Re: Science of cycling still largely mysterious

AMuzi <am@yellowjersey.org> wrote:

On 5/25/2025 1:45 PM, Wolfgang Strobl wrote:

Am Wed, 21 May 2025 19:17:51 -0400 schrieb Frank Krygowski
<frkrygow@sbcglobal.net>:
 

On 5/21/2025 4:13 PM, Roger Merriman wrote:

zen cycle <funkmasterxx@hotmail.com> wrote:

 
A full suspension bike is far more efficient over rough terrain in terms
of speed and comfort.

 
I dimly recall an article in _Bicycling_ magazine (before it effectively
morphed into "Buycycling") that documented the measured increase in
downhill speed of a suspended bike compared to a rigid bike. At that
time, it was an unfamiliar concept.

 
Problem is, some people generalize the fact that a good suspension
increases downhill speed on some undergrounds to circumstances where one
or all of these preconditions do not apply.  Suspension adds weight and
converts some of the potential energy to heat. When riding downhill,
additional weight has essentially no disadvantage, it might even help.
On rough underground and at speeds where air resistance is the main
parameter, helping the rider to hold a better aerodynamic position has
more effect than that little bit of energy loss.
 
Almost nothing of all that applies while riding on reasonably flat
ground or uphill.  Some modern wider tires have lower rolling resistance
than narrow high pressure road tires of the old and offer enough
suspension for most roads that aren't not completely broken.
 

 

Indeed doesn’t take a particularly rough gravel road for my MTB suspension
and tyres to make it a faster bike, vs the Gravel bike be that my times on
Strava or unfortunate Gravel riders on the Ridgeway etc.

 

And in the past few years, many people have realized that it takes very
little roughness to make wider, cushier tires valuable for increasing
speed.

 
Not necessarily. In recent years, some wider tires have become better in
terms of rolling resistance at lower pressure and without compromising
puncture resistance. It's not that people have recognized something that
has always been the case. The wider the better doesn't apply, either.
The optimum has only shifted a little, again.
 
Roads degrading faster due to heavier vehicles might be a reason, too.
 

Bumping the rider about has serious energy costs.

 
Of course.
 

 
 
Offroad cyclists (I am not among them) tell me that for all
suspension's weight and sloppiness, they cannot brake or
turn with a wheel in midair so suspension is necessary for that.
 

Even on the flat ground suspension is well fast, I regularly pass Gravel
folks on the Ridgeway which is one of the older roads in the uk, it’s not
technical it’s essentially a gravel road, but the MTB just flows and isn’t
kicked about like the gravel bikes are.

By that same token Gravel bikes with suspension do review well, though tend
to fail the spirit of Gravel test, which I do get, though equally my mates
bike with 30mm of travel and 45mm of tyres isn’t going to cope well with
the sort of terrain my MTB 130mm of travel and 64mm tyres allow.

Roger Merriman