billyk
Guru
I had occasion to ride an upright bike the past few days, including on the commute route I’ve done hundreds of times on my Quest2. Same wheelbase, similar lowish-pressure tires (75lbs). The Q is suspended (upgraded air shock plus the dinky front shock), the upright not.
It’s a bumpy ride: bad tree-root bumps on the bike trail, typical lousy Seattle streets. But the upright was more comfortable on the bad spots - bumps I’m deeply familiar with seeming just much easier to take on the upright than on my Q. I was not deliberately standing up on the pedals to take the shock in my knees.
Why? I can think of three hypotheses:
1) Bumps are transmitted mostly through the seat. Since an upright bike seat is well above the road, much of its motion is a forward and back rocking as the wheels go over a bump in turn.
By contrast, on a recumbent with its lower seat, the motion of the seat is more up-and-down, thus more uncomfortable.
2) Even if the upright rider does not actually stand up to absorb shock in the knees, a substantial part of his weight is on the pedals, so the knees bend with jarring motion and take up bumps. Similarly for weight on the handlebars: shocks are partly compensated in the elbows and shoulders.
3) A recumbent seat cups the rider’s whole butt and back, so shocks are transmitted to the head and neck very directly. On an upright, even coasting and not pedaling (thus little or no weight through the legs), bumps can be absorbed in the rider’s spine by bending and compressing, reducing shock to the head.
Probably all three come into play, but I’m inclined to the third, because today I was back on the Q and tried going over bumps while leaning forward, with my back free of the seat. Much better! Of course that is not a viable way to ride for very long.
Opinions? Even better, solutions?
Billy K
It’s a bumpy ride: bad tree-root bumps on the bike trail, typical lousy Seattle streets. But the upright was more comfortable on the bad spots - bumps I’m deeply familiar with seeming just much easier to take on the upright than on my Q. I was not deliberately standing up on the pedals to take the shock in my knees.
Why? I can think of three hypotheses:
1) Bumps are transmitted mostly through the seat. Since an upright bike seat is well above the road, much of its motion is a forward and back rocking as the wheels go over a bump in turn.
By contrast, on a recumbent with its lower seat, the motion of the seat is more up-and-down, thus more uncomfortable.
2) Even if the upright rider does not actually stand up to absorb shock in the knees, a substantial part of his weight is on the pedals, so the knees bend with jarring motion and take up bumps. Similarly for weight on the handlebars: shocks are partly compensated in the elbows and shoulders.
3) A recumbent seat cups the rider’s whole butt and back, so shocks are transmitted to the head and neck very directly. On an upright, even coasting and not pedaling (thus little or no weight through the legs), bumps can be absorbed in the rider’s spine by bending and compressing, reducing shock to the head.
Probably all three come into play, but I’m inclined to the third, because today I was back on the Q and tried going over bumps while leaning forward, with my back free of the seat. Much better! Of course that is not a viable way to ride for very long.
Opinions? Even better, solutions?
Billy K
