Commuting - Conti Contact SECURITY - one tire, two max. pressures ??

"The Contact Security is designed for commuters who simply can't risk a puncture; people who want a no-hassle ride to work when speed and rolling resistance is not an issue. This tyre is therefore heavier than the other Continental city tyres due to the Security layer under the tread (see diagram). Due to the thickness of this layer, the likelihood of urban detritus penetrating the tread is minimalised. The compound we have used for the Contact Security uses a mix of carbon and silica as the main agents. Carbon aids tread life whilst the silica boosts grip levels."

"The utmost in safety thanks to an extra thick puncture-proof breaker. Designed for industrial applications, the ContactSecurity can also perform well in everyday use. Its massive puncture-proof breaker was developed to resist metal cuttings and shards on factory grounds. In view of its tough construction, it is not a comfortable touring tyre with low rolling resistance, but it does effectively ward off gravel and shards on short stretches in the city."

You can't say they didn't warn you that it's best suited to riding around steel works !! So if your tires are taking a beating from desert thorns, broken glass or metal debris etc this might be the one to try.

The only problem is WHO do you believe about the maximum recommended pressure


The Conti German website site shows 70PSI max for 700 x 37c

http://www.conti-online.com/generator/www/de/en/continental/bicycle/themes/tires/city/contact_security/contact_security_en.html

But

http://www.conti-tyres.co.uk/conticycle/ti%20contact%20security.shtml

The UK site shows 85PSI max (possible typo error by webpage designers??)

Since I first posted this, Conti UK confirmned 85psi a Conti Holland said it's 6 bars - or 87 psi. So you could get away with 90spi into the bargain.

What the Dutch guys did say: is with the heavy puncture resistant breaker layer it's always best to run at MAX pressure to avoid damage to the sidewalls - which from many posts seem to be where Conti users have damage issues on many models. Possibly because they run on the low end, or under inflated.

If you believe the late Sheldon Brown, the actual max pressure is probably greater than 70 or 85 psi, with thouse numbers being pressures that are substantially derated for a margin of safety. I am thinking how maybe the tires being sold in Germany are different from those sold in the UK as well.

You can pump the 28's and the 32's to 100 psi. That tire has a fairly loose bead, so I wouldn't put it over 100 without fear of it jumping off the rim.

If you believe the late Sheldon Brown, the actual max pressure is probably greater than 70 or 85 psi, with thouse numbers being pressures that are substantially derated for a margin of safety. I am thinking how maybe the tires being sold in Germany are different from those sold in the UK as well.

Maybe Germany just has better lawyers.

You can pump the 28's and the 32's to 100 psi. That tire has a fairly loose bead, so I wouldn't put it over 100 without fear of it jumping off the rim.

It's the 700 x 37c ratings where the pressure discrepancy between web pages shows.

These are wire bead tires (and if you believe Conti's claims - virtually indestructable) so by design and construction they're not going to be easy to get on - or off.

My main worry would be blowing a hole in the sidewall. Although I guess you could assume they build in at least a 10% safety factor, if not 20% in the maximum pressure rating. But running a tire at 30% over its max. rating for it's entire life will surely reveal any manufacturing defects in a spectacular and most inconvenient way..