obrentharris 

If I think I'm either heavy enought or strong enough to bend a top tube I'm deluding myself, perhaps with the exception of the Schwinn Hollywood I commuted on for a couple years.
Brent

georges1

The SLX, the SP, the SL were often some othe most comfortable and supple steel tubes from Columbus , Reynolds had the 531 and the 708 which were their counterparts. For aluminium, I will have various bikes built with different tubings. The Specialized M2 and M4 road frames were some of the harshest road frames to ride on the other hand an Veneto in Altec 2 was a much more supple and pleasurable ride. My Peugeot Prestige in 708 Reynolds is one the most stable bikes I have ever riden and same with my raleigh in 753. But each person is different has different way of feeling the suppleness regarding the tubing and how the bike isplaning or not

Spoonrobot 

This isn't true, we just litigated this on the forum.

To start with, the second link in the OP says:

Which is this test: https://www.renehersecycles.com/what-is-planing/

A double blind test with 3 participants, 2 of which could tell the bikes apart, 1 of which could not.

Otherwise The most referenced blind test is the Magnificent 7 test - which turns out nobody actually read because it's only 1 rider and his determination. Which was that he could tell at the beginning but couldn't tell if he could tell at the end. Because he was both experimenter and participant, a flawed, failed test.

Overall the population of cyclists participating in blind tests is very small, but we know that the majority of tested cyclists are able to pick out the differences between framesets - even if, at times, those differences go against conventional design wisdom.

References:
https://www.bikeforums.net/classic-v...-test-bed.html

https://www.bikeforums.net/classic-v...l#post23083135

https://www.bikeforums.net/classic-v...l#post23083057

https://www.bikeforums.net/classic-vintage/1285619-question-about-aluminum-2.html#post23082938

https://www.bgcycles.com/new-page-1

Here's a list of everyone I was able to find who participated in an openly available blind or double blind test and their perceived ability to determine a difference in framesets:

Riders who can determine compliance of a frame
Mark Vande Kamp
Jan Heine
John Schubert
Imre Barsy

Riders who cannot determine compliance of a frame
Alex Wetmore
jonnyo (from Slowtwitch)

Riders who could tell but were overwhelmed by the trial design:
Alan Coté

It's actually worse than expected, every published blind test I could find, the rider(s) could tell the difference. The lone personal test from Slowtwitch as well as allusions to closed testing from Silca make it clear this isn't a universal experience, in either direction. From a meta-review we would be correct in saying that in a blind test it is much much more likely the participants would be able to tell framesets with common tubing differences apart.

Correct statement: the blind test of steel frames from different tubing has been done and documented, experienced riders. Results = riders could pick tubesets.

If there are any other available public blind or double blind tests, please share.

repechage

In the pre internet age, Bicycle Guide did a tubing “shootout”.

Spoonrobot 

I haven't been able to find much other than these two, referenced above.




This is also a great article/test, but sadly not a blind test: https://www.bikeforums.net/classic-v...-aluminum.html



There are a lot of tubing comparisons in BG but they're not blind tests, which makes sense given that level of rigor wasn't needed for most of their articles, or probably preferred by their readers. I'm always on the hunt for more tests...

mhespenheide 

If I remember correctly, Jan has said that a good recipe for planing is a top tube that's both lighter gauge and smaller diameter than the down tube. He also seems to be fond on standard-diameter tubing, or slightly oversized at most.

rccardr 

Hunh.
Right about 70 rpm and 185 watts, all of a sudden the zen and the unicorns and the clouds and the riding position all come together into one continuous expression of effortless movement. It doesn’t always last a long time- sometimes only for a few minutes- but it is sublime.
Oh, and it has happened on every bike I own as well as the Neo2T trainer.
Is this ‘planing’?

Piff 

As I understand it, this can also be a recipe for speed wobbles.

repechage

the causes can be from any number of sources.
anecdotal experience- I have one bike owned for nearly 5 decades, only speed wobbled once- rebuilt the front wheel with fresh rim and spokes, a training wheel I built from a used rim and Used! Spokes had 30 years on it.
I will blame the wheels.
I have 4 bikes that on a straight downhill stretch won’t wobble when riding “no hands” the vast majority do, very hard to nail down.
‘Severe speed wobble will really impact the confidence in a bike.
the three times I have experienced it, the incidents were started by an unanticipated lateral impact bump.
the worst barreling down Beverly Glen - went from sunny to shade fast and encountered a poor asphalt repair in shadow before my eyes adjusted. Wild ride and not in a good way.
shifting weight back, knee against the vibrating top tube and rear brake only was the way to control.

oh yeah, three of the four no hands stable on a straight descent? French bikes. A vote for 26mm top tube and 28mm down and seat tube?

79pmooney

My first Ti Cycles has speed wobbles that are getting worse as I age and lose both strength and confidence. I've acquired an old race bike that thrives in the fast stuff so it's now not an issue but I did mention it to the builder, Dave Levy last summer and he mentioned he did go with a light top tube. Also that we collectively did a whole lot else wrong, speed-wobble-wise. Short chainstays, long top tube so I could stay at 120 stem, highish BB. (All my call, I hate scraping pedals on turns and love short chainstays that 1) feel rock solid to me on mountain turns and 2( keep the rear tire from skidding on steep stuff out of the saddle. Now I would never go with the short stem. I love the long ones!)

Mad Honk 

An interesting discussion that brings to mind the issue of spring constants in steel tubes. As a golf club fitting professional I use the concept to help golfers produce straighter golf shots and there is a difference in the the orientation of the shaft in flex planes due to that spring constant and tube direction when installed. I suspect the same thing comes into play with tubes in a bike frame. However there is not a tool designed for bike tubes to find the neutral bend plane which would result in a more supple ride as opposed to a more stiff frame build. It is something that has me wondering about the way we build bike frames, and if there could be more design concepts involved like using spring constant methods and positioning of neutral bend planes in tubes opposed to strong planes in the tubes for ride design. I'm pretty sure I am talking in an unfamiliar way for many here but it may be difference in the way frames perform. Contact me offline for more info if interested. Smiles, MH

Kontact 

Titanium bikes from the '90s and '00s with round, straight tubing. Best utilizes the flexibility of titanium as a natural spring.

My Merlin is snappy and smooth.
https://www.spectrum-cycles.com/materials.php

My Vitus 979 aluminum was smooth, but felt like it ate the energy I put into it, which I think is mechanically accurate for aluminum and narrow tubing.


They are rare, but I'd like to see someone test a Slingshot road bike for planing.

Classtime 

I’ve read somewhere of some frame builder(s) who positions his tubes along the axis best suited for flexstiffnessplaningetc. It is similar to aligning the guides on a fishing rod blank.

fender1

I have always been a bit skeptical and remain so but can confirm for me, the light top tube / down tube and stiff rear triangle work very well.

I purchased this frame with no test ride from this add on the Paceline:





Lyon L'Avecaise 700c randonnering bike in like new condition (frame built Jan 2020). This was a custom rando build in 59cm size (c-c) with a 58cm top tube. Made from thin-wall tubing (28mm 7-4-7 top tube, 32mm down tube) for the right flex characteristics according to the Bicycle Quarterly approach. Designed for a 6ft tall rider weighing 210 lbs, made to fit 700x35mm tires (actual width) with fenders. Uses Gran Compe GC610 centerpull brakes for great tire clearance with or without fenders installed. Includes matching Gran Compe mini rando rack to support a front bag. Also include new set of Velo Orange hammered alloy fenders (not yet installed). For reference, the saddle height in the photo is 76cm (crank to top of saddle).

Geometry details:
Top tube length 58cm c-c (level)
Seat tube length 59cm c-c
Seattube angle 72.5 degrees
Headtube angle 72.5 degrees
Head tube length 178mm
BB drop 78mm
Chainstay length 44cm
Fork rake 58mm

After riding it for a summer on the same routes I used my previous bikes, I was able to determine that I was about 1.5 mph faster on average. Not earth shattering but the bike felt much easier to pedal when climbing and keeping it at speed felt easier as well. I also felt that the bike was smoother handling over rough roads.

I sold both of my other bikes (Rivendell A. Homer & Legolas) and orders a second frame, built the same way from Jeff Lyon.




I still think Jan has a tendency to over sell the "planing" thing but am glad for the information as I feel it has made my riding more enjoyable. YMMV.

chain_whipped

Unless I missed it, not a mention here about handlebar compliance, materials, thickness etc..

Next to the wheelset / tires and type, the 'handlebar' is one of the most significant in reflecting a bikes feel.

repechage

might be wrong, but some club manufacturers have the shaft drawn with the wall thickness varying? The OD being a circle, and the ID an oval? Or, not a constant wall thickness anyway.
one tube supplier played with wall thicknesses is an about way, I forget who, and did not catch on obviously.

Mad Honk 

In golf shafts a number of designs have been tried including a seven sided mandrel for the interior of the tube that is then drawn into a round shaft, and even stiffeners added to the inside walls of the shat to stiffen it in carbon fiber shafts. But the Rules of Golf prohibit these products due to the rule that states the shaft should not have unequal bending properties in any plane of the 360* of rotation.
However in mass produced steel tubes it is impossible to have those properties. Each shaft/tube will have a bending plane that is more flexible by a few thousandst of an inch hence the interest in spring constants for me. But it also asks me to wonder if the flexing of bike tubes in similar ways and how when assembled if those flexibility planes in shafts can affect the performance of a frame. Perhaps just a bit of speculation on my part but something that I'm sure bigger minds than mine have investigated in bicycle design. Smiles, MH

mhespenheide 

The stem, too. Back in the 90's, I could tell a distinct difference when I changed from a cast aluminum stem (like Cinelli or 3TTT) to tubular steel (like Ritchey or Tioga, in the style of mountain bikes).

Piff 

Found it! For good reason GCN gathers some flak, but I thought this was a pretty good video:



Also, there's a couple videos from Henry Wildeberry about this, always fun to watch. Note, the guy is just an engineer, not a frame builder.

repechage

Thanks, lots of rules to defeat Golf’s Smokey Yanuck types. Nah, the big minds, they are all thinking carbon now. I have wondered about frames with heavy cold setting to get them into alignment. The manipulating has changed something. Maybe only shows up in a sever crash? Maybe they just speed wobble easier.
good luck for someone to figure that out.

bike tubes from the tube makers often are not straight, this happens often enough that even hobby builders will place the wow or bow so aligned to help keep things
“in control” not drifting to one side.

Trakhak

Seems to me that a frame that twists to the left in response to the pressure applied by the right foot, in the portion of the pedal stroke where power is being applied, must return more or less immediately to center during the "dead" part of the pedal stroke. Unclear how that lateral movement, back to the frame's original position, would transform into power being applied vertically through the left pedal during that pedal's power stroke.

Not saying it's impossible, just that it's hard to think of an obvious simple example of a lateral force contributing to the application of a vertical force.

Come to think of it, if the idea is that some kind of rebound could resupply previously applied force that would contribute to moving the chain, a more obvious move would be to use a shoe with a spongy or springy insole---perhaps a spongy insole (with a carefully controlled rebound rate) sandwiched between stiff inner and outer carbon soles.

(Maybe. Still struggling to grasp how and where the forces are being applied and retrieved during "planing.")

Dunno. Fashions in running shoes have gone from heavier maximalist designs to minimalist (and barefoot!) to super-shoes like the ultra-cushioned Nike Vaporfly in recent years. Will bike manufacturers similarly begin designing modern frames that incorporate elements promoting "planing"?

If planing exists, and genuinely contributes to pedaling efficiency (and thus would contribute to winning bike races), then engineers will eventually begin using computer-aided design to create frames with carbon layups that enable the frames to plane as well as or better than any steel frame ever built.

Unless those engineers discover that planing is intrinsic to the "soul" of steel bikes and, baffled, give up.

repechage

Maddening, but sometimes tap the reply and nada after the software asks me to log on again.

but I saved my post-

some might be from the spring constant, how fast the frame returns in sync or not compared to the power and cadence.
‘I had a bike that just felt it was robbing me of power when climbing. Anecdotal for sure, but not happy. I have decades on a sistership, same import batch as my original, 3 cm smaller, a better bike. And also a lighter gauge seat tube, the original sold off 49 years ago, that is the one anchor point I can confirm.
‘the comment I have made about the Teledyne titan was the frame did Feel as if it was returning as much or more than pedaled into it, But… this was for a given speed, load and cadence, get out of that sweet spot and the bike just felt whippy. If one was in sync and leading, all was good, if one was having to answer an attack? Sometimes not good.

there was one famous maker bike that no one liked. All the employees of the shop test rode it and had the same negative view. And we ALL owned bikes of the same model and brand, of course not adjusted for fit, but it was interesting that all had the same view. The bike eventually sold at a discount, to an owner who probably did not know what he was missing.
construction matters is the lesson, and not always pretty. I have a few French bikes where with the paint off show excess brass, no gaps but too much braze. My hunch was get in, flow the brass fast and get out, limited heat exposure.

Kontact 

Pedal pressure twists the frame, shortening the distance between BB and rear hub. As the pedal pressure decreases the frame unwinds, pushing the rider forward from the hub.

There is no pause in the pressure of the chain from rider to the road, just a change in the amount of pressure. A flexible frame distributes the peak pressure over a longer time period by briefly storing it as frame flex. A very stiff frame runs the risk of peak pressure loss due to tire scrub and resisting a fluid delivery of power.

This always seemed natural and obvious to me after pole vaulting in high school.

Doug Fattic 

I'm a framebuilder that prefers the ride of a .7/.4/.7 thin wall tubing bike frame with a 1" top tube. Full stop. I made my 1st very light frame out of Ishiwata 015 tubing in the late 70's. It was a weight weenie exercise. 015 tubing is even lighter with .6/.3/.6 tubing wall thickness. The whole bike weighed under 16 pounds. What surprised me about the ride of that bike was that it was not whippy or loose/goosy or seemed to flex too much when I rode it. It just rode nicely. I loaned it on one of our training rides to a Cat 2 that rode with us. He was bigger and stronger than me and went on an all out sprint up a fairly steep hill and came back and said the bike flexed too much for him. But I wasn't bigger or stronger - just a decent rider and it certainly worked very well for me.

Let's remember that Jan originally went on a hunt to figure out why he liked the ride of his French bikes (Herse or Singer or both I forget) better than his Bob Jackson. Eventually (as I recall) he came to the conclusion the difference he felt was how thin walled the tubing of the French bikes were compared to the English. And then he has tried to explain why they rode differently and I think this is where all the trouble lies. It is possible people mix up their attitudes with his definition of planing, the way he writes, how they relate to his business. In fact few people have ever ridden a 7/4/7 frame with a 1" top tube. Production companies don't make them because they are harder to manufacturer and the liability is too great. Anything that they make and it breaks can be big trouble. That is why production steel frames were always overbuilt. The exception would be the Raleigh SBDU 753 frames. Of course 753 was made with heavier walls than 7/4/7 so it is possible some of those couldn't be used as an example.

My own frames i've built for myself have 7/4/7 walls with a 1" top tube. I vastly prefer their ride over those with heavier or bigger diameter walls. Even those i've built myself. There is no debate at all in my mind as to what works best for me. And those that have never ridden a light walled bike with a 1" top tube aren't going to persuade me otherwise.

Alan K

Excellent example of “stored and returned energy” in pole vaulting.