On Wed Jan 1 12:08:00 2025 Frank Krygowski wrote:

Good article from Jan Heine on benefits of wider, softer tires for
absorbing vibration and lessening suspension losses:

https://www.renehersecycles.com/the-missing-link-suspension-losses/

At the time the rumble strip test was published, I expressed some
skepticism because its roughness is fundamentally different than the
random roughness of either a rough road or a gravel road. In particular,
the rumble strip is all "negative," cut into the smooth surface, while
rough or gravel roads have both "negative" holes plus "positive" patches
or rocks that protrude above the surface. One practical difference is
that when dealing with only "negative" roughness, higher speeds reduce losses. The opposite is true with "positive" roughness.

But I suppose for demonstrating the fundamental effect, the consistency
of the rumbles is useful. And the measurements seem valid as long as the
test speed is also consistent.

BTW, Jobst Brandt is mentioned in the article. I recall that in
discussing rolling resistance here, he insisted that "rolling
resistance" should be defined _only_ as the losses generated by tire
rubber's hysteresis. I disagreed, because that implied that solid rubber tires a la 1880, or near infinite tire pressure, or even metal rims with
no tire, would be best. Anyone who has ridden an antique solid tire
"safety" bike knows how slow those tires were.

Coming out of Niles Canyon, you have to ride at around 20 mph Because of traffic I was forced to cross a rumble strip with my 28 mm tires and came damned close to losing control but it did allow me to let 5 cars moving at 45 mph + get past before a
constriction. While you're talking about taking the lane why don't you come here and try taking the lane? You would soon discover, if you're lucky, from a hospital bed that California deivers don't like your ideas.

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