I looked for previous threads with the word "planing" in their titles, but all I came up with was a whole bunch of examples of people who cannot spell "planning."

So, here I am to ask about planing, a term popularized (or maybe invented) by Jan Heine of BQ.

I was reading about it in his book last night, and the relevant section is essentially the same as what is in the link directly above.

I think the basic idea is that a somewhat flexible bike frame can work in resonance with the rider to enhance the efficiency of power output, and a bike that is too rigid, or flexes in the wrong way, can have a deleterious effect. He uses an un-named touring bike with a rigid top tube and more flexible down tube as an example of the latter. The primary symptom he describes is that the rider essentially hits a wall beyond which, if the rider supplies more power, the bike sluggishly responds, the rider's legs start to hurt, etc.

The leg hurting thing caught my interest, because after 10 years on my custom steel bike, I suddenly was experiencing a lot of leg fatigue, which I previously never got. I attributed it to getting older, or impending heart attack or something benign like that, but now I wonder if something on the bike is doing it. I changed the seat-post about 8 months ago, for example, and a few other things...

Anyone have any opinions about this phenomenon? Is it real, or bunk? Does it have any explanatory power? Can a bike that was good or neutral go bad with some sort of change?

I just placed an order with Amazon for a commercial-size case of popcorn. I hope it will be enough.

That totally explains my Lynskey.

Viz., why it feels so horrible after two hours.

I had a long post, but I decided to scrap it.
Look over your bike, and think about the things you changed recently first, then maybe think about if your body is weaker, or the wind was bad that day, or something else.
If it worked for 10 years I don't think it's the bike, unless something drastic changed.

The most drastic was replacing an FSA carbon seatpost with an Enve one.

Sadly, I think it is me.

The only other thing I can think of is that I lost some weight, and maybe the frame is slightly stiffer. More likely is I lost muscle mass (which is apparent from casual visual inspection).

I hope you have Prime return, because this isn't taking off in the way everyone had hoped.

It has picked up. Get the air popper out.

One thing that makes me think there might be something to it is my brief experience with a (2014?) Domane. I rented one while I was waiting on my bike, and getting impatient. I think it had an early version of the isospeed coupler, and by coincidence, the dimensions of the 54 Domane are similar to what I was going to get. I took it for a spin and it really kicked my arse.

Specifically, the iso-speed coupler, which is kind of like an undamped low-travel rear shock, seemed like it was 180° out of phase with my cadence, so once per revolution of the crankset, it would give me a swift kick in the arse, without fail.

Jan cites a stiff aluminum bike they reviewed, that had a variation on this idea, in which there was some sort of elastomer that went between the seatpost and the rear triangle. They had 3 different elastomers, and machined some sort of spacer to get a zero-point. Only one of these four options (the middle elastomer) gave a decent ride.

I've not tried a newer Domane with the adjustable iso-speed coupler, but maybe it lets you change the rebound rate.

IIRC, Tom Ritchey used to say the Road Logic was designed to store power when flexing during the downstroke which it returned as it unflexed. I don't know if that's true, but I can tell you it's a nice bike.

Are you sure it was Jan Heine? I seem to remember it was Grant Petersen who coined the term. I think it's supposed to mean that a bike feels as if it is skimming over bumps similarly to how a flat rock skips over ripples in water when thrown with a spin. Planing can't be measured, at least not yet, so it's worth debating if it is a sane concept at all.

Souplesse / Planing, which type of frames

I rejected the idea of planing out of hand when I first came across a mention of it, but then "What about pogo sticks?" popped into my mind from out of nowhere. Now I don't know what to think.

I would call Jan Heine’s “planing” concept pseudoscience, but I don’t think it rises to that level. It’s totally made-up, handwavy nonsense. Heine has never supplied any data to support this idea, in fact I don’t think he’s so much as suggested what kind of data could support this idea - though actually I have a suggestion there. I remember seeing a GCN video where they went to a new facility that measures system losses by measuring power input and output on what are basically a fancy set of rollers. The rollers even have a variety of surfaces to simulate e.g. smooth roads vs rough cobbles. That’s the kind of facility Heine needs to use to prove his theory… but first he actually needs to formulate it as an actual theory with a definition that could be tested. I think once he did, though, it would sound pretty banal. Frame stiffness, tire pressure, rider position, road surface, other factors, all contribute in various ways to the total system efficiency. What Heine is looking for is a more flexible frame that has better efficiency than a stiff one, right?

Ok, enough Jan bashing. Two things: first, it’s not that hard to imagine a frame with more (ugh) vertical compliance could be more efficient on rough surfaces than one with less. That’s just how suspension works. Second, and to your question: cycling is full of lore about frame materials supposedly “going soft” after a period of hard use. Steel, most famously, but I’ve heard it about aluminum and even carbon fiber. If that were true, yes, a bike could “go bad” as you describe. Luckily, materials going soft is mostly bunk. As far as I’m aware, steel, aluminum and carbon fiber frames can’t lose elasticity through normal use. The little grain that may not be bunk is thatbike frames are structures and parts of those structures could fail. Usually that happens in the form of a crack and a break, in which case your problem is usually much worse than the frame just going soft.

I have owned a lot of bikes. I don't believe I have a perfectly Heine level of understanding what planing is exactly. But I have definitely experienced the elements:

A 1988 Cannondale racer - totally stiff, but upgraded to a Kestrel fork, was not particularly fun to ride - despite having about the stiffest drive train ever. I didn't feel beat up, but I didn't feel actually efficient because pedaling hard feels like there is resistance to perfect pedaling by the inability to put power into the pedals at times because the bike pushed back too hard.

A couple nice lugged and butted steel road frames, that largely road nicely and felt more efficient in most ways - but were something less than ideal. Still slightly better in terms of a spring feel than a variety of carbon I've ridden.

A Vitus 979 skinny tubed aluminum bike. I wanted to like this bike so much, but my impression of riding it was like having a chain made of rubber. Not that bad, but it felt like some of my wattage was just being used up somewhere instead of going to the road.

A Merlin Extralight, that flexes in such a perfectly ergonomic and efficient way it reminds me of when I was a pole vaulter - the bike stores energy and delivers it to the road with perfect efficiency. It smooths the "corners" in my pedaling without losing anything. And it roughs the bumps at the same time.

Can I use this thread to justify my bike expenses? I don't want to bring on any more knee trouble, let alone the heart attack mentioned by Polaris Bark!




;-D

you mean like the ISO Speed found used in the Domane design?

The problem with testing "planing" is that there is no instrument that can measure all of the rider's input vs all of the real world output. A more flexible bike it going to take input not just from the pedals but also the seat and bars. An overly stiff bike is going to resist the smoothest pedaling motion - possibly decreasing rider output prior to any measurement.


The flip side to all of this is that human beings can sense a tremendous number of things at a very fine level. I'm pretty certain I could tell most of my bikes apart by the way they feel on the road. But that doesn't mean that what you are feeling is actually a positive or negative metric of power delivery. It might just be that one feels chocolate and the other feels vanilla, and you happen to prefer chocolate.

But I think it is mighty suspect to conclude that the way pedaling motion is converted to wheels turning on pavement is unaffected by the spring rate and frequency of the device transmitting it.

I had a Scattante DX350 that at times at the right power and cadence, it would seem to build on itself. I don't know if 'planing' or 'souplesse' or whatever term you choose is correct or not, but the behavior was pretty predictable and indeed one of the things I really liked about the bike...When I was strong enough to get above the threshold to make it happen of course.

I think that might be an example (see above with my test ride).

Do you have one of the newer, adjustable ones?

That is not correct. He has published quite a few different planing experiments with power. Here's the first one from Google:

https://www.renehersecycles.com/what-is-planing/

There have been others published in his magazine over time. Americans seem to get wrapped up around the idea that frame flex can be beneficial and that the concept can be formalized and named.

Meanwhile Japanese and French builders, at least, take this as a statement of fact and will provide no end of explanation for finding the ideal specification for "planing" for a given rider's weight and use. French builders and riders have been discussing souple for at least 100 years. Japan heavily after 1964 Tokyo Olympics into their attempt to integrate into the world wide market and European road racing in the 1980s.

You're also out of date on the latest carbon fiber news - turns out the frames/forks can and do "go soft" (stiffness is lost through non-damaging fatigue cycles) through time and use. I'm sure you can find references to TOUR testing or whatever Google decides to show you.

This is well within the bounds of the explanation given for why/how planing happens. The frame and fork are the main aspects but not the only ones. The experiments where all other components are kept the same except the frame/fork make it clear that they are the major contributors but other parts contribute as well. Heine makes it clear in his testing that tires, seatpost, stem/handlebars, and even saddle all have an impact on planing for a given bike.

Otherwise, it's possible and relatively simple to measure everything else with strain gauges. This is what some OEM carbon manufacturers have done. They design the frame with FEA, build prototypes with embedded strain gauges and other measuring devices and test them. It's part of how they are able to create different layups for professional road racers, at times.

the lbs at the time of searching for a gen III & IV didn't offer it.

How exactly is a supple, planing frame supposed to "return power"? What exactly is "returning power"? Is the flexing of the frame resulting in the crank rotating? After all, rotating the crank is the only way to generate power that propels the bike and rider forward.

Also, in this age of marginal gains down to the height of socks and the size of helmets, don't you think if planing was a thing, that Ineos, Visma, UAE, and others would be incorporating it into their bikes ?

Where are the numbers relating stiffness to speed or power?

Jan has interesting ideas, and a lot of them, but he doesn't do good experiments. This makes it hard to evaluate his interesting ideas. I've asked him a few times over the years to explain his experiments but he's declined. So now I just sorta think, "huh, that's an interesting idea" but until someone else replicates his experiments I mostly leave them in the "interesting idea" file. Sometimes that happens, and that's cool; sometimes it turns out that his experiment was bad. So I give him credit for interesting ideas but not dispositive proof.

Maybe that is why you are a Berkeley Prof. and he is selling boutique bike tires. (I think he has a background in atmospheric science of some sort.)

Having said that, I don't think he would claim this idea has already been well-formulated into a testable hypothesis, the kind that would really convince others that the hypothesis is false, or corroborated (Sorry to go all Karl Popper on this.). But I think it does have that potential.

I would suggest, if you really find his ideas interesting, a small collaboration might be in everyone's interest.