82

The simplest answer to your question is that 1) speeds have increased; but 2) speeds would have increased even more except Tour organizers have been consciously making the Tour harder in order to increase the drama, suspense, and entertainment value of the race. That makes comparisons of overall winner's speed quite complex when combined with normal ...


57

What really struck me though was that the average speeds really haven't changed much The chart ranges from about 25km/h to over 40km/h, and that is a big change. As others have mentioned, increasing your average speed requires a non-linear increase in power applied to the pedals. In other words, to increase average speed from 25km/h to 26km/h is easier ...


45

There are a few "pseudo-facts" I think might be at play in this graphic: You mentioned 10% of increase, say from 35km/h to 40km/h average speed. That is a VERY significant increase. Anyone well trained can sustain 35km/h average for some time even in a mountain bike, but FORTY km/h is MUCH HARDER to sustain, and that's because aerodynamic drag is ...


21

I am not a bike expert, but a computer programmer. The problem with this question is that there is no control to compare it to. Each year the TDF changes. They visit different parts of Europe, yes it is not 100% in France. This means you can't compare times between years. Weather (not climate) is a concern. The temperature, wind and humidity will impact ...


19

The Tour de France is primarily an endurance event, where team strategy is more important than outright speed. In addition there are UCI rules for racing bicycles. This includes a 6.8kg weight restriction that has been in place since 2000. If you want to compare outright speeds it would be more interesting to look at how the average speed of the time ...


15

Standard Pawl and Ratchet Design This design is by far the most common on bicycle freehubs, and as such the least expensive to employ. Mechanism In it's simplest form, this design consists of a surface that is toothed and a pawl (which is a lever that engages the toothed surface and only allows movement in one direction). In a bicycle this design is ...


13

Last year I plotted average speed versus race distance and there's an incredibly accurate inverse relationship. http:///www.32sixteen.com/2011/07/25/correlation-does-not-equal-causality/ But to add to my chart and flesh out the reason I think it hasn't increased so greatly. The Tour is a stage race. The average speed we have presented is the average speed ...


12

The answer is "both, depending." The majority of current bicycle cyclometers use a reed switch and timer, and measure the time between successive triggerings of the switch as a magnet passes by. An advantage of this method is its simplicity and low cost, though if the magnet is ill-positioned or if the rotational speed of the wheel is too high, the reed ...


12

The raw pedal force or torque data are difficult to work with but you can extract some information from them. First, note that Stages mounts the strain gages (or gauges) permanently to the crank, so the crank length is constant and they know what it is; that means that there is a one-to-one relationship between the kgf and torque columns. In this case, it ...


12

Boardman used what is known as the "Superman" position, as shown in this image. This position has been deemed to be against the rules by the UCI. Compare it to the position that Wiggins had on the bike, shown here. His arms are not as outstretched, and therefore it is not as aerodynamic. The superman position was first used in the hour record attempt by ...


11

I'd say the biggest change is the shift from coil and oil shocks to air springs. Even at the cheaper end of the market most bikes designed to go uphill will be using air shock suspension. Air suspension is lighter but in the past has performed less well and been more expensive. Over the years price has fallen and performance has improved. The other big ...


10

American Classic Cam Plate Design The full name is "Six Pawl Cam Actuated Engagement System." This design is one of the more complicated ones, but according to American Classic provides a stronger freehub with relatively low resistance and causes all 6 double tooth pawls to engage simultaneously with high precision. Mechanism There are several parts to ...


10

Radial bicycle tires are very rare. The reason is that the lateral stiffness is much lower than for cross-ply tires. Imagine that you press the sidewall of a tire by your thumb. With a cross-ply casing the cords on which you apply pressure are anchored to the bead wires over a distance of about twice the tire width and the whole section shares resistance to ...


9

The Rockshox at Paris Roubaix were a Greg LeMond thing. Whatever Greg competed in a few 'out there' cycling innovations came along with him. Remember those tri-bars that gave him the aero tuck position to beat Laurent Fignon in the Tour de France? On that event he also had his own road bars that had an extra position, where the drop handlebar end plugs would ...


7

This question makes a category mistake, I reckon. In that the Tour de France is not a competition done to finish an enormous amounts of kilometers as fast as possible -- as would be the case with a marathon for runners; where they athletes do indeed go faster and faster. The only aim the winner of the Tour has, is to be faster than the number two in the GC. ...


7

To me (and for others, I think) the greatest paradigm shift (that should become widespread in the near future, my opinion) is the inertial-controlled compression-lockout valve (Fox Terralogic, Specialized BRAIN). These work as automatic lockouts, which make the bike stable if the rider pushes it down (like pedalling hard on a smoot uphill, or sprinting on ...


7

Star Ratchet and variations This design in it's simplest form is used by DT Swiss. This design incorporates easily replaceable ratchet plates that offer the added benefit of every engagement point transferring torque. A more complicated variation is what is used in Chris King hubs. Mechanism - DT Swiss 1. end piece 2. bearing 3. thread ring 4. axle 5. ...


6

Think of a cyclocomputer as a hardwired combination of a calculator, a quartz-clock, and a dedicated CPU working with a buffer. EDIT TO A MORE PLAUSIBLE ALGORITHM: Each time the magnet closes the reed-switch, a request is sent to the clock to capture a time-stamp, a time-stamped event is sent to a buffer, and the wheel circumference is added to the current ...


6

There have been designs, but cyclists tend to be picky about increases in weight or losses in efficiency. Bicycles do not have the problems of large spinning masses or rough clutching at low speed, and we seem to do OK with discrete steps in the gear ratio.


5

As others have pointed out, The TdF is an endurance race. It's not about all out speed. For a better idea of how bike technology has increased, check out the list of Hour record holders. This is done on an indoor velodrome, with no other people on the track to the person can't draft. The premise is to ride as far as you can in a single hour. The ...


5

Two things that must be considered when looking at the average speeds of the Tour de France are strategy and racing dynamics before you look at the numbers. The main strategy objective for any of the teams in the Tour is to go only as fast as you must to achieve a given objective while doing the least amount of work possible. If teams could win the tour ...


5

I think you could take this technique pretty far, but probably not all the way (at least usefully). I see a lot of use for the first part of your plan: taking multiple pictures and reconstructing a 3D model. If you try this for multiple postures I think it should be possible to determine an optimal position for you on your bike based on just looking at the ...


5

Has anyone experimented with using consumer 3D software to do CFD-like aerodynamics simulations? - Yes Could there be any worthwhile insights gained from this? Yes However, you should not view work like this as an alternative to using a powermeter or windtunnel testing. View it as a tool that can be used as an extension of sound methodical testing, to test ...


5

While not disagreeing with the first answer above I think there are a few more complexities that haven't been addressed. Changes in bike technology are not linear but rather generational. Component improvements don't happen each year but rather every 3-4 years. Aside from pro and sponsored riders most riders would not see any value in replacing a bike for ...


5

The NuVinci® N360 is a continuous variable transmission that is roller based. It is marketed and used mainly on hybrid and low maintenance city bikes. They must have had some market success as they have been around since 2006. I recall seeing them at Interbike around that time. More info in the internal structure


5

Sprag Clutch The sprag clutch has existed in industrial applications for some time: being used in motorcycles, helicopters, airplanes, automotive transmissions, and others. As far as I know, Onyx is the only company to bring it to bicycle hubs. Sprag clutches offer low rolling resistance and virtually instantaneous engagement. They are also reliable and ...


5

From the internet: "Half Link BMX chains were designed to help dial in the chain length on frames with short dropouts and small gearing, making sure your rear wheel is exactly where you want it. Dan's Comp offers a wide variety of half-link BMX chains for both race and freestyle." Basically, you can break your chain at smaller increments to get a more ...


4

Besides all technical aspects race speed is also a question of racing strategy. As long as there is no escape group no team might feel responsible for making pace, so the peleton might ride "slowly". Once there's an escape group the peleton might decide to keep some distance so they can catch up later, while the escapers might safe energy for a final sprint ...


4

I have ridden road bikes of all sorts over many years in road races, time trials and over many miles of general riding and club runs. For most of those years the bikes had forks made of Reynolds or Colombus steels but with a reasonable rake. In later years the rake decreased and in some cases disappeared altogether with the result that the front of the bikes ...


4

Suntour makes a significantly different designed road suspension fork I found on Wired Magazine while Googling. Here is the Suntour product page


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