On 2018-04-18 18:16, Andre Jute wrote:
On Wednesday, April 18, 2018 at 6:02:49 PM UTC+1, Joerg wrote:
Just received some 25mm Vee Rubber road tires and it says 7bar
100psi max on the side. That's a bit low for my taste.

The Zafiro I have on there now says 100psi min and 130psi max which
is more up my alley.

By how much can a low max rating be exceeded? I like 100-115psi on
my road bike in back. On the front I won't exceed the max because
a blow-out would be nasty and that carries less weight anyhow.

-- Regards, Joerg

http://www.analogconsultants.com/

Is this some new California fad, riding offroad on narrow rubber?
Whatever for? BTW, I have no problem with low- or zero-tread tyres
because I ride mainly on tarmac, even in the narrowest lanes, but
surely a mudplugger wants considerable mechanical grip.


No fad but road bikes out here must cope with road sections that are
either gravel or dirt. Part of life.


There's a good reason not to blow up tyres over the max
recommendation: It can get pretty nasty and expensive when
overinflated tyres blow the rim apart. It is well worth reading Andy
Blance, the designer of Sheldon's beloved Thorn bike, on tyre
inflation: see page 36 at
http://www.sjscycles.com/thornpdf/th...a_brochure.pdf


It's a 30+ MB file and their server seems to be on an old dial-up line.


I was a convert to comfortable suspension and inflation regimes
already in my motor-racing days, and achieved the same results the
same way in cycling: see
http://thorncyclesforum.co.uk/index....16360#msg16360
(which is an extended version of a reply I first made on RBT to a
query by Pete Cresswell) and read on in the ensuing very
well-informed engineering discussion about ways of determining the
optimum tyre inflation.

In fact, there are all kinds of really good reasons for inflating
bicycle tyres to the lowest you can get away with short of snake
bites.


Right, and then you get a pinch flat or snake bite which is often
unfixable in the field. All it takes is one pothole. No thanks.


... I run my bike on 60mm Big Apple Liteskins inflated to 2 bar,
which is about 29psi and I had two flats in 8500km, by which time the
tyres were perhaps half worn. One of those was a snakebite when I hit
a pothole at the bottom of a hill at 51kph when the tyres at the end
of the month-long reinflation interval were probably down to 1.5 bar,
and the other was a nail I picked up by going into an industrial
building site to ask the workmen to show me their battery-operated
angle grinder (which is a threat to locked bikes).

AJ Both flats happened right after I announced that in 10 years on
Big Apples I never had a flat...


The turf here is "slightly" different from the UK.

I found that riding close to max allowed pressure serve me best. On the
MTB it also results in less side wall damage.

--
Regards, Joerg

http://www.analogconsultants.com/