Timmi

Just curious as to what you used as a radius, so I can compare to my wheels and tires?

Hey, btw, I started restoring it... making a singlespeed for the road out of it. Put a brand new Campagnolo Veloce on as a front brake (had to drill the semi-sloping Columbus fork crown for that). I can't believe how WEAK the spring is in those brakes! Doesn't Campagnolo have experience and make quality? With new cables and teflon liners, no bolts too tight either, they go back out really slowwwww when you release the lever.
Found some nice Continental tires in my storage area... a 23C for the rear and a 19C (160psi!) for the front. I really had to put all my weight on the floor pump in the end as it was approaching 160. What is nice about old tires you had in storage, is the rubber has had a chance to dry out and grips better in the turns. That's a fact, even with the new compounds.

I'm wondering if the 4mm extra tire dia in the back will change the angle much... I'll check with my inclinometer, because you can't predict mathematically... different tires, different diameters, different pressures... you can't predict exactly how they crush will play out under my 210 lbs. I suspect that this will just have to be measured in the field... once that wheel is built.

I have clinchers I'm putting on (still need to build the rear wheel though - broke my bench vise trying to get the freewheel off a wheel so I can recover the nice Wolber Alpine rim that's on it to build the wheel with it). I've had that Wolber Alpine rim for over 2 decades now, and it just won't die! It's really been through a lot!

But I'll pump up the original track wheels and tubulars just to measure what the original radius was that this bike was designed in mind with. It always varies a bit, from wheel to wheel, tire to tire... so it's nice to have the original wheels. OK I know... I'm off on a tangent (pardon the pun). Couldn't help it - I'm enthused about building it up again and getting rid of my back-basher (if you can believe something is harder on the back than this bike - well indeed there is: a 1984 Canadian Olympic Team aluminum Canondale road bike (an actual spare from the team - has no-labels on it as sponsorship wasn't allowed in the games back then).

So, until I find my Cambio Rino I'll just ride this... and my recumbent... and my mountainbike (hey, winter is coming, so although the child seat is coming off, the winter spike tires are going on soon).

Road Fan

I used 330mm as the radius.

Road Fan

without considering loading, your tire difference steepens the HT by about a quarter of a degree.

Timmi

Original NISI rims, with top of the line Clement track tires, outside radius is 340. Knock off a couple of millimetres for loading - ah heck, lets make it -3= 337mm radius.

Road Fan

Ok, if I take your HTA as 74.75 considering the 0.25 degree frame tilt, your radius as 337 mm, then the trail is 52.0 degrees. Many commercial higher-end bikes today (most?) are pretty close to 60 mm. I think Nessism or Thylacine was suggesting a design target around that point as well?

I'd try measuring the fork rake with a different method, just to test. I'd say your number is plausible, but I'm not sure I understand your method. Did you get a string to be parallel to the steering axis? I'm not sure I see that you did, from your description. If you did, how did you sight it to know it's parallel?

This IS the hardest measurement.

Timmi

The bike was measured with the wheels off actually.
I re-mearured everything today. Wheels on this time. But my inclinometer is [+/-] 1 degree, not the most precise device, but it's better than nothing (digital ones were too expensive for the little use they'd get) - so any fractions are guesstimates. Head tube angle appears to be actually a fraction over 76 degrees, seat tube angle a fraction over 77 degrees. Sorry for the mistake.

Co-planar. All 3 string segments were co-planar. You can sight that out quite well. Why don't you give it some thought as to how you'd do that accurately? Hint: the string goes through the front dropouts, and from each dropout, drapes over the stem/extention.

BTW, the handling on this track bike appears less than ideal. It appears not to be conform to conventionally accepted geometry standards. I merely answered a question here, but there is nothing mission critical about this. So according to your expertise we have 2 inches of trail... I think that with a little more trail, the bike would handle much better (on the road). But then again this is a real track bike, not some commercial knockoff destined for bike messengers riding on pavement with their singlespeeds. And on Montreal's velodrome, this thing was agile as hell. Accelerations with the stiff tubing was better than anything else I'd ever tried. We had 49degree banks, and I used to plunge down from their summit, be able to pass someone on the inside at the bottom at full speed, which made for a very sharp turn, on an incline (and leaning the wrong way to make the turn), and this bike always handled beautifully. Not to say that I didn't get a scare sometimes while doing that - but it never let me down in even the toughest of situations.

Road Fan

Frame angles with wheels off or on shouldn't matter. The extra 1/4 degree comes from your stated differential radius of 4 mm, front smaller than rear, and the claimed (average) wheelbase 38 inches.

I notice that now your measurements are different from before. This is not bad or unusual, I just note it. But it does indicate why one often should repeat a measurement process a number of times, at least three, and report the average value of each measurement.

Regarding your strings, if you have an explicit method for making sure the strings are parallel to the head tube, please explain it. I'm not going to guess using hints. The problem I see is sensing or seeing the actual steer axis and extending it long enough (and accurately) that you can easily see if the strings are parallel to it.

The only accurate method I know for fork rake is to remove the fork, fixture it so the steer tube is parallel to a reference plane, and perform precise measurements from there with machinists' tools. The only accurate method I know for head tube is to read teh angle of the head tube with a digital angle meter with the head tube badge removed, or made irrelevent to the measurement, with the frame in a known orientation. If you can't do these things, I think my on-bike method done with digital tools is reasonably good. I don't get how yours shows the direction of the steer axis.

FROryder

I raced many a crit in Montreal during the mid eighties on both a Marinoni and a Gios Torino. The Gios was hands down a better handling bike than the Marinoni in any situation including blowing past cars and motorcycles down Camilien-Houde parkway at 100kph. Get a Gios and be done with it.
Cheers

Timmi

ROTFL! YES! Glad someone finally understands!!!

And about the GIOS, that's exactly what I was starting to think too. I think I may have seen you back in the day... there weren't many of those GIOS bikes around, and I remember noticing one.

I don't really "need" one... just sick of my canondale...
once I got the frame geometry, I was intending on either buying if I got a great deal, or just outright making it myself out of carbon fiber.

For the moment, I'm embarking on making some carbon fiber recumbents... when I have some free time, if I haven't found a Cambio Rino or GIOS at a great price, I'll just make it.

The Marinoni is whas conform to conventional racing geometry as outlined in Cinelli's 1972 Cycling bible, and 90% of today's racing bikes on the market today are identical to that. NOTHING has changed, although our roads got better, allowing for more aggressive geometry, as outlined by the man himself who laid out those geometry guidelines back in '72.

Thank you for your support! Glad to hear from someone else who saw the light. ;-)

Where are you now? Still in Montreal?

PS: I just reassembled my track bike, but made it road-ready this time, as I mentioned... there IS something nice about an old lugged handmade frame that is sort of irresistible... I ordered a singlespeed wheelset for it... not sure what I should do with it now. Decisions decisions...

FROryder

Still in Montreal, but the Gios is in Bulgaria. Currently ride a Serotta legendTi.
Cheers

nenad

This is a post pasted from another thread, I am putting it here as it seems very relevant to the discussion.

I actually got a very good read so far and I think OP has some very valid points plz read below.

I recently bought a Gios Compact from 1990 decked out with a complete C Record. Although heavier than my first bike (Basso alu/carbon with Record) it has quickly become my main ride. What I have discovered is that due to steeper seat tube angle my whole position has shifted more forward and over the BB allowing me to step on pedals with more force. This I expected. What I was surprised about is that this bike is great for going uphill as well especially when out of the saddle (because of shorter wheelbase? Somehow, I am better positioned over the bike when out of saddle on this bike). As far as flex is concerned, when you do a static flex test (off the bike, pushing down the pedal) Gios flexes more than Basso but proves to be a snappier ride; it responds better when pushing on pedals out of saddle. I don't know how to define the feeling except to state that, somehow, Gios has more character than Basso. While being a fine ride, Basso is neither here nor there, for example, I couldn't define it as either bike for flats or hills (think of expression "jack of all trades, master of none").

The only question that remains is, is this all in my head? I am well aware of "new bike fever" but after 1000 km on Gios, I am truly wandering, can it be THAT better than a much newer Basso...

To remain fair to the discussion I should also say that both bikes are fine handlers (Gios will steer more quickly and is harder to ride no hands) and I don't necessarily see difference in average speed of one bike over the other (it's the engine, not the bike), Gios just feels more right...by a considerable margin.

The geometry of the two:

Gios:
Tubing - Oria Ranf (spiral (rifle) butted)
HTA, STA: 74 deg
TT: 55.5 cm
head tube length: 16 cm
chainstay length: 39.5 cm
fork rake: 45 mm
wheel base: 99 cm

Basso:
Tubing - Easton Ultralite triple butted aluminum front triangle - carbon chain/seatstays
HTA, STA: 73 deg
TT: 56 cm
head tube length: 17.3 cm
chainstay length: 41.5 cm
fork rake: 45 mm
wheel base: 100.5 cm

Height of handlebar and saddle same on both bikes. Both bikes are equiped with Mavic Open Pro rims, on Gios laced 4x 36 holes, on Basso laced 3x 32 holes. FWIW, I am 185 cm tall, weighing 71 kg right now.

Any comments are most welcome.

P.S. If any other measurements are required, request them and I'll do my best to measure correctly.
P.S.1. I second the opinion of previous poster that Gios Compact Pro may well be a frame with the geometry OP is looking for. I say, try to get hold of one to test ride it.
P.S.2. Attached are photos of two bikes discussed.

Timmi

2017 EDIT of an old deleted post...

OK, coming back to this thread in 2017, after a long hiatus.

(sorry guys, and @nenad, I started using a different email address. and no longer saw notifications)

I did learn a lot about frame geometry during this period, and know more now than I did then.

Timmi

I have to wonder what method you used for rider positioning. No matter how tall or how short, unless a human has abnormally longer or shorter femurs or tibias, people fit onto a 72°-74° seat tube angle, in all rider heights. (and the choice within that range is more for intended purpose).

It is amusing to see you say that there was no such thing as a criterium geometry, and then, in the same breath, you state that there was, but it just didn't catch on. A criterium geometry is basically 3 differentiators with regards to a road-racing geometry: 1.a steeper head tube angle, 2.higher bottom bracket, and 3.shorter wheelbase (some models were so short, that the front tire would overlap with one's toes while turning).


The mistakes we often see on bikes, is geometry modified for the wrong reasons:
For example, on the smaller frames, we see a steepening of the seat tube angle, and a setting back of the headtube angle, to keep the top tube from being too long for the frame height while keeping the front wheel from overlapping the feet. The seat tube ends up at an uncomfortable angle, leaning the rider forward, as for in a time-trial bike. The bike is uncomfortable (justified trade-off in a 30minute-1hr time trial, but not hours-long road race or training), and more "stable" (read: slower-turning) bike, than the riders get in the larger frame sizes. The right thing to do, would be to change the wheels for 650 or even the 26" standard in the smallest of sizes. Short riders often complain that the reach is too long - that is no coincidence: look at any bike that is under 52cm, and often, you will see that top tubes start to elongate in relation to the seat tube length, as we go down in frame sizes. I've seen a 43cm with a 50cm top tube (and that was a 650 model).

Timmi

I would be curious to know their respective bottom bracket heights.
Aluminum and steel feel very different. Alu feels a little dead. Steel will flex and spring back, but most often, when it springs back, that energy doesn't move the bike forward because your pedals are past that point to benefit from the return movement. Aluminum isn't so springy - any flex it just absorbs and dissipates - hence the different feel.

Your livelier handling is explained by the steeper head tube angle on the Gios. (Can you re-measure that? I thought a Gios Compact would be a bit steeper than that.)

The 2cm difference in the wheelbase is mostly due to the longer chainstays on the alu Basso. This makes for a better weight distribution, and combined with the 73°HTA, is what makes for a more stable ride. I now own a Turconi (made by Vanni Losa) that was very unstable in the front end. The seat tube is pushed in to make a concave section to accommodate the tire, in what is an extra-short chainstay configuration. I recently moved to 28c tires, and had to remove the dropout stop screws to move the wheel back farther, to have enough clearance for the tires. I immediately felt more stability on the front end. It used to wobble at moderate speed if I let go of the handlebars, and no longer does that. The higher tires might have helped as well, as that would increase trail by a little bit. It is surprisingly resistant in lateral flex: the chainring doesn't budge. I have to suspect the specially-shaped seat tube.

Pushing on the pedal beside the bike is not my preferred way of evaluating flex, because it includes flex from the fork, wheels, and tires, and thus does not reflect the efficiency of the frame. Instead, ride uphill and see by how much your chainring moves from side to side in the confines of the front derailleur (presuming it is straight, and there is no play in your bottom bracket). Try in the same gear, on both bikes, a few times, to compare.
And btw everyone, when you pedal hard, it's the seat tube (held in place by your through the saddle) that is resisting the side-flex, not the downtube as all seem to think.

Here's my ride today, a Turconi made by Vanni Losa:

Andrew R Stewart 

Timmi- 9 years is a long time to learn about geometry, glad you have. However I question your blanket statements, like:


"I have to wonder what method you used for rider positioning. No matter how tall or how short, unless a human has abnormally longer or shorter femurs or tibias, people fit onto a 72°-74° seat tube angle, in all rider heights. (and the choice within that range is more for intended purpose)."


Not all riders find that KOP is the best answer for their needs and most all fitting systems follow this principle. Some riders do have limb lengths that fall at the ends of the bell curve. In fact many riders seeking a custom frame have found that the common geometries don't work well enough, hence the custom choice. (I have a friend who while following KOP has no seat set back at all, her seat tube angle is 74+. She's about 5'1" tall and has about 1/2" leg length difference).


As to crit geometry- I always felt this was more about marketing then function. Sure bike companies (and the advertising dependent media) marketed bikes to the US crit scene at one time and used the term doing so. But merely labeling a geometry does not make the bike a better tool. Time and experience showed that. So was there a crit geo? Sort of, if you accept what those who want to sell you a bike say as the only truth. But this type of discussion isn't trapped in time. What we currwently call touring geometry was once professional racing geo. What was called crit geo is much like match sprint track geo but with gears and brakes.


"Aluminum and steel feel very different. Alu feels a little dead. Steel will flex and spring back, but most often, when it springs back, that energy doesn't move the bike forward because your pedals are past that point to benefit from the return movement. Aluminum isn't so springy - any flex it just absorbs and dissipates - hence the different feel."


Many who prescribe to "planning" would take issue with your claim that a steel frame's flex is not helping power the bike. Planers like to believe that the flex and the rider can have a sweet spot that makes the bike feel more efficient. Not sure I agree but their claims are interesting to think about. For an AL frame to absorb the flex and dissipate it would mean the frame will heat up (as it's gaining energy). It also would mean that the AL frame would not return to it's original shape as the flex was absorbed and not returned back into the bike. I don't see this outside of incidents which are also warranty voiding.


Larger tires result in slowing down a bike's snappiness is a well known method of taming a bike. The greater rotating weight, the greater tire flex collectively mute the willingness to change direction from steering inputs.


Bike handling isn't just angles and trail though. Your comment about having a better weight distribution is correct but I would say it goes to bike handling in general and not just the greater stability side of that bell curve. The hips do a lot of the steering and where that leverage point is (meaning the seat) relative to the tire contact points (front center and rear center are common references to this albeit indirect) influences handling a lot. Some feel that the hand placement WRT the front tire contact patch also is a big factor, I'm still undecided about strong a factor this is. And there are other handling/fit/geometry philosophies. What's interesting is that for all there's both someone who works really well and another who feels like crap.


Pretty much all the serious literature I've read on the subject of what affects frame stiffness suggests the down tube's torsional stiffness is a greater factor to BB sway then the seat tube's bending stiffness. Can you elaborate on your claim that the ST is the greater factor? Andy

unterhausen

there is a minimum angle between torso and legs that makes sense from a performance perspective. So if you want to put someone in a time trial position, then you need to move the saddle forward. Similarly, for an upright position, moving the saddle backwards makes sense.

Timmi

Andrew, I realize that many articles have been written on alternate methods than KOPS. But as a former athlete, and later team trainer for 2 different teams, I have to stick to it's logic, which is anchored in sound biomechanics. Within KOPS, certain riders have different riding styles (which we can argue is less efficient or not), and which will call for deviations on that. But you'll have deviations on no matter what method you use. STA can be changed to fit a rider, no problem, as it doesn't affect steering. (it does affect weight distribution, but ergonomics should come first, as any adjustments to weight distribution can be fine-tuned with the chainstay length.

YES, there WERE criterium bikes. But they were not the ones you think. They weren't necessarily the (insert brand name) labelled "criterium" any more than the department store bike labelled "racing bike" actually was one. My Rino was a criterium geometry as I have described, but it was labeled... I'll come back and tell you if I remember (or can read it off of an old photograph when I find it) - maybe Corsa, or Competition, something like that. And I have had friends who had bikes with a Crit geometry too. Wish I could remember the makers. Anyways, just because you did not experience or were not exposed to something, doesn't make it impossible to have existed.

You choose your words carefully: "feel more efficient" isn't the same as "being more efficient". If proven wrong, you can argue that you didn't commit, but was just in the mood for arguing. ;p I've thought it through, and I don't think any flex is more efficient. Flex, done the right way, becomes part of the suspension, as slight as it is on a bike. Done the wrong way, and you have cable tugs that are sufficient to switch gears with your rear derailleur when going uphill, as I had experienced on a Columbus "Special" ride (beats me if in this case "Special" referred to SL or SP - probably a mix of the two, as it was a 60cm, size at which they start to use SP in SL-class frames).

Let me tell you about downtube flex, and most modern bike designs. Do you remember Bicycling Magazine? And their spinoff, I believe it was called Bicycling Tech, or something like that. Their way of becoming famous (which didn't prevent it from being a flop because of too little readership), was them building the "Tarantula". A large, complicated frame jig, that was designed to test the flex of different bicycles. It anchored the bike at the dropouts and the headtube (perhaps also at the seatpost? - I can't visually recall that), and they applied a force to the crankarms, externally. It also makes the presumption that you are pulling with your arms, to push on the pedals.
And it was from this that they concluded the flex was coming from the downtube. And everyone believed them. No one ever questioned their methodology, whether they were doing it right.
I can go up hills, no-hands. The steepest ones I have to rest my hands on the bars, and shift my weight forward, otherwise the front wheel goes up off the ground, but you get my point. When you are able to properly pedal, exerting force 360°, it's your saddle, anchored between buttocks (from gravity) and against your inner thigh, that is the resisting other end of the lever. The downtube has a role of stabilizing the bike, preventing it from twisting at speed, and assisting those using their arms too much in order to compensate bad pedaling style. You can watch "the cycling network" videos on youtube where they teach you how to do it wrong. But there is so much length to be twisted there, under torsion, that a cast bottom bracket with an OS seat tube (or with a longer butted section at the base), can better to overcome the BB sway. And BTW, Colnago has got it wrong. Downtube needs torsional rigidity. Their crimped Gilco tubing, co-designed by Ferrari who know nothing about bikes, only results in a ride that transmits more vibrations to the rider, with a downtube that has worse torsional rigidity than a round shape.
And there you have it. I don't want to get into deep discussions publicly, on how it should have been done, because there are several elements about bike design that I wish to keep a trade secret, once I start building in CF. So I'll just leave it at that.

"Larger tires result in slowing down a bike's snappiness is a well known method of taming a bike." THAT, if you re-read yourself and stop to think for a moment, is silly, even by your own admission. Come-on! Surely you don't actually believe that. It's merely a symptom of cheaper tires. But I never said I put cheaper tires on my bike! They are Continentals. And the weight difference between 25c and 28c, within that brand for the same model, can be less than what you will see between differing brands for the same tire size. My 28c Contis weigh about the same as the 24Cs I have on my other bike. I stand by my statement, that it's the slight increase in trail, combined with better weight distribution, that solved the problem of the front wobble at moderate speed. BTW, I learned something from skateboarding to which few in the cycling industry are privileged: going downhill on a skateboard, speed wobbles become an extreme condition, which are easily resolved by shifting your weight onto the front truck. 100+km/h is all of a sudden no longer a problem. Moving the back wheel out (or shortening the top tube), are ways of changing weight distribution. Of course there are trade-offs, affecting handling, bike for for some riders, and braking.

Timmi

Does anyone here have back-issues of the leaflet called BicyclingTech or BikeTech (or whatever it was called, published by Bicycling Magazine)?

If you could upload a picture of their "Tarantula" frame-flex testing jig, with a bike frame in it, that would be very much appreciated.

Timmi

I hope you're still around. I only got back to this thread after I returned to an old email address I hadn't used in years, and saw the notification.

What was the Seat Tube Length? (C-T)

And if we could know either the BB drop, or height, that would be great too.

I always wanted a Gios Compact. Just could never afford one, and now, can't find one at a good price.

Andrew R Stewart 

I well remember the Tarantula test rig and the Finite Stress Analysis effort done by Bicycling. Bike Tech was an interesting read until it became more of a marketing rag for it's sponsors. IIRC the Tarantula had some bike holding issues, as in not allowing complete freedom of motion due from the pedal pressure. There was a review of it some years later in one of the mags describing in better detail the short comings.


But all this focus of stiffness is, IMO, miss guided and not really wanted by the sporting rider masses. Just look at the very fast acceptance of the road bikes with some sort of shock damping designs (Specialized Roubaix and the Trek Domane come to mind), the call for deeper padding on (now) oversized and stiff bars and the search for lower pressure tires.


So I never gave the stiffness tests much importance in how I looked at how to design my frames. Instead I look at how a bike's design can benefit the rider over the long term, not in the imaginary sprint we dream of winning.


Timmi- I suspect we are closer in mind as to design and fit then it looks like in this thread. I do raise my comments because I saw some overly broad claims and a bit of word play that IME isn't what is really going on. I do find it interesting that you're aiming toward the goal of frame building. I hope you both make it happen and keep us in that loop. I also will find it interesting to see how your views evolve over time and hands on experience in building for clients as well as now having to be part of the greater market place.


While this forum is interesting I find that over on Velocipede Salon the business and personal motivation info is better. Also there are more real builders who chime in, including more then a few carbon builders. Have you checked it out? Andy

Timmi

Many people, including builders, have gotten the term "stiffness" completely confused.

You want to increase stiffness in the direction where your pedaling flexes the frame, which results in small efficiency losses (for the mechanics of which I have explained). But not increase it in the vertical plane: there, you want to exploit/allow any possibility of more "compliance" as they like to call it.

The Trek design you mention, with the split in the seat tube, maintains the lateral stiffness thereof, while allowing flex on the vertical plane, so as to absorb some of those road shocks. I haven't tried it, but in theory, if they have twist under control, that design would have no to very little effect on efficiency, and may even enhance it because the rider is getting less beaten up. Smart folks over at Trek.
As for Specialized, it's not a company I will ever buy products from again. For their morals (aggressively flexing their monetary muscle to litigate smaller competitors into the poorhouse), and for too many failed products of theirs that I have had over the years, to (most likely intentional because no one is that stupid) integrated designed flaws/obsolescence (limiting the lifespan of the product before you have to buy replacement parts/product from them). I just don't trust the company: I see the image they project just as well as anyone else does, but their actions and products have contradicted that in my experiences.

Cases in point, here are some examples of builders completely confused with "stiffness" and other design decisions:
Daccordi (and others) On some of their fancier models (Griffe), vertical plates behind the head tube lugs (inside the lug elbows), to stiffen it there... on the vertical plane. That is NOT what riders mean, when they say they want stiffer! All that does, is make life more miserable for the rider, while adding zero performance/efficiency benefits. I even saw a model with a larger, full plate brazed in behind there, to make the torture even more complete.
Colnago with dual downtubes: You need added lateral stiffness on the seat tube. The downtube needs torsional rigidity. An obvious fail there.
Moser (and others) How about those time-trial bikes, with a seat tube curved back and over the rear wheel, to shorten the wheelbase. That only makes the bike twitchier and follow a more erratic course, actually increasing the distance you are traveled, versus a standard racing bike. Use that idea on a criterium bike if you must, not for time-trials.
Aero tubing: well, wasn't that just one of the dumbest ideas ever. Poor lateral rigidity in the seat tube, poor torsional rigidity in the downtube, more transmission of those vertical road vibrations. Dumbest idea ever.
Ferari (Colnago) crimped tubing: Like aero tubing, the torsional rigidity of the downtube is compromised, while the shape transmits vibrations very well, riders report. And the aerodynamics, well, they head in the opposite direction of where the aero tubing is supposed to take you. Gilco tubing might be good inside a car chassis where everything is joined together in pyramidal structures, but it doesn't transpose itself well into a 2D structure.
Colnago: or how about the bikes that eliminate the seat tube altogether? I suspect the Tarantula is at fault here, because it was affixed at the dropouts and head tube. It did not take into account the essential lever that the seat tube is, on a bike.
In fact, most bikes today, are designed with oversized downtubes, because that is the way the Tarantula tested frame stiffness, and this stuck in the minds of many, becoming the newly accepted "truth" : using the wheels and handlebars as anchors, and not the rider (where the seatpost, with the saddle, is anchored against the rider, between the legs, and forms the perfect anchoring point for the lever that the seat tube is, when pedaling.
And let's not forget a final piece of torture equipment for the cyclist, which adds no performance benefit: the straight fork blades. While these are less costly to mass-produce (because you are eliminating the curvature, and need to have them all evenly curved), they somehow made it onto mainstream bikes as a modern "upgrade". No more shock dampening by the curve at the bottom. Now all vibrations are transmitted to the bottom headset bearing, where it's life may be shortened, vibrating the frame, and then, following along the steerer's path, into your palms.

Yet, racers have won races on such bikes! This prives only one thing: that despite the design, it's the rider who makes the win, not the bike. They won despite the insane design flaws their sponsorship made them ride on.

To the general readership here: Never be afraid to question what is being done. Try to understand the why, and then ask yourself: does it work? Sometimes there is a "why", but it fails in execution.

Here are some pictures of the nonsense I was referring to:






No, I am not experienced with Velocipede Forum. Most forums activities have been gradually migrating to facebook groups over the past decade. I try to keep my memberships per topic/task to a minimum (attempting to have a life - failing at that already), and just chose the largest or what seemed the most pertinent one. Maybe I should check it out, as I'd like to be in touch with more builders.

Andrew R Stewart 

Timmi- You forgot the Slingshot bikes. Andy (who does understand the difference between stiffness and strength but not enough to copy and paste from a Goggle image page)

Timmi

Darn! And I was really hoping you could be the one to help me insert an image, rather than the current method which only links to an image that is elsewhere on the web. It makes uploading one's own images tedious, as they have to be placed elsewhere first. You have an icon that looks like a picture with a mountain on it, to insert a link to an image already on the web.

I can't be putting every abomination up that is out there.

You did, by the way, word your reply, in a manner where it did leave open to interpretation that you were not making the distinction between the different planes in which flex vs. rigidity can be good or bad, and just brushing it off overall. Now that you have clarified that, we understand you better. ;p

You were talking about this, weren't you?



This thread is turning into the house of bike horrors.

JohnDThompson 

I think Andy was referring to these bikes:

Andrew R Stewart 

Yes, John is correct. Andy