Heck, I did once 180km on a mountain/cross bike. It was around Lake Geneva, normally racers do it in sub 4ish hours time, it took me 9.5h. Wind was the biggest

Heck, I did once 180km on a mountain/cross bike. It was around Lake Geneva, normally racers do it in sub 4ish hours time, it took me 9.5h. Wind was the biggest enemy, when doing circle eventually you face it. I did little to no biking beforehand, being generally fit from hiking I managed somehow, but last 50kms was sufferfest. And last 1km very steep uphill in Lausanne I had to go down the bike 4x, but refused to take public transport. The biggest issue, aside from general tiredness at the end was neck/shoulder pain. It just isn't healthy position to be in, and that's for mountain bike, for road bike it must be much worse. Impotence / fertility issues are also frequent for devotees from what I heard, even with appropriate saddles. My boss had serious neck pain issues that doctors were baffled with and unable to cure. Told him to stop road biking, refused to do so. But eventually he stopped and problems disappeared for good. Once in a lifetime experience, glad I did it but sure as hell not going to repeat it. Plus I've found more interesting sports for me.