On Sun, 27 May 2018 09:48:48 +0200, Emanuel Berg
wrote:
Tim McNamara writes:

Great only too expensive, especially compared to the Fuji and in
particular the amount of money in my wallet. Why do they do
randonneurs with 32 tires anyway?!

Comfort, for one thing. The standard brevet lengths are 200, 300,
400, 600, 1000 and 1200 km. All with time limits, checkpoints, etc.
The extra comfort afforded by the larger tires becomes very helpful
after 8, 10, 50 hours in the saddle.

Ha ha Definitely. But why not 40 or 47 tires then? They are not
that much slower/heavier or less aero than 32 and even more
comfortable. Especially with a loaded bike I think 32 is too thin. But
if that's the way it is I'm not letting it stop me from going, of
course.

Many people have toured all over the world on 700 x 23 or close tires.
Suboptimal to my thinking, but then it depends on the load you are
carrying. Igor Kovse, probably the chief evangalist of ultralight
touring, rides a bike that fully loaded weighs less than many people's
unloaded bikes. He's taken that setup through the Himalayas, etc. But
if you have 50 lbs of gear, using 23 mm tires is just making like hard
for yourself.

Tire width is a center of discussion in the randonneuring world. 700 x
~30 versus 650B x ~40-45 versus 559 x 50+. Of course, that world is a
tiny handful of riders, relatively speaking. The current trend is
towards thinking wider cushier tires are a net performance benefit. Of
course, in that crowd "wider" is often considered to be 40+ mm, not 25
mm as in the bike racing crowd.

There is a tradeoff with weight. A 44 mm wide tire in 700C weighs more
than in 650B or in 559 BSDs. So the bigger hoops tend to be shod with a
bit narrower tire and teh smaller hoops tend to have wider tires. It's
fairly easy to end up with very similar overall diameter wheels with the
smaller tires on the bigger rims and the bigger tires on the smaller
rims. The wheels' relative interia ends up being pretty similar.

650B x 40+ was the standard for brevet riders until the early to mid 50s
when the fastest riders were riding PBP on what were basically racing
wheels. Improved pavement and improved tires were a big part of that-
until the post-war reconstruction of Europe, it would not have been a
surprise to find 1/2 or more of a brevet on dirt roads or gravel.
Post-war Europe upgraded a lot of rural infrastructure much like the
Eisenhower interstate system, to make sure that troops and materiel were
readily transported in defense of the nation.

Narrower tires were believed to be faster, a common notion today, and
smoother pavement allowed the use of those tires and a perceived
benefit. A few decades ago, Jobst Brandt and the Avocet folks published
data suggesting that narrower = faster wasn't necessarily so. More
recently, Jan Heine has gone after that notion with a vengeance in his
publication and his product line (Compass Cycles) which makes high
quality high performance wide bike tires aimed primarily at the brevet
type or adventursome rider.