wrote:
Mark my words wrote:

I watched the descent of the Tourmalet, the camera focused on a
lead breakaway rider pedaling hard at a cadence of 60-70rpm, with
the announcer claiming he was traveling at 60-65mph. [what size
sprockets does that take?]

Damned good question. I just took a downhill at 35 MPH upright on
a mountain bike with a 48/11 combo and could barely pedal that
fast, much less add any power or speed. The hill was about 12% to
15% and fairly short but no matter what the gears I could not
imagine pedaling slowly at 60-65 MPH. Maybe he was just moving his
legs to keep blood flowing. I admit to doing that sometimes on a
long downhill where trying to pedal would be a waste of time.

Having ridden the Galibier where Phil Liggett has in years past
claimed descending speeds of 60mph I am certain that was bluster,
because coasting as fast as possible I and my ride companion could
barely achieve 40mph, the descent not being steep enough to go any
faster. Even farther down, on the curvy, not steep enough,
Telegraph. From experience 60mph requires at least a 13% grade as
straight sections of the Fedaia and Rombo passes in Italy
have. In contrast, most roads that steep are not straight enough
for speeds above 35mph.

Beyond that, the strung out chasing field, all pedaling hard, are
apparently not shown in real time, because they appear to be
traveling over 40mph through curves without leaning into them
significantly.

Marketing!

No argument. I think a multiple gear arrangement would be needed
for anything much over 45 to 50 MPH, pro or not.

Check out last week's Men Pro Race at Massachusetts
Fitrchburg/Longsjo Classic on YouTube:

http://www.youtube.com/watch?v=L56BMBdjo1w.

The radar gun was calibrated by the police just before the event.
Many of the pros were riding 54 X 11 for the high speed descents

So! How do you achieve a speed like 100kmh+ pedaling that ratio at
60-70 rpm? I have coasted down the Fedaia and Rombo passes at over
100kmh with a 50-13 engaged, but not pedaling because I cannot spin at
a rate well over 120rpm and why should I? Just evaluating what power
would be required to affect such a speed makes the whole idea
preposterous.

Jobst Brandt


Kind of what I meant. My old Peugeot had maybe a 52/11 and I could not
keep up the cadence at 45-?? MPH at 15 years old going downhill so why
try? The few cars I did pass were on the steep sections of highway 9 and
I coasted by at about 50?? after drafting as close as I dared. You must
know that section of road since it is a popular place to get an 1,800
foot climb in and have a roach coach and a few guys on bicycles or
Harleys to BS with at the top. I rode a motorcycle up once and dumped it
on a small oil patch making a left turn to the Harley crowd at maybe 3
MPH and they all laughed their asses off. Major embarrassing but a few
of them admitted to really dumb things happening to them too. One guy
had his leather jacket tucked behind his seat and it got caught in the
rear tire at 45 MPH and took him down, so I am not the only one with
random bad luck.
Summit road is a nice ride but going down Big Bear road can be deadly
due to the switchbacks. Too bad it dumps out onto highway 17 and I had
to ride back up.
I think you know the roads.

Cheers,
Bill Baka