Planing

[jclay]

https://www.flickr.com/photos/21624415@N04/15715733237/

Graphical representation, albeit crude, of my take on it, and attempts at explanations of a couple years back, as it relates to the concept of power smoothing. Strain energy as an aid to performance has been well known in some arenas for a long time. I think the difficulty as it relates to bicycles is the non-obvious, non-intuitive flexural modes that could provide the benefit though there was some FEA work a while back that demonstrated them. It has nothing to do with getting more energy out of the system than is applied to it, but everything to do with how the power is generated (affecting peak muscle fiber stress and fatigue) and how the power is applied (smoother power application equalling higher propulsion efficiencies). I think its pretty interesting stuff.

[Andrew R Stewart]

While to some "planning" might be interesting to others the religious like references to it is rather distracting at the least.

I do enjoy much of BQ's content the claims of planning kind of turn me off.

If I must think about it, it seems to me that the possibility of planning, to a degree, is dependent on the rider as well as the bike/frame. So when one says this bike does but that bike doesn't I don't think it applies to every rider. Yet the reference of planning is held in high regard.

Maybe it's a few of the other claims that Jan makes that also don't match my experience that bias me against planning being anything that's important or applicable to others. Andy.

[jclay]

it seems to me that the possibility of planning, to a degree, is dependent on the rider as well as the bike/frame. So when one says this bike does but that bike doesn't I don't think it applies to every rider. Andy.

Absolutely. Just as different golfers prefer different shaft stiffness and different tennis players prefer different string tensions, a given bicycle will behave differently for riders of different weights, strengths and pedal stroke characteristics. The importance is, of course, an individual thing too.

I think Jan and crew generally modify their planing statements with something like "for me", "for us", or "relative to the other bike". I certainly don't subscribe to everything written in BQ, and sometimes things are presented as the only or best way without acknowledging that different rider goals will favor alternate methods. But I can generally sort those sorts of things out foe myself, find what's applicable to me and adjust it accordingly.

[Mark Kelly]

Planing by jmedclay, on Flickr

Graphical representation, albeit crude, of my take on it, <snip>

If you are going for symmetrical waves for both input and output you need to insert a phase delay between them, otherwise the average energy of the output exceeds the input up to about 70 degrees.

[duanedr]

I think different fitness levels have an effect as well as to how 'fast' a bike feels. I have one bike made from standard sized 753 tubing which is very flexible and another steel bike that is made from OS True Temper tubing (much stiffer) and a 3rd made from BIG diameter TI tubing (super stiff) and when I'm weak, I feel like I can maintain higher speeds in similar conditions on the 753 bike than I can on the stiffer bikes with less leg burn. I feel like I bog down or really have to work when I'm weak on the stiffer bikes but when I'm training a lot and I'm stronger, then the stiffer bikes feel better. Maybe I'm imagining it. I don't care enough to put power meter on the bikes and do real testing so...

It's definitely an interesting topic. I find myself building with tubing that is on the lighter end of the scale relative to some of the suggested wall thicknesses for my weight (which is hopefully on it's way back down!).

[jclay]

If you are going for symmetrical waves for both input and output you need to insert a phase delay between them, otherwise the average energy of the output exceeds the input up to about 70 degrees.

Yes, there would be a phase angle between input and output. The two curves I drew aren't an input/output pair though, but rather the different results that I'd expect, at the driven wheel, of the same rider's efforts applied to a stiffer frame as compared to a more flexible one. They could also represent pedal force or muscle fiber tension of each side (with the first half of each curve being one side and the last half being the other).

There is no question that structures, including bicycle frames, store and release strain energy. The only question is whether or not the associated bicycle frame flexural modes (deformation shapes) can benefit propulsion in some way. The possible physical modes arent as intuitively obvious as they are for a golf club shaft or fishing rod and I think that hinders acceptance of the idea.

In discussions about planing over the past couple of years I never saw an explaination of why it would enhance performance. "Getting in synch" didn't identify the actual reason for performance enhancement. I've long (in the sense of the discussion in the usegroups) felt that the ultimate mechanisms would be power smoothing and reduced max muscle fiber tension. If present, as seems reasonable to me, both of those mechanisms would enhance performance.

It isnt any sort of magical framebuilding "touch" thing where this frame or builder "has it", that one doesn't, either. It's just tube stiffness and rider characteristics as they affect the strain energy behavior of a particular tool. Big, powerful golfers can generate longer shots with club shafts that would be excessively stiff for smaller, less powerful players. There are lots of analogous situations in the physical world.

[Mike Mcdermid]

It isnt any sort of magical framebuilding "touch" thing where this frame or builder "has it", that one doesn't, either

this is because it sounds like complete bollocks to be frank

[steve garro]

If you are going for symmetrical waves for both input and output you need to insert a phase delay between them, otherwise the average energy of the output exceeds the input up to about 70 degrees.

I am familiar with bar napkin engineering but 12pk box engineering…….man, that's pro!
Pen, even, no erasing - shows fortitude and confidence.

- Garro.

[shand]

There needs to be some kind on interweb thing that shuts down the www for 24hrs anytime someone mentions 'planing' on a bike forum.

[Mike Mcdermid]

planking on a plne.jpg

here is a good effort its a man planing

planing1.jpg

[Too Tall]

I can do that. Seems harsh considering. How about we just file this under "School of funny walks"?

There needs to be some kind on interweb thing that shuts down the www for 24hrs anytime someone mentions 'planing' on a bike forum.

[jclay]

this is because it sounds like complete bollocks to be frank

"Bollocks" and caricatures are weak retorts...unless one simply wants to derail civil, constructive conversation; they're effective at that. A rational explanation as to why you think it's not possible would be a more useful approach.

[Mike Mcdermid]

"Bollocks" and caricatures are weak retorts...unless one simply wants to derail civil, constructive conversation; they're effective at that. A rational explanation as to why you think it's not possible would be a more useful approach.

It was boring last time round mate....edited thank Christ theres an ignore feature on the forum

[Craig Ryan]

I've seen a remarkable increase in planing on the bikes I make, paint, touch, or in some cases look at on the internet. I've got the proof, but no one else is sensitive enough, or in tune to the necessary degree to feel it. I'd make a drawing, but I can't get the 4th dimension to render on a napkin. Oh, orange bikes plane sooner.

[zank]

White bar tape is pro. It must help with planing.

[hmbatrail]

White bar tape is pro. It must help with planing.

Unless you have a zero offset seatpost. Which as we all know is certainly un-PRO and, thus, unplanable.

[zank]

Totally. It can be somewhat offset though with colored cable crimps.

[steve garro]

Totally. It can be somewhat offset though with colored cable crimps.

Do disc brakes plane?

- Garro.

[zank]

Absolutely. Like little jet turbines.

[JLP]

Planing? What is it?

It's that conversation over in the bike forum, but that's not important now.