On Friday, April 20, 2018 at 1:40:45 PM UTC+1, AMuzi wrote:
This is either s discussion of compliance/shock/flex or a
pile of text used as a reason for glitzy product photos

https://cyclingtips.com/2018/04/jra-...-still-matter/
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Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

It's a good, comprehensible, technical discussion of a very difficult set of interrelated, interacting, non-linear dynamic effects, drawing on the work of leading bicycle-engineering thinkers who grasp that engineering is more than mere numbers. It is also, obviously if unintentionally, a brilliant demonstration of how geometric marginality works in mature technologies: every unit of gain costs not the same amount of money and effort as the previous unit, but an increasing factor. It is also convincing proof that bicycles are already a pretty mature technology.

***
But the key here is that the usual clowns in cycling will gruffly dismiss the science, pump narrow tyres to the maximum pressure permitted, or over, and claim their street corner wisdom is superior to careful engineering development, and wreck what a near-geniuses like Damon Rinard achieved by decades of hard work. And on top of that they'll whine that harsh bikes ruin expensive components! Here's an example from yesterday on RBT:

Jute: "In fact, there are all kinds of really good reasons for inflating bicycle tyres to the lowest you can get away with short of snake bites."

Joerg: "Right, and then you get a pinch flat or snake bite which is often unfixable in the field. All it takes is one pothole. No thanks."

After that, with all the goodwill in the world, I just give up.

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I won't be rushing out and buying one of those bikes that feature a gazillion dollars of superb development to fix what in my mind is a bodge: What's wrong with those bikes, which they're trying to fix, is a consequence of narrow tyres which require very high pressure.

My Utopia Kranich stands at the pinnacle of the old-style engineering: an ultra-stiff frame running on 60mm wide tyres, such a huge volume of air at such a low inflation (2 bar, 29psi) that my triple helical sprung hammock saddle (Brook B73), the next softest spring on my bike next to the tyres, comes into action only when I storm an 8in kerb. Simple, straightforward, functional, and inexpensive for what it does and how it does it, and how long it has lasted, and is expected to last further, a couple of magnitudes of service life compared to a carbon bike. Considering all that, are you surprised I consider every new bike with tyres narrower than 47mm a bodge to be fixed?

***
All the same, I enjoyed an informed discussion, even if I'm not convinced of the necessity of the clever work behind it; knowledge is advanced regardless of the engineering intent. Thanks for the link.

Andre Jute
For that much benefit and entertainment, I don't begrudge the advertisements