Originally Posted by
Polaris OBark
Maybe it is best that it remains a mystery.
Anyway, wrt post 275 etc, the main point is someone formulated the hypothesis, and put it to the test, and appears to have refuted it.
That gives (at least) three logical possibilities:
(1) The planing hypothesis was successfully refuted.
(2) The planing hypothesis was wrongly, or too stringently, formulated, so what was being tested really wasn't the original hypothesis.
(3) The experiment wasn't done properly (for example, maybe putting the bike in the trainer prevents planing), not enough subjects, etc.
I do agree it would have been more compelling if someone who appears to have benefited from planing had been a test subject.
However, if you want to assert anything other than (1) at this point, the burden of "proof" is placed on the shoulders of whomever wants to save the hypothesis. I still think there might be something to it, but I am less enthusiastic about the idea than I was 4 days ago.
My initial interest was whether a bicycle that exhibits planing could become a non-planing or even anti-planing bicycle by changing something reproducibly (like an elastomer or isospeed coupler setting, or even the length of an inserted seat-post.)
Or maybe;
4) None of the bicycles has frame flex characteristics optimized for the rider(s).
And there's this:
Jan Heine, Editor, Bicycle Quarterly says:
December 31, 2014 at 8:24 amYes, suspension can have the same effect. We once tested a Trek 2100C with an elastomer in the seatstays. It came with three elastomers. We made a forth insert out of delrin that had the effect of no suspension at all. The results were interesting: Without suspension, the bike felt like an inexpensive oversized aluminum frame: dead and hard to get moving. Same with the stiffest elastomer. With the medium elastomer, the bike was transformed, and it climbed really, really well. With the softest elastomer, we couldn’t get in sync with the frame.
The elastomer was only about 40 mm (1.5″) thick, so the actual movement of the rear triangle was less than a centimeter. It appears that most suspension systems have too much travel to be beneficial for planing. Still, the idea of being able to tune the amount of frame flex on your bike holds a lot of promise. Imagine if you can use a stiffer elastomer for a fast group ride with friends, but a softer one for a 1200 km brevet. Or even change elastomers at the mid-point of a long-distance event as you get tired.
Before I ever heard of planing I had an aluminum road bike with 700cx26 tires and a 31.8mm seatpost. This combo was hammering my back on long rides, I saw the fitter at the shop where I worked and he swapped out the 31.8 seatpost for a shimmed 25.4mm post. This helped my back quite a bit and had the unexpected benefit of improving the ride feel immensely. I wouldn't go so far as saying the bike now planed, but seating pedaling, especially hard climbing efforts felt much better. I could stay seated longer before having to stand, for instance..