Re: [CR] Nylon tubulars

> Yes , but that's why riders and coaches have been adjusting pressure for
> decades to compensate for weather conditions.
> Cotton is not that flexy either.
> That's why it's silk for cement tracks and cotton for boards.
> That's why the tires are marked wet weather and all-weather, etc.
> That's why the board tracks recommend rubber based strips, instead of
> silicon, so the coefficient of friction can be maximized.
> That's why sew-ups are so much better cornering than clinchers, etc., etc.
> Ted Ernst
> ----- Original Message -----
> From: "donald gillies" <gillies@ece.ubc.ca>
> To: <classicrendezvous@bikelist.org>
> Sent: Friday, May 28, 2010 9:22 PM
> Subject: Re: [CR] Nylon tubulars
>
>
>> That photo of 'Raleigh Nylon Extra' tubulars is from a tire that's
>> rotted away, and for display only, so there is no danger of me riding
>> them (and even so, here in san diego we hardly have any rain.)
>>
>> Here's a theory about why nylon tires might be WORSE in rain. First,
>> vulcanized rubber is vulcanized rubber, whether it's vulcanized to
>> a cotton or nylon casing. HOWEVER, a fully inflated tubular with a
>> cotton casing may be more 'flexible' than a similar nylon casing tire,
>> which, at its maximum pressure, might be totally inflexible, like a
>> latex vs. butyl tube.
>>
>> So rain lowers the coefficient of friction between the rubber and the
>> road. However, the cotton tire is more supple and rides like a
>> squished sponge, so has a large contact area with the road and good
>> traction in the rain. A fully pumped nylon tire behaves like a rigid
>> body, with very little surface area on the road, and when you lower
>> the coefficient of friction for that small area, you pass some
>> handling or steering minimum friction point and the bike becomes
>> dangerous to ride?
>>
>> - Don Gillies
>> San Diego, CA, USA