Re: [CR]evolution of chainring bolts

(Example: Framebuilders:Brian Baylis)

In-Reply-To: <437FD1C8.16469493@earthlink.net>
References: <111920052014.1207.437F879E000A4480000004B7220699849903019B09010C9B0E00@comcast.net>
From: "Bob Reid" <robertrreid@tiscali.co.uk>
Subject: Re: [CR]evolution of chainring bolts
Date: Sun, 20 Nov 2005 10:29:26 +0000
To: CR List <classicrendezvous@bikelist.org>


Translated from the French patent (applied for 17th November 1959, granted 16th August 1961) relating to the Italian patent of 19th November 1958. ---------- "This invention refers to a wheel of pedals with double gears with crank for bicycles, which, contrary to those currently in use absolutely avoids in any way any incident of tangling the transmission chain, as well as in the event of fall in the course of assembly. Apart from that, the bodies of fixing of chainwheels with the spokes of the crank are protected from shocks that might reduce their robustness or compromise their operation and are placed so as to prevent any interference or catching with objects of any kind which can possibly be near them, whilst allowing fast and perfect cleaning of the cranks and by reducing to he minimum the transverse obstruction of the cranks so that, when one wants to provide the transmission with a housing, this one has small dimensions.

The improvement consists primarily of the external faces of the chainwheels and those of spokes of the cranks forming single planes with the faces of the parts connecting and assembling the aforementioned chainwheels and spokes.

This method of connection can consist of hollow screws crossing the crank and chainwheels, being screwed one in the other, and are provided with heads that are completely recessed in the corresponding holes formed in the thickness of the chain wheels on the visible side; the aforementioned screws are formed so as to be able to be screwed and and unscrewed with tools normally of everyday usage.

With the goal of reducing to the minimum all projections or recesses, even the opening of the pedal hub on the end of the crank, is closed by a small pressed lid threaded on the outside and with a polygonal central hole for the introduction of a tool for screwing and unscrewing." ---------- My own reading of this is that it came about primarily from the problem of the chain getting snagged on the "typical of the day" bolt heads. The extra bits about ease of cleaning the cranks - from the use of recessed bolts and pedal cover, looks to me like Tullio expressing the Ettore Bugatti side of his character !

What I will need to try and follow up on - and if anyone else has any ideas speak up - is at what point Tullio lost the exclusivity of the recessed allen key fixing (bearing in mind he patented the flush fixing (typified by the hollow screws)... and who was next ?

Bob Reid Stonehaven Scotland

http://www.flying-scot.co.uk (mapped)

On 20 Nov 2005, at 01:31, Chuck Schmidt wrote:

Tom Martin wrote:
>
> How did the current chainring bolt come into it's current form?
> The reason I ask is I've skinned my knuckles for the xxxx,000 th
> time. Yes, the appropriate way to remove or tighten chainring bolts
> is to put the chain on the largest ring. But what if you are
> assembling the rings off the bike, outside of the factories what
> have all sorts of fixtures to hold the inside nut thingy with 2
> slots on either side.
> Each time, I've wondered who designed this type of nut/bolt for
> that specific apllication, and why??
> And how come there hasn't been a more suitable alternative that
> would make much more sense?
> Am I crying over spilled milk?
>
> Tom Martin
> Oakland CA


> From the Campagnolo Timeline at <http://www.velo-retro.com>: "1958 - The Record 5-pin cotterless crankset is introduced; 151mm bolt circle, 44 tooth minimum chainring, pedal dust caps, relieved spider and raised pedal lip. Also introduced are the Record one-piece alloy, small and large flange hubs (oval holes in flanges, oil hole clip and open "C" on quick release lever changed to closed "C"). Patent is granted on hollow chainring bolts with Allen key hole and crank bolt cover with Allen key hole."

Tullio designed it, patented it; very light and designed for ease of assembly. The design has certainly stood the test of time. I always plan where I place the Allen wrench in relation to the crank arm and use that for leverage, with one hand grasping both the wrench and the arm. Never skinned my knuckles doing Campagnolo chainring bolts in 30 years.

I believe Tullio was the first to use Allen bolts on a bicycle; 1951 on his Gran Sport rear derailleur. If there was a better idea for chainring bolts I would think someone would have come up with it in the past 46 years, right?

Chuck Schmidt South Pasadena, Southern California

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