I’m thinking about this. My back is stiff right now which is not something I’ve experienced in some years. My Fuel EX has a stupid steep 78° seat tube angle. I think the more upright position is harder on the lower back than my Chameleon which is closer to 73° static. So much garbage analysis or lack thereof from manufacturers on this topic. All I read is:"this is better". Why is steeper better? "Yes" no reasons provided. My analysis is that steep seat tube angles puts a riders centre of mass which is near the belly button in front of the rear contact patch so one doesn’t loop out on steeper climbs. The real answer is longer rear centre for bigger sizes. But different length rear centre costs more to build and design so a manufacturer may lose sales from a higher cost. And every one else is doing it. And magazine writers will often call it progressive geometry. Who says? Just because it’s different doesn’t mean it’s better.
Road and gravel bikes need a different fit. You want to have a balanced position where while on the drops or hoods, you’re not leaning on the bars hard. You should be able to take your hands off the bars and hold that position without pedalling harder or engaging core muscles to hold yourself there. A mountain bike fit will be more upright so a further forward saddle position is desired. But too steep a seat angle and you’re balanced when sitting bolt upright. That may be comfortable but it’s not efficient. There is a pseudo myth about needing to put weight on the front wheel to keep from looping out on steep climbs. I say pseudo myth because it’s partly true but what a rider is doing is putting the centre of mass ahead of the rear axle. No one pushes down on the bars during a steep climb. Pretty much everyone will pull back on the bars and lean over. The lean puts the weight a bit forward and allows better pulling back to offset the hard pedalling. Watch World Cup xc. Hard climbs see the riders forearms are parallel to the ground from pulling back. No one climbs a hard trail sitting bolt upright. No one.
Oh. The 9point8 I had on my Bronson a while back had a rebadged Wolftooth remote. Maybe 9point8 are simply making their own copy now?
Aug. 10, 2023, 9:23 a.m. - Andy Eunson
I’m thinking about this. My back is stiff right now which is not something I’ve experienced in some years. My Fuel EX has a stupid steep 78° seat tube angle. I think the more upright position is harder on the lower back than my Chameleon which is closer to 73° static. So much garbage analysis or lack thereof from manufacturers on this topic. All I read is:"this is better". Why is steeper better? "Yes" no reasons provided. My analysis is that steep seat tube angles puts a riders centre of mass which is near the belly button in front of the rear contact patch so one doesn’t loop out on steeper climbs. The real answer is longer rear centre for bigger sizes. But different length rear centre costs more to build and design so a manufacturer may lose sales from a higher cost. And every one else is doing it. And magazine writers will often call it progressive geometry. Who says? Just because it’s different doesn’t mean it’s better. Road and gravel bikes need a different fit. You want to have a balanced position where while on the drops or hoods, you’re not leaning on the bars hard. You should be able to take your hands off the bars and hold that position without pedalling harder or engaging core muscles to hold yourself there. A mountain bike fit will be more upright so a further forward saddle position is desired. But too steep a seat angle and you’re balanced when sitting bolt upright. That may be comfortable but it’s not efficient. There is a pseudo myth about needing to put weight on the front wheel to keep from looping out on steep climbs. I say pseudo myth because it’s partly true but what a rider is doing is putting the centre of mass ahead of the rear axle. No one pushes down on the bars during a steep climb. Pretty much everyone will pull back on the bars and lean over. The lean puts the weight a bit forward and allows better pulling back to offset the hard pedalling. Watch World Cup xc. Hard climbs see the riders forearms are parallel to the ground from pulling back. No one climbs a hard trail sitting bolt upright. No one. Oh. The 9point8 I had on my Bronson a while back had a rebadged Wolftooth remote. Maybe 9point8 are simply making their own copy now?