Re: Fw: [CR]Tyre/tire size for 27 1/4 Dunlop Special Lightweight rims

(Example: Books:Ron Kitching)

In-Reply-To: <003801c84335$a512f5b0$4001a8c0@compaq>
References: <003801c84335$a512f5b0$4001a8c0@compaq>
Date: Thu, 20 Dec 2007 16:31:07 -0500
To: "David Snyder" <dddd@pacbell.net>, "Classic Rendezvous" <classicrendezvous@bikelist.org>
From: "Sheldon Brown" <CaptBike@sheldonbrown.com>
Subject: Re: Fw: [CR]Tyre/tire size for 27 1/4 Dunlop Special Lightweight rims


Quoth David Snyder:
>I can't believe those "1-inch" tires are the width equivalent of what is/was
>sold here with that stated sizing. All the 27X1" tires I've seen measure
>all of just 20mm, apparently contrary to the photos and well less than the
>23mm rim width. Am I missing something?

See: http://sheldonbrown.com/tire-sizing.html#dishonest

The Dunlop Special Lightweight rims were the hot ticket in their day (early '60s) and were probably the finest steel rims ever made.

They were designed to mate with the Dunlop HPRR ("High Pressure Road Racing") tyres, which were nominally 1 1/4, but actually narrower. When these were available, they were in a class by themselves, no other clincher tyres came anywhere near them in quality and performance.

In the mid-60s, Dunlop got into a urination contest with Raleigh, and wound up discontinuing the manufacture of bicycle tires. For a couple of years after that, we got very good at "booting" damaged HPRRs, 'cause a half-worn-out, booted HPRR was still better than anything that could be purchased new!

Fortunately, in the later '60s, the Japanese got into the game, and started making even better tires.

The HPRR tread pattern was copied by Schwinn for their "Schwinn Puff" tires.

Mark Battley inquired:
>What is a suitable size tire to use on 27x 1 1/4 Dunlop Special
>Lightweight rims

Actually, it's a misnomer to speak of "27 x 1 1/4 rims." The 1 1/4" refers to a tire size, not a rim size. No 27" rim I ever saw was anywhere near that wide. Rim manufacturers did sometimes mark the rims that way to indicate that they were compatible with the then-ubiquitous 27 x 1 1/4 _tire_ size.

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