Apologies if someone already mentioned this, but... Long before I ever heard the name Jan Heine or the term "planing," It was Grant Petersen who first brought the phenomenon to my attention. The 1992 Bridgestone catalog has an article on p. 34 explaining why they preferred skinny tubing on their bikes when the rest of the world was going OS. It's called "The Benefits of a Little Frame Flex" and compared it to jumping higher on a sprung wooden floor as opposed to a hard concrete floor. One quote: "A bike frame flexes under the pressure of pedaling, and, as it recovers from the flex, releases some of that energy to help you go." I've always wondered why Grant changed his mind and went with stiff OS tubing on Rivendell bikes.
Cheers, Ryan in Albuquerque On Aug 7, 2012, at 6:28, ted <ted.ke...@comcast.net> wrote: > "Jan has tried to explain that, mainly he came up with the term when > he was first thinking about the issue, IIRC. He borrowed the term > from boating." > > Interesting. It is precisely because of the terms use in boating that > I find his application perplexing and a source of confusion. > When a boat planes it is running more over the water than through it. > It's also a phenomena that requires a minimum speed to realize, and > there is a hump in resistance before reaching planing speeds where > resistance is greater than it is after you get the boat up and > planing. Seems like it just doesn't fit as a label for a desirable > oscillating bottom bracket motion. > > On Aug 6, 10:41 pm, Tim McNamara <tim...@bitstream.net> wrote: >> Jan has tried to explain that, mainly he came up with the term when he was >> first thinking about the issue, IIRC. He borrowed the term from boating. >> >> One problem is that what's stiff to Jan and Mark might be noodly to me, >> since I am probably 60 lbs heavier and 6" taller than they are. My >> "fastest" bike (according to my average speeds, anyway, but again there are >> too many uncontrolled variables) is my Ritchey, which also has the stiffest >> BB due to the ovalized seat tube. >> >> On Aug 6, 2012, at 11:42 PM, ted <ted.ke...@comcast.net> wrote: >> >> >> >> >> >> >> >>> 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 >>> athttp://groups.google.com/group/rbw-owners-bunch?hl=en. > > -- > 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. > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. 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