Souplesse / Planing, which type of frames
 

A question that keeps on bugging me: which frames, materials and tubing lead to more souplesse / planing, and which ones don't? Over the years I started to enjoy the feeling of souplesse. Which direction should I go on next purchases?

This morning I read a comment by beabear444 about Vitus 979 that they are springy and also have souplesse / planing. I had no idea.
https://www.bikeforums.net/classic-v...-aluminum.html

I have ridden a classic Look with carbon tubing and lugs, and found that smooth but dead, not springy or with souplesse / planing. I was expecting the same from Vitus 979 frames, but apparently I was wrong.

For reference, souplesse / planing is about the pedal stroke, where the frame, really the top tube, stores energy and releases energy again.
Jan Heine even claims that frames with the right kind of flex will help you ride longer and faster. Myself I am not convinced of faster, but I do very much enjoy the feel. It might be, faster is about uphill ;)
https://www.renehersecycles.com/the-...cs-of-planing/

Currently I only have classic steel frames in my stable. A metric 531 Liberia has a nice feel of souplesse. My Mercier straight-gauge doesn't feel lively or springy and has no souplesse. My camping bikes, most probably straight-gauge (Peugeot 1978, Motobecane 1956), do have a lot of souplesse.
I am a bit confused to simply conclude that straight-gauge in general has no souplesse. Can someone set me straight ;)

And does oversized double-butted steel, like Reynolds 753, have souplesse? And is it true that Vitus and Alan aluminium lugged frames have souplesse?
And modern aluminium and carbon bikes, they don't? Do they feel like pushing against a brick wall?
And if I enjoy a supple frame so much, should I try a classic titanium Merlin then?
Can I simply state that a Vitus 971 probably has more souplesse then a Vitus 172? Or is that a wrong way to thing about it?

And then years ago I read about the Dutch bikes from Zieleman, the seat tube is a bit more backwards with a lower angle. This makes them feel like "they want to eat asphalt", which seems an apt way to describe souplesse.

For the record, it seems many people call frames light (or heavy), or smooth (filtering road noise), or flexy or whippy (in the back) or springy or whatever, but in this topic I am mostly interested in opinions on souplesse.
When people describe a bike as springy, does that also mean it has souplesse?
Anyway, many questions, much confusion here :) about a topic that isn't talked about much directly, is sometimes hard to describe, and might feel very subjective.

The Herse article is sort of fascinating. Would souplesse entail an entire bike flexing with each stroke...such as honking up a hill. Is it synonymous with flexing (bottom bracket moving the frame right and left) with each stroke?

Ah, yes, flexing can be anywhere :)
They mention the right kind of flex. That must mean where souplesse is stored, vertical tension on the rear part of the top tube.
I wonder if sanding a bit of metal off the top tube in the right places would make a bike feel rather different in this regard.

After riding nothing but double butted steel for ever, I no longer believe that late 80s - 90s aluminium racing frames cannot give as much as they receive. This, after putting a bunch of miles on ‘86 and ‘92 Cannondale race bikes. With respect to oversized double butted steel, my 2011 Richard Sachs has a ride described by any lovely sounding French and Italian word you can think of depending on how I choose to ride on any particular day.

Cannondale was often more advanced than other brands when it came to aluminum but that was probably a big part of their popularity. In 99 or 2000 I got to take 4 different Ultegra equipped bikes out for a 30ish mile test ride, one of each material and just had to use my wheels on each. The trek 2300 was the aluminum one, there were a couple of corners leaving the city into the country that the bike chattered over more than the other three that made it very sketchy. Felt unsafe on hard cornering. Lively on climbs but rough on irregular pavement and very teeth rattling, didn't feel safe enough to finish the full test ride, Cannondale at that time was a significantly more enjoyable ride, it wasn't what the shop sold so I wasn't buying one. Modern aluminum tends towards a lot nicer and livelier unless its a cheapie, but old Cannondales can be quite nice, other aluminum classics can be hit or miss.
Of the four, the Litespeed classic was an amazing feeling bike, just the right amount of give when climbing, absorbed all the rough and really could ride all day. It probably embodied this idea of planing, since you could feel the frame move but it never felt sluggish, it just added to the lively feel. The question for me is how much do the wheels add or detract from this flex, too stiff a frame and the wheels will move more and you can feel them rub against the brakes.

This “academic” tubing discussion is to my view, near useless. Riders have different masses and riding styles and frequently different loading of the axles, frames have different geometries AND differing quality of construction.
‘my view is you have to ride and evaluate. Hopefully with an awareness of what you have experienced and from that assumptions of what you want.

that written, the ONLY bike that I might have felt rebounded and provided more than what was delivered was a Teledyne Titan, and that was in a narrow range of effort and cadence. I attributed that to the spring co-efficient of the material. The frame was 74 degrees parallel and a 54 cm top tube. Don’t brake too hard as the wheelbase would shorten 15-20 mm. Was fun, but sold it off for a tidy profit in 1979.

Not to derail, but I thought souplesse was the smoothness and fluidity of ones pedal stroke.

Yes, that is souplesse in the pedal stroke, in the cadans.
Souplesse can be in the frame as well.
Both are about keeping the dead moment in pedaling as short as possible. Especially uphill, a longer or stronger dead moment can pull you more backwards. Keeping the moment short, or have your frame flex back some power, will make it easier to pick the pedaling back up.

This always comes across like trying to sell a bottled moment of zen. A SWAG study of different frames rigged with sensors and dohickies ridden by a wide variety of different riders of different weight and amperages might be used to draw a present a graphic representation of a proposed "sweet spot". I'd guess "Big Bike" has this technology, and it's proprietary.

Yes, I love the sentiment that folks like Jan Heine are putting into all of this but I do have to wonder, sometimes out loud...

‘then there are racers who overcame this, the Sprinter Sean Kelly comes to mind.

I think he's got enough personal results to show his program works... For him. As does his business model. Micheal Jordan sold a lot of sneakers, and I'm sure a some of those kids went pro, but it wasn't the sneakers....

The stepping down of a short section of the down tube to accommodate the shifter band might have had something to do with the rebound, too.

I've been wondering about this claim lately. Results of recent studies have shown that elite/pro bike racers apply force in a shorter section of the pedaling circle than amateurs and non-racers.

Could be that pedaling at higher watts works best with a shorter, harder effort followed by a longer unloaded recovery period/dead moment. The rest of us may enjoy pedaling smoothly throughout as much of the pedaling circle as possible, and that is probably pretty efficient at modest power output levels, but pros are faster.

Not according to Mars Blackmon. :D

My philosophy in life is more soup, not less.

I do like @bark_eater "bottle of zen" sentiment.

the blind test of steel frames from different tubing has been done and documented, experienced riders. Results = riders could not pick tubesets.

However, the effect achieved for each riders' preference is what I call grail. As much as the name on the frameset.

My experience is primarily with Reynolds, Columbus, some Ishiwata.
@DanseMacabre - can't comment on Vitus, but the 'planing' effect I have observed is mostly on vintage frames with longish chainstays (42-44cm), and I refrain from calling them touring frames. Merckx in SLX a cm or 2 above my 'perfect' size had that feeling. Same with AD Vent Noit (531), a tiny large. My Ishi022 bikes nice but did not plane; would liked to have ridden 019 in a 'non-racing geometry frame'. I have also ridden 'whippy' bikes, that went beyond souplesse.

I ride 60cm frames, weigh 190 (86kilo) - I think I cannot speak for characteristics of smaller framed bikes or lighter riders.

what a shortsighted engineering decision that was.
If they had looked around, running the shift cables Under the bottom bracket and tooling up an oversized band clamp for the shifters could have been within reach.
Also could be said, a seatpost clamp collar would have curtailed warranty claims too.
for as unconventional as that frame was for its time, it was conventional.
would have been a good platform to use straight leg forks, the bulk of the flex on the fork was above the rake radius, the radius appeared to work harden the material.

I originally read this thread title as 'soup, please'. Sounded good.

Souplesse. 1000% above my pay grade. I will hop on a bike and hopefully get a 'hey this rides nice!' in my head, rather than a 'hey, I don't really like this'. I know wheels make a big difference. I recently had this experience w/ my Clang find Trek 600 and it was fabulous.

In no way to be construed as detrimental to the original question asked by the OP, I find that the more I pay attention to the fine details and expect to see them show up, the more disappointment that can arrive when I don't find them in the exact way I wanted them to.

The stone cold professional that can detect that 1% and is enthralled with what nobody else can sense, or the hapless happy-go-lucky amateur that can somehow derive immense satisfaction from the silliest piece of junk? I admire the one, and relate to the other. Which is which, is a secret:D I wish I could flip a switch between the two of them when I want to!

Thank you, that is most interesting.
So maybe what feels like souplesse might be something else, more flexible in the rear triangle, either vertical (springy) or lateral (whippy). Or maybe it is souplesse as the function was described., but not at the toptube but in that rear triangle ;)

I am here to learn.
And sometimes theory "dictates" a certain systemic way of thinking, but in practice it might all be different.

By the way, I often wondered, what if chainstays would be more wide and lateral stiff, but vertically more compliant? I recall a recent discussion about it, and the bikes like that, that do exists, weren't great rides.

In trying to find an engineering term that might match Heine's description of "planing" (which I think was a poor choice of terms, at least from a marine perspective), the closest thing I could fathom was constructive resonance. In design we went to great lengths to avoid that since it can give results like the disintegration of the Tacoma Narrows Bridge but musical instruments use it to great advantage. However, the forces that "excite" the structure, in this case the bicycle, have frequency and amplitude which I think are going to vary from rider to rider based on how strong they are and their preferred cadence. That would imply that a bike that works well for one rider may not please another since while it may achieve a constructive resonance for one it may just feel dead to another.

Yes, that is interesting as well. I remember on this forum someone mentioning a bike that had a different resonnace to his cadence, which made it all wrong for him.

reference ibis Bowtie

Very frustratingly I can't now find the video, but it was a steel bike set up with the rear wheel off the ground. They loaded the pedal until the frame flexed considerably, and then when released the energy from the frame went into the drivetrain and the rear wheel starting rolling.

When I'm not on my desktop I'll try to find it.

:thumb:

But again, many variables in achieving the mythical 'constructive resonance' of a frame contributing to a 'better' ride. Tire and pressure are a huge influence, ie, fat tire/low pressure kills frame characteristics. Rider characteristics, cadence, smooth spin each make a difference.

Sometimes when on a long steady straight paved trail - I'm feeling in the groove, on tubular 25mms @105psi - everything in sync, the lugged steel bike in 'harmony' with rider for efficient performance - then I make a turn and realize - that slight tailwind might have contributed more than constructive resonance planing. :o :D.