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Comment by pgreenwood | Hacker News Reader

If this drivetrain achieves its claims I will be very impressed. Shaft drive designs have been around for as long as chain drives; and they have never been as efficient. Much is lost in the torsion of the shaft. A 2% increase in efficiency is an absolutely massive gain. The cycling industry is littered with flashy looking innovations that don't live up to the hype. The basic design of a diamond frame and chain drive has not been improved upon for over 100 years.

But every now and then there are innovations that actually take hold. For example, the slant parallelogram dérailleur, hydraulic disk brakes, suspension (for mountain bikes), and recently single narrow-wide front chain rings. We shall see how well this drivetrain goes.

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> The basic design of a diamond frame and chain drive has not been improved upon for over 100 years.

Except we have in the form of recumbent bicycles which have a huge aerodynamic advantage but they were banned in the 30s by making rules to enforce the frame dimensions.

Recumbent bikes hold the world land speed record on a bicycle if the definition of a bicycle is "2 wheeled muscle powered vehicle". For example the flying 200m speed record is 133km/h (flying start, flat ground, 1.66m/s tail wind max). 1h distance record is 90km while for normal bikes it is 55km etc.

Basically rules stifle a lot of innovation in the cycling world. Most pro bikes are too light to race legally so they have to add led weights. Strict rules about handlebars so you cannot get into a good aero position easily etc.

These rules apply to racing bikes, not to bikes that are used everyday for commuting or recreation. If recumbents were so much superior to the classic diamond frame, they would dominate the non-racing-bike market. I rode enough recumbents to prefer my uprights when commuting in a city, also for mountain biking and rides through hilly areas. If a was commuting in a flat area outside of a city I would maybe consider a recumbent.

A recumbent isn't "superior" to a traditional frame. It has select improvements, but for the general consumer the ride quality of a traditional frame is much better.

The general consumer has never experienced a recumbent ride. If they had, they would find the recumbent more comfortable on longer rides.

For bumpy roads, you can always stand on the pedals on an upright bicycle and use your legs as shock absorbers. You can't really do that on a recumbent.

But the general consumer most likely doesn't want to spend too much money on a bicycle and recumbents tend to be a bit more expensive compared to uprights.

> the flying 200m speed record is 133km/h

Todd Reichert achieved over 144km/h in a Sep 2016 record (almost flat; average down-slope under 2/3 %)

cycling competitions (as all sport competitions) are about the sport not the technical innovations behind it.

UCI regulations are there to make a clear separation between sport and tech. given the latest advancements in engineering it's possible to render the athletic abilities of a person irrelevant. power to weight ratio is an important stat in cycling and there is serious physical preparation involved in the process of dropping a few hundred grams in weight before a competition. now imagine that instead of that you get the latest innovation in carbon frame design and drop that weight from the bike. tech wins. and that's not the purpose of sport competitions. F1 has similar regulations for the exact same reason.

also, these regulations address health and safety. some aero positions can affect a rider's stability and, in turn, can affect the security of other riders.

As far as I know the diamond frame is mandated by UCI for professional races.

Lots of improvements have been made on this. Google 'recumbent bike'. I drive past a guy most mornings in one of these things [0]. He is driving that thing summer and winter, rain or shine.

[0] https://billeder.velostrada.dk/wp-content/uploads/2015/12/M%...

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