Inertia while climbing

[KevinK]

Tom Kellogg says about compact frames (snipped from a previous thread)

<snipped> The big change came when I stood to accelerate or climb. As I stood up, the bike appeared to loose three pounds. The inertia of the bike as I rocked it back and fourth was reduced so much that I felt as though I was on a twelve-pound bike. Interestingly, when seated, a compact frame feels exactly like a traditional design. The compact design has no effect on handling beyond the increases responsiveness during climbing and accelerating.</quote>


That lowering the toptube reduces the inertia of the frame and makes it easier to throw from side to side is an interesting (and I believe supportable)observation. It makes sense that as the mass is moved closer to the rotational center, total system inertia is reduced relative to that center. So if one does alot of out-of-the-saddle climbing, as I do, the mass of components such as seat, post, bars, stem and levers becomes doubly important, as these are the components farthest away from the rotational center of a bike being rocked side to side. Lightening up these components will reduce effects of gravity, as well as reduce overall inertia (albeit only when rocking the bike). And the weight of the contents of your under saddle bag or (heaven forbid) seat mounted water bottles is really killing your climbing ability. Makes me want to rethink my setup, from the top down. I hear a new seat and post calling my name!

Kevin