SJP

Bike of Theseus.

@phops: I am very skeptical that brake hose expansion provides meaningful contribution to flex in the system compared to just about any other flex. For example, since piston area at the caliper is dramatically larger than the master cylinder area at the lever, flex at the caliper has to be a much bigger contributor, since it is multiplied both by the piston area/master cylinder ratio and by the lever travel/master cylinder travel ratio. If brake hose expansion had a noticeable effect on lever travel at all, it would be twice as large for the rear brake as for the front brake, because the rear brake line is twice as long as the front. I have never heard anyone mention this as a problem. As to the automotive example, automotive hoses are just rubber, they have no steel braid. They tolerate much larger fractional volume expansion by design.

You need a bigger screen.

That one is terrible. Because of the orientation of the banjo fitting near the head tube, cyclic loads on the hose due to steering will tend to loosen the mounting bolt. This is a bad idea.

@sanchofula: OK, someone has to explain to me why the integrated hard brake lines are good. Seems like they increase weight, complexity, time (and thus cost) of assembly, and number of potential points of failure.

It is spectacular. And not torsionally flexy at all. Not at all.

Well, he needs *A* significant other.

@johnnys2010: Only hand tools allowed, of course. But more seriously, there is a continuum between hand-made and manufactured at large scale, and the line between them is arbitrary. Etsy has this problem too.

I like that the opening image for an article about a bike show ostensibly all about "hand-made" bikes is an obviously CNC-machined link. That means someone drew up the shape on a computer and then put a block of metal into a machine that made this piece.

This is pretty telling about the difficulty of modern World Cup XC courses: Elite Men's Winning Average Speed: 19.845 km/h That is 12.4 mph. Around here (Eastern US) on an XC course, the fast NICA racers and Cat 1 racers will average >14 mph. Of course, for safety reasons, the World Championships XCO course will be notably easier than the World Cup courses. This is because the World Cup is invitation-only for the best riders, but for the World Championships they have to accept riders from every country (many of whom really aren't all that good). This means people like van der Poel and Pidcock, who don't spend nearly as much time as the World Cup regulars on an MTB, have a relatively better shot than at a World Cup, because fitness is relatively more important than bike handling and MTB-specific efficiency.