Certainly fads or styles or whatever have ebbed and flowed over whether or not a noodly frame is undesirable, or how stiff is stiff enough, or if stiff is harsh and uncomfortable, or whatever, but I think Jan is fairly unique in claiming categorically that the right flex is faster, and enough faster that a stiff bike can't be a good "performance" bike.
Im still not quite sure exactly what he is advocating. If its about beneficial interaction between pedaling action and bb flex I don't get why thats called planing. Does somebody here know? On Aug 6, 8:55 pm, Tim McNamara <tim...@bitstream.net> wrote: > On Aug 6, 2012, at 9:32 PM, Steve Palincsar wrote: > > > On Mon, 2012-08-06 at 19:21 -0700, ted wrote: > > >> I wouldn't say a complete kook, but a bit kooky maybe. Certainly he > >> even describes himself a well outside of mainstream thought on these > >> topics. I suspect that "planing" is only mostly settled in the view of > >> those who believe Jan (which I doubt is a majority of any relevant > >> group except perhaps BQ subscribers). > > > Well outside the "stiffer is always better" school of thought, for sure. > > A downright heretic in that respect. As for the rest, don't be so sure: > > they referred to what he calls "planing" as "a lively ride" back in the > > day, and bikes that had it were highly respected and enjoyed. > > True enough. Various aspects of bike frame design have been serially > overemphasized over the course of decades, including BB stiffness, chainstay > length, chainstay and seatstay diameters, etc. The power loss from BB flex > is probably close enough to nil as makes no difference, even with "noodly" > frames. I like mine to be stiff enough to make derailleur rub rare because > it's annoying, but I've never actually been able to feel any power loss from > frame flex. Someone already mentioned Sean Kelly who won monuments and > Classics, the maillot vert, the Vuelta a Espana, etc., on one of the most > notoriously noodly frames ever made, the Vitus 979. If the frame flex > handicapped him, well that's actually just kind of frightening... > > Allan referenced the idea of a bike frame as a spring which is actually > correct. It is a spring. There are several springs on a bike- the frame, > the handlebars, the wheels (especially laterally but also radially), the > saddle, etc. In the case of bars, frame and radial wheel flex the distances > involved are tenths to hundreds of an inch. Lateral wheel flex, especially > the rear wheel, can be relatively large (e.g., 1/8 to 1/4 inch) under normal > use. A lot of these can be quantified with strain gauges, which might be an > interesting study. Can "planing" be objectively measured and compared to the > subjective experience? > > Can all those things affect how a bike feels to ride? Maybe. I think that > most are like the princess and the pea, but some people may be more sensitive > to these sorts of inputs than me. We all have had the experience of "I like > this bike and I don't like that bike." There are a lot of variables that go > into that. Some of those might be exactly the kinds of thing Jan writes > about, some may not. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
