There's been a fair bit of research done into impact of whole body vibration and hand arm vibration on rider fatigue, but it's usually directed towards automotives. It's a very complex issue, with different frequencies having different impacts, and even sinusoidal vs consistent amplitude being significant.

I did find a study out of China regarding motorcycles, which found that riders are consistently exposed to levels of vibration significantly higher than automotives, and exceeding the maximum recommended guidelines for autos.

This got me wondering if vibration is a big part of the fatigue I experience at higher speeds where the tach has to be at 6k+.

I've been eyeballing NC700s as an upgrade, and having an engine that produces peak torque at 4750 RPM is suddenly much more appealing. I wonder if that would translate to a lot less vibration and thus less fatigue.

Anyway, something I'm pondering today, so I thought I'd mention it here.