Standing on the Pegs "Lowers Your Centre of Gravity"?
Posted: Thu Sep 19, 2013 4:36 pm
It's clear that getting up on the pegs gives the rider greater control of the bike off road. Many riders, even knowlegible ones, will claim that it's because you are "lowering your centre of gravity" by placing your weight on the pegs rather than on the seat. I am not a physicist, but this explanation has never washed with me.
Firstly, when folks talk about the centre of "gravity", I believe they actually mean the centre of "mass".
Second, the centre of mass of an assembly of objects, such as a person on a bike, is totally independent of where those objects are connected, or if they are even connected at all for that matter.
Third, standing on the pegs should actually RAISE the centre of mass because there is more mass of the rider distributed higher than when seated.
The dynamics of single-track vehicles is complex & beyond the comprehension of my simple mind, but I have always suspected that, contrary to popular belief, it's actually this HIGHER centre of mass that makes a bike more 'flickable' than a low centre of mass. The reason is because of the increased leverage that the higher centre of mass gives the rider over the bike. I also believe that regardless of whether the overall COM has been raised or lowered, the more important factor is that the COMs of the bike and the rider are 'de-coupled' by standing, thus allowing a more complex & variable relationship with the terrain.
Anyone out there smarter than me able to confirm this, or tell me I'm wrong?
Firstly, when folks talk about the centre of "gravity", I believe they actually mean the centre of "mass".
Second, the centre of mass of an assembly of objects, such as a person on a bike, is totally independent of where those objects are connected, or if they are even connected at all for that matter.
Third, standing on the pegs should actually RAISE the centre of mass because there is more mass of the rider distributed higher than when seated.
The dynamics of single-track vehicles is complex & beyond the comprehension of my simple mind, but I have always suspected that, contrary to popular belief, it's actually this HIGHER centre of mass that makes a bike more 'flickable' than a low centre of mass. The reason is because of the increased leverage that the higher centre of mass gives the rider over the bike. I also believe that regardless of whether the overall COM has been raised or lowered, the more important factor is that the COMs of the bike and the rider are 'de-coupled' by standing, thus allowing a more complex & variable relationship with the terrain.
Anyone out there smarter than me able to confirm this, or tell me I'm wrong?