fracture-split connecting rods, but the new R1 is the first production bike to fracture titanium ones. (Fracture-split means actually breaking the big ends of the rods, and if you thought it was just a guy with a hammer you would be wrong.)

The big titanium advantage compared to the previous R1’s steel rods is, of course, that the ti rods are around 40% lighter. Since rods and pistons are reciprocating components, i.e., ones that start and stop 25,000 times per minute, it’s easy to see how lightness here makes a big difference. When the current R1 got its “crossplane crank” in 2009, it gained quite a few pounds. The titanium rods in the new engine allowed the crank to lose them again. At 50.9mm, the stroke of the new engine is 1.3mm shorter, which also helps Yamaha claim an “inertial moment” 20% less for the new crank. Overall, it says the new engine is nine pounds lighter than before. The numbers on the tachometer don’t turn red until 14,000 rpm. Not long ago, 14,000 rpm was a big deal on Yamaha’s FZR400.