planing

[thwart]

Yep, you've heard it referred to here...

… and across the hall as well, perhaps a bit derisively.

Well, here's Mr. Heine's latest description of what we should all want our bikes to do:

http://janheine.wordpress.com/2014/12/31/the-biomechanics-of-planing/

[weaponsgrade]

Did they ever mention the specific tubing that was used in the double blind test? I've spent lots of time on old classic steel, modern heat-treated steel, ti, and carbon. The old steel bikes I've ridden felt like dogs compared to the other stuff. I find my new steel and ti bikes to have very similar ride characteristics. I'm not sure if the differences are b/c of "planing", geo, tires, or whatever, but that's my experience.

[oldpotatoe]

Yep, you've heard it referred to here...

… and across the hall as well, perhaps a bit derisively.

Well, here's Mr. Heine's latest description of what we should all want our bikes to do:

http://janheine.wordpress.com/2014/12/31/the-biomechanics-of-planing/

really, I wonder why? Channeling Grant Peterson....

[1centaur]

I have said before that it makes no sense to say that frame flex is inherently returned as forward motion (i.e., pushing the chain forward). There is a big difference between saying that frame flex does not dissipate energy as heat and saying a vaguely sideways motion becomes a forward impetus when the sideways motion reverses.

On the other hand, it is not irrational to say that some flex feels more comfortable to the muscles than no flex. We are forcing our very variable biomechanical limbs around a relatively fixed circle, and depending how beautifully we ourselves are able to execute the pedal stroke (much determined by nature rather than nurture) there will be times when we are "pushing against a wall" as the article suggests. To reduce the muscle fatigue from such useless motion, some flex would seem to be desirable, but, a la Speedplay comments, there's a trade-off between how much we want and how much we can live with to make our strokes maximally efficient. Further, that amount depends on seasonal variations of fitness and temperature, so one cannot make a truly highly optimized custom frame for a given rider's style.

Perhaps an unintended irony of the article, given its source, is that the more important it is to target flex towards optimal power input over time, the more carbon fiber bikes should be seen as the answer, rather than steel bikes, because they are far more manipulatable for flex direction than steel. Engineering could easily adapt to the results of biomechanical studies on this topic and carbon layups could be adjusted. If, and it is a big if, steel's natural flex is somehow more efficient for muscles than a dumb-ass quest for stiffness from CF bike makers, history will evolve to show that quest was brief and quickly overcome. To think that steel "naturally" has the magic right amount of flex seems fanciful, if not delusional.

[eddief]

it seems in earlier discussions, planing was described as a sweet spot reached by just the right combination of material, geometry, frame, fork, parts, rider weight, and what that rider's brain would identify as planing. And that spot was incredibly elusive because all the variables were hard to control in a way that you knew, in the end, you'd end up with a bike that planed. I'd say that planing exists, but is mostly an accident that results in an ah ha moment that we can only hope will happen one time when we get on that next bike.

The only time I felt is was on a really cheap Fuji Touring.

[rwsaunders]

Tom starts off the new year stirring the pot. What's next, a discussion on vertical compliance? :cool:

[eddief]

and have noticed my vertical compliance is not what it used to be.

[Rueda Tropical]

Perhaps an unintended irony of the article, given its source, is that the more important it is to target flex towards optimal power input over time, the more carbon fiber bikes should be seen as the answer, rather than steel bikes, because they are far more manipulatable for flex direction than steel. Engineering could easily adapt to the results of biomechanical studies on this topic and carbon layups could be adjusted. If, and it is a big if, steel's natural flex is somehow more efficient for muscles than a dumb-ass quest for stiffness from CF bike makers, history will evolve to show that quest was brief and quickly overcome. To think that steel "naturally" has the magic right amount of flex seems fanciful, if not delusional.

Heine has given rave reviews to carbon bikes he has reviewed so it would seem although he rides steel he is not averse to other materials. It would not be easy (maybe impossible unless you have very large piles of cash) to get a custom carbon frame and fork with custom layed up tubes to the specs of the sort of bike he prefers. That's left steel by default as the cost-effective material of choice.

But we are seeing more carbon bikes and wheels that are starting to look more and more like the sort Heine might prefer coming to market. Wider wheels, fatter tires, longer and more compliant "endurance geometry". So carbon choices are widening and are getting more like steel in the ability to get more then just a narrow range of bike type.

[numbskull]

This makes sense to me. Nobody would have trouble believing too soft a frame could lead to inefficiencies, why would it be news that too stiff a frame could do the same?

I think it is likely that force delivered through a pedal and stored in a frame is returned back through the pedal later in the pedaling cycle. In a full mechanical system this would probably lead to some loss of energy (via material friction/heat/etc) but a bicycle engine is a biological system and biology is the major determinant of the peak speed and force that can be delivered over time. Slowing and lengthening that delivery (by storing some) very likely has some biological advantage in the form of more efficient muscle contraction (more isotonic than isometric) and less ligament strain.

I agree, however, that graphite offers more engineering opportunity than steel to achieve a perfect balance and the ideal balance likely varies dramatically rider to rider (or even for the same rider during a ride).

[fuzzalow]

Dunno about any of this. Strikes me as a philosophical or metaphysical argument akin to how many angels can dance on the head of a pin. The tangential point made about "pushing against a wall" falls short because the cranks are still capable of turning, so no, it is not like the wasted effort in the futility of "pushing against a wall".

However, in fairness, I have no problem acknowledging that humans can feel very minute and subtle changes so whatever quality Mr. Heine is writing about might well be possible to discern. And if there is preference for one type of feel over another that's perfectly alright. However, I don't think it means diddly to the process of riding a bike as far as power or results. Subtlety in feel or technique means very little in powering a bike which is not a fine motor skill activity. In contrast to Itzak Perlman on a violin or Yo Yo Ma on a cello where the subtlety in feel or technique means all the difference in the world between what they can do versus what the common practitioner can do with those instruments.

If you wanna know what "planing" feels like, get the bike setup correctly for fit & position. Get the balance right so that the rider perches totally relaxed on top of the bike so that the bike runs freely beneath the rider. Almost like the way a surfer concurrently rides the board and the wave in concert with the positioning of his own body mass atop the board. Nowhere near as challenging as a surfer but the idea is similar. That, to me, is "planing" - feels like flying close to the ground. No effort in the position but with easy power into the cranks - like a good golf swing: balance in support of kinetics.

Once you know what that is, that's when use of terms like "planing" just bring a smile.

[numbskull]

Here is a link to the earlier article http://janheine.wordpress.com/2014/11/23/what-is-planing/

[makoti]

Dunno about any of this. Strikes me as a philosophical or metaphysical argument akin to how many angels can dance on the head of a pin.

Six. Never understood why this is so difficult.

[93legendti]

Slingshot. Fastest bike I ever rode. Climbed like a Sherpa.

[ElvisMerckx]

The 'plane-believers' have invested a lot of words over the years in an attempt to explain a perception. I've read a bunch of it, including the linked article, and all I walk away with is "flexy is okay (with the following qualifiers: only sometimes and to an extent, but it's not always bad at least, got that?)."

So is this cult-like group think or is there any measurable, usable engineering data that frame builders and industry can leverage to make better bikes?

And no, I don't consider a double-blind road test with results like "sensation of pleasant warmth in our legs" and "minimal mental effort" to be significant data.

[Doug Fattic]

As I understand it, Jan went on a hunt as to why he liked his old Rene Herse and Alex Singer bicycles better than other bicycles. In his search he measured their geometry and examined their components. Eventually what he found was that the French masters used especially thin walled tubing. Those old builders described it as "three/tenths”. This is not a definition framebuilders use today. I’ve understood it to mean the middle of the tubes were 0.3mm thick. Now normally the difference in butting thickness on a bicycle tube is .3mm so for example Columbus SL main tubes are .9/.6/.9mm thick and SP is 1.0/.7/1.0mm. The lightest steel tubes commonly available today is .7/.4/.7mm so what Herse and Singer built with was really really thin and how they ride should not be confused with classic frames from England for example.

Probably very few Paceliners have ever ridden a steel bicycle frame with a 1” top tube and 1 1/8” down tube with wall thicknesses of .7/.4/.7mm. While tubing this light could be special ordered in the past it wasn’t generally available until Reynolds came out with its heat treated 753 tubing in the 70’s. The heat treatment made it less easy to dent. A builder had to pass a test in order to be able to buy it. A little later Tange came out with its Prestige line. Thin walled heat treated tubing was almost never used on a production frame because it requires more care to build and keep aligned than their heavier cousins. By the way Prestige tubing came in all wall thicknesses from thin to thick and in many different diameters. Production exceptions would be 753 Raleighs and some late 80’s Japanese frames. Bill Davidson made quite a few in the late 80’s early 90’s in his semi-custom shop that had a number of employees. Custom framebuilders probably made them only for their smaller customers and may not have used it at all because it wasn’t in line with what they believed. Which brings us to the next point.

Their is a kind of philosophical divide in the biking community like Republican/Democrat or Shia/Sunni or racer/not racer. And that is stiffer is better. Or not. Jan belongs in the “or not” camp.

I’m a framebuilder that loves really light tubing standard diameter tubing. But it isn’t for everybody. In 1978 I built a frame for myself out of Ishiawata tubing that was .6/.3./.6 (model 015). When I built it up into an entire bicycle it weighed somewhere between 15 and 16lbs. If I used some of todays parts I’m sure I could get it down to 13lbs. I expected it to be really whippy and flexible but it wasn’t under my modest power output. I loved it. When I loaned it out to others to test ride their opinions on the quality of the ride varied a lot. Some complained it flexed too much and others loved it too. This range still divides us into 2 camps. I want to emphasize that my like of this tubing really has nothing to do with how much it weighs or makes the bicycle weigh. It is not about weight but how it feels. It has the right amount of stiffness flexibility to feel right to me. My present frame is made from 7/4/7 standard diameter (1” top tube) tubes.

So I believe that thin walled steel tubing has the best feeling ride for some people from my experience building many frames over many years. I am not a physicist so I don’t why. Planing is a theory that attempts to explain why. The problem for me is that when some reject the theory of planing, they are also rejecting the underlying value of thin walled tubing itself. That is unfortunate. The fact that I like thin walled tubing better for me doesn’t mean it is better for everyone or that planing is the reason why it works. I’ve also heard that a frame’s slight flex gives the muscles a bit of rest so they can go harder or longer. I don’t know if that is true either. Whatever the reason, a frame I’ve made for myself that has 7/4/7 tubing I like a lot more than one that is 9/6/9. As always, YMMV.

[FlashUNC]

The 'plane-believers' have invested a lot of words over the years in an attempt to explain a perception. I've read a bunch of it, including the linked article, and all I walk away with is "flexy is okay (with the following qualifiers: only sometimes and to an extent, but it's not always bad at least, got that?)."

So is this cult-like group think or is there any measurable, usable engineering data that frame builders and industry can leverage to make better bikes?

And no, I don't consider a double-blind road test with results like "sensation of pleasant warmth in our legs" and "minimal mental effort" to be significant data.

I think we're in the same boat. Every one of these I read I come away with the same impression: Flexy is okay, until it isn't. Stiff is okay, until it isn't. And that "it isn't" threshold varies for every rider.

The "warmth in the legs" crap is just that.

[Waldo]

Planing is having much better legs than you anticipated.

[Ken Robb]

As I understand it, Jan went on a hunt as to why he liked his old Rene Herse and Alex Singer bicycles better than other bicycles. In his search he measured their geometry and examined their components. Eventually what he found was that the French masters used especially thin walled tubing. Those old builders described it as "three/tenths”. This is not a definition framebuilders use today. I’ve understood it to mean the middle of the tubes were 0.3mm thick. Now normally the difference in butting thickness on a bicycle tube is .3mm so for example Columbus SL main tubes are .9/.6/.9mm thick and SP is 1.0/.7/1.0mm. The lightest steel tubes commonly available today is .7/.4/.7mm so what Herse and Singer built with was really really thin and how they ride should not be confused with classic frames from England for example.

Probably very few Paceliners have ever ridden a steel bicycle frame with a 1” top tube and 1 1/8” down tube with wall thicknesses of .7/.4/.7mm. While tubing this light could be special ordered in the past it wasn’t generally available until Reynolds came out with its heat treated 753 tubing in the 70’s. The heat treatment made it less easy to dent. A builder had to pass a test in order to be able to buy it. A little later Tange came out with its Prestige line. Thin walled heat treated tubing was almost never used on a production frame because it requires more care to build and keep aligned than their heavier cousins. By the way Prestige tubing came in all wall thicknesses from thin to thick and in many different diameters. Production exceptions would be 753 Raleighs and some late 80’s Japanese frames. Bill Davidson made quite a few in the late 80’s early 90’s in his semi-custom shop that had a number of employees. Custom framebuilders probably made them only for their smaller customers and may not have used it at all because it wasn’t in line with what they believed. Which brings us to the next point.

Their is a kind of philosophical divide in the biking community like Republican/Democrat or Shia/Sunni or racer/not racer. And that is stiffer is better. Or not. Jan belongs in the “or not” camp.

I’m a framebuilder that loves really light tubing standard diameter tubing. But it isn’t for everybody. In 1978 I built a frame for myself out of Ishiawata tubing that was .6/.3./.6 (model 015). When I built it up into an entire bicycle it weighed somewhere between 15 and 16lbs. If I used some of todays parts I’m sure I could get it down to 13lbs. I expected it to be really whippy and flexible but it wasn’t under my modest power output. I loved it. When I loaned it out to others to test ride their opinions on the quality of the ride varied a lot. Some complained it flexed too much and others loved it too. This range still divides us into 2 camps. I want to emphasize that my like of this tubing really has nothing to do with how much it weighs or makes the bicycle weigh. It is not about weight but how it feels. It has the right amount of stiffness flexibility to feel right to me. My present frame is made from 7/4/7 standard diameter (1” top tube) tubes.

So I believe that thin walled steel tubing has the best feeling ride for some people from my experience building many frames over many years. I am not a physicist so I don’t why. Planing is a theory that attempts to explain why. The problem for me is that when some reject the theory of planing, they are also rejecting the underlying value of thin walled tubing itself. That is unfortunate. The fact that I like thin walled tubing better for me doesn’t mean it is better for everyone or that planing is the reason why it works. I’ve also heard that a frame’s slight flex gives the muscles a bit of rest so they can go harder or longer. I don’t know if that is true either. Whatever the reason, a frame I’ve made for myself that has 7/4/7 tubing I like a lot more than one that is 9/6/9. As always, YMMV.

Thanks for this insight. It makes sense to me. I think similar effects can be felt in tennis rackets and golf clubs. A big strong hitter likes stiff frames and shafts because they efficiently transfer the racket/clubhead speed/power they can generate while flex dissipates a bit. OTOH less powerful "swingers" get a little more "pop" in their shots from more flexible rackets and shafts. We sometimes call this "trampoline effect".
Going a step farther in this analogy: Golf balls come in at least 3 different compression ratings like 80,90,100. A weak hitter will do best using 80 compression because he can compress it and benefit from the resulting rebound. This same player will get little to no compression of a 100 ball so it will feel like hitting a rock and won't travel as far. A big hitter smacking an 80 ball will feel like he hit something spongy with no click and he won't get the same velocity/distance on his shots.

[charliedid]

Plane as day.

[Ken Robb]

many have tried to 'splain this before.

[sg8357]

For Doug, A 1986 Ellis Briggs made with Reynolds 531 Professional.

531Pro has 531 main tubes drawn thinner than standard 531 and 753R rear stays.

[fuzzalow]

Six. Never understood why this is so difficult.

HaHa! Thanks for setting me straight! I've been wasting all this time and effort on working out a bad proof because some guy told me the answer was 42!

All kidding aside, all props to Jan Heine for taking a swing at something difficult and sharing his approach and views on the subject. It is much too easy to comment from here in the peanut gallery and although I may not agree, or understand fully, what he's hypothesizing, I'll never take a cheap shot at him for trying!

Thanks to Mr. Fattic also for his writeup and the backstory of Jan's calling in unraveling the mystery.

[skijoring]

Credits and debits.

[1centaur]

I'll throw something into the mix for future searching.

On a Computrainer, I have found the stiffer the bike the better, period. Clenched in the trainer one can look down and see the BB sway to the side on powerful strokes. A trainer, with no benefit from tires and no effort relief from sideways wheel movement, would seem to be the ultimate example of "pushing against a wall," yet it is clearly (to my perception) "easier" to pedal up Mt Ventoux, et. al., on a stiff aluminum bike (CAAD 9 or Klein) than a flexible steel bike (LeMond Zurich) or flexible Ti/Carbon bike (Colnago CT-1). I have long thought a Big Leg Emma or a Gaulzetti might be the ultimate trainer bike.

One might imagine that the "system" of frame flex plus tire effect plus wheel movement creates the "planing" while isolating the frame flex alone breaks down the system. One could speculate either way.

[Doug Fattic]

For Doug, A 1986 Ellis Briggs made with Reynolds 531 Professional. 531Pro has 531 main tubes drawn thinner than standard 531 and 753R rear stays.
Wow, thanks for posting the picture! Ellis-Briggs built true custom frames one at a time. For those that don’t keep track of a random framebuilder’s history, I apprenticed there in the 70’s. Sadly Andrew the young journeyman framebuilder when I was there died suddenly this fall while I was in Ukraine. He, like me, learned from Jack Briggs that learned from his father Tom. Andrew had started to teach Paul how to make frames so their long tradition of building on the premises could continue but they still had a ways to go before his unexpected passing. Paul is now coming to take my 3 week January framebuilding class. Since my methods are based on my training it only makes sense I teach him. So the circle of knowledge will go back to its source.

[fogrider]

I've ridden many steel bikes, a fair number of ti bikes, a few alum bikes, a few carbon bikes, and a few scandium bikes. I will say, I like stiff, light bikes. but I do love the way my steel ron cooper climbs and that frame is about 4.5 pounds. but together with lightweight bits and carbon rims, its a 17.5 pound bike. but I certainly don't think there is much flex in the cooper. https://www.flickr.com/photos/72776081@N03/

[Ti Designs]

Sorry to ask such stupid questions, but if Tv clockwise returns power, what is Tv CCW doing? The ratcheting mechanism in the wheel only works in one direction. What we have here is half planing at best...

[JMacII]

These guys would make great audiophiles.

[sg8357]

These guys would make great audiophiles.

You are on to something there, maybe planing only happens when the tubes
are installed in a certain direction ? Tubes should be built up in the direction
they were drawn, so the harmonic resonances dissipate front to rear when
riding.*

pat pending, this means you Specialized.

[oldpotatoe]

These guys would make great audiophiles.

or golfers.

[fuzzalow]

The biggest stumbling block of what Mr. Heine falls prey to is IMO conflating the temporal elusiveness of a feeling of "better" with a hypothesis that this "planing" sensation is more efficient or somehow a better transmission of power. All then loosely justified by vague biomechanical speculation.

If a rider likes the feel of a certain response a frame has to pedaling effort, that's all the reason necessary.

I have no way of knowing if frame flex is good or bad other than for avoiding something that is structurally unsound. Duh! All frame flex does is change the amplitude and the timing of the pedal stroke force distribution through the drivetrain. This in keeping with Newton's Conservation of Energy that, as far as I know, has never been disproven.

Not trying to get geeky but I was taught this stuff about Newton in grammar school so there must have been a reason for doing that. Now I know; it was to rebut a future bike forum discussion about "planing".

[soulspinner]

As I understand it, Jan went on a hunt as to why he liked his old Rene Herse and Alex Singer bicycles better than other bicycles. In his search he measured their geometry and examined their components. Eventually what he found was that the French masters used especially thin walled tubing. Those old builders described it as "three/tenths”. This is not a definition framebuilders use today. I’ve understood it to mean the middle of the tubes were 0.3mm thick. Now normally the difference in butting thickness on a bicycle tube is .3mm so for example Columbus SL main tubes are .9/.6/.9mm thick and SP is 1.0/.7/1.0mm. The lightest steel tubes commonly available today is .7/.4/.7mm so what Herse and Singer built with was really really thin and how they ride should not be confused with classic frames from England for example.

Probably very few Paceliners have ever ridden a steel bicycle frame with a 1” top tube and 1 1/8” down tube with wall thicknesses of .7/.4/.7mm. While tubing this light could be special ordered in the past it wasn’t generally available until Reynolds came out with its heat treated 753 tubing in the 70’s. The heat treatment made it less easy to dent. A builder had to pass a test in order to be able to buy it. A little later Tange came out with its Prestige line. Thin walled heat treated tubing was almost never used on a production frame because it requires more care to build and keep aligned than their heavier cousins. By the way Prestige tubing came in all wall thicknesses from thin to thick and in many different diameters. Production exceptions would be 753 Raleighs and some late 80’s Japanese frames. Bill Davidson made quite a few in the late 80’s early 90’s in his semi-custom shop that had a number of employees. Custom framebuilders probably made them only for their smaller customers and may not have used it at all because it wasn’t in line with what they believed. Which brings us to the next point.

Their is a kind of philosophical divide in the biking community like Republican/Democrat or Shia/Sunni or racer/not racer. And that is stiffer is better. Or not. Jan belongs in the “or not” camp.

I’m a framebuilder that loves really light tubing standard diameter tubing. But it isn’t for everybody. In 1978 I built a frame for myself out of Ishiawata tubing that was .6/.3./.6 (model 015). When I built it up into an entire bicycle it weighed somewhere between 15 and 16lbs. If I used some of todays parts I’m sure I could get it down to 13lbs. I expected it to be really whippy and flexible but it wasn’t under my modest power output. I loved it. When I loaned it out to others to test ride their opinions on the quality of the ride varied a lot. Some complained it flexed too much and others loved it too. This range still divides us into 2 camps. I want to emphasize that my like of this tubing really has nothing to do with how much it weighs or makes the bicycle weigh. It is not about weight but how it feels. It has the right amount of stiffness flexibility to feel right to me. My present frame is made from 7/4/7 standard diameter (1” top tube) tubes.

So I believe that thin walled steel tubing has the best feeling ride for some people from my experience building many frames over many years. I am not a physicist so I don’t why. Planing is a theory that attempts to explain why. The problem for me is that when some reject the theory of planing, they are also rejecting the underlying value of thin walled tubing itself. That is unfortunate. The fact that I like thin walled tubing better for me doesn’t mean it is better for everyone or that planing is the reason why it works. I’ve also heard that a frame’s slight flex gives the muscles a bit of rest so they can go harder or longer. I don’t know if that is true either. Whatever the reason, a frame I’ve made for myself that has 7/4/7 tubing I like a lot more than one that is 9/6/9. As always, YMMV.

I dig my .7/.4/.7 foco frame even though Im 167 pounds. Ive ridden stiffer bikes but with all the bad roads near where I ride, too stiff bikes seem less planted on broken pavement.

[HenryA]

I've always thought of the ideal frame as being one that kept the tires on the ground while keeping the wheels adequately aligned to provide accurate and steady handling.

One extreme of frame stiffness would be where the wheels stay almost perfectly aligned but the tires are bouncing off the road surface. I'd call that bike choppy or harsh. The other extreme is where the wheels get out of line enough to screw with the steering/stability of the bike. It doesn't go right where you aim it and feels like its fighting itself (it is). I'd call that bike flexy or sloppy.

I don't think any of this matters on a trainer. I can make any bike's bottom bracket and rear triangle flex on a trainer. And there is no trade off for handling or comfort on a trainer. It does matter on the road when the bike is pushed hard and the grip of the tires matters to both your intended path and the transfer of power to the pavement.

Comfort figures into this as well but its maybe secondary to the bike's ability to put the power to the pavement and go in the desired direction, perhaps more a factor of tolerance or lack of tolerance to discomfort by the rider.

Stiffness is a great measure for use by magazine writers to prove whatever point they want to make. Its an attempt to objectify something that's not really the end performance measure of a bike frame, but they can put a number to it. As if basketball players must be better because they are taller.

[Ti Designs]

I'm still trying to wrap my head around this idea that flex in a system can increase power output at the end node. My model is based on the sum of the instantaneous torque (the amount of force tangential to the crank) all the way around. There is a loss when the force applied causes flex, the question is if the sum of the forces is greater - we're talking area under the curve, not highest point on the curve.

It just so happens that I am building a fitting bike similar to the Retul Muve (Specialized is invested in Retul, it's only a matter of time before I hear from their lawyers) to study the forces involved with pedaling a bike. Right now the bottom bracket block is a solid aluminum block that holds a bottom bracket, but it wouldn't take too much effort to add a 2-axis pivot and some springs to simulate a stiffer or less stiff frame.

There is another side to this, which is the biomechanics side. Frame flex limits maximum tension on the muscles, which is when damage happens and what causes fatigue. What if they are simply saying that a stiff frame, while more efficient, takes a greater toll on the muscles? Anything that has to do with the body is harder to test for...

[thirdgenbird]

What if they are simply saying that a stiff frame, while more efficient, takes a greater toll on the muscles?

That is sort of how I took it.

[SPOKE]

that is sort of how i took it.

+2

[El Chaba]

As I understand it, Jan went on a hunt as to why he liked his old Rene Herse and Alex Singer bicycles better than other bicycles. In his search he measured their geometry and examined their components. Eventually what he found was that the French masters used especially thin walled tubing. Those old builders described it as "three/tenths”. This is not a definition framebuilders use today. I’ve understood it to mean the middle of the tubes were 0.3mm thick. Now normally the difference in butting thickness on a bicycle tube is .3mm so for example Columbus SL main tubes are .9/.6/.9mm thick and SP is 1.0/.7/1.0mm. The lightest steel tubes commonly available today is .7/.4/.7mm so what Herse and Singer built with was really really thin and how they ride should not be confused with classic frames from England for example.

Probably very few Paceliners have ever ridden a steel bicycle frame with a 1” top tube and 1 1/8” down tube with wall thicknesses of .7/.4/.7mm. While tubing this light could be special ordered in the past it wasn’t generally available until Reynolds came out with its heat treated 753 tubing in the 70’s. The heat treatment made it less easy to dent. A builder had to pass a test in order to be able to buy it. A little later Tange came out with its Prestige line. Thin walled heat treated tubing was almost never used on a production frame because it requires more care to build and keep aligned than their heavier cousins. By the way Prestige tubing came in all wall thicknesses from thin to thick and in many different diameters. Production exceptions would be 753 Raleighs and some late 80’s Japanese frames. Bill Davidson made quite a few in the late 80’s early 90’s in his semi-custom shop that had a number of employees. Custom framebuilders probably made them only for their smaller customers and may not have used it at all because it wasn’t in line with what they believed. Which brings us to the next point.

Their is a kind of philosophical divide in the biking community like Republican/Democrat or Shia/Sunni or racer/not racer. And that is stiffer is better. Or not. Jan belongs in the “or not” camp.

I’m a framebuilder that loves really light tubing standard diameter tubing. But it isn’t for everybody. In 1978 I built a frame for myself out of Ishiawata tubing that was .6/.3./.6 (model 015). When I built it up into an entire bicycle it weighed somewhere between 15 and 16lbs. If I used some of todays parts I’m sure I could get it down to 13lbs. I expected it to be really whippy and flexible but it wasn’t under my modest power output. I loved it. When I loaned it out to others to test ride their opinions on the quality of the ride varied a lot. Some complained it flexed too much and others loved it too. This range still divides us into 2 camps. I want to emphasize that my like of this tubing really has nothing to do with how much it weighs or makes the bicycle weigh. It is not about weight but how it feels. It has the right amount of stiffness flexibility to feel right to me. My present frame is made from 7/4/7 standard diameter (1” top tube) tubes.

So I believe that thin walled steel tubing has the best feeling ride for some people from my experience building many frames over many years. I am not a physicist so I don’t why. Planing is a theory that attempts to explain why. The problem for me is that when some reject the theory of planing, they are also rejecting the underlying value of thin walled tubing itself. That is unfortunate. The fact that I like thin walled tubing better for me doesn’t mean it is better for everyone or that planing is the reason why it works. I’ve also heard that a frame’s slight flex gives the muscles a bit of rest so they can go harder or longer. I don’t know if that is true either. Whatever the reason, a frame I’ve made for myself that has 7/4/7 tubing I like a lot more than one that is 9/6/9. As always, YMMV.

Thanks for this informative post...

Some years back, I had the opportunity to ride an unusual Alex Singer from the mid 1970's......unusual in that it wasn't a camper or randonneuse, but a "racer". It was very light for the -era-about 18 lbs as aI recall. Now, it was equipped with a titanium bottom bracket and a few other bits, but it was mostly the standard French assortment of the day-simplex SLJ's, Stronglight 93 crankset, Mafac Competition centerpulls, etc...So, the frame was pretty light. It really did have a great feel on the road. I wasn't about to stomp on the pedals on a borrowed bike, but nor did I notice any undue or objectionable flexiness anywhere. It does give some insight into the devotedness of the following of the really nice French bikes of the era....