Re: [CR]testing quality


Example: Racing:Wayne Stetina

Date: Thu, 13 Mar 2003 14:32:24 -0600
Subject: Re: [CR]testing quality
From: Todd Kuzma <tullio@TheRamp.net>
To: Grant McLean <Grant.McLean@SportingLife.ca>, <classicrendezvous@bikelist.org>
In-Reply-To: <A5E72E8AE73AD311954A009027887CFFC39311@SLSERVER>


on 3/13/03 2:15 PM, Grant McLean at Grant.McLean@SportingLife.ca wrote:
> It's one thing to test prototypes, and quite another
> to insure safety and reliability in production.
>
> It seems all manufacturers test, yet bike shops have
> their experience with cracked, broken, and bent frames.
> Where's the problem come from? Is it that there isn't
> enough margin for manufacturing variables, or are the
> standards just not followed in production?

I think that it's more than that. I think that many of the tests performed do not accurately simulate real world use. Additionally, riders will often subject their bikes to conditions not anticipated by the designers.

Recently, Specialized had a recall on certain full-suspension bikes equipped with disc brakes. A number of stays had broken in use. Apparently, what was happening was that riders were jumping bikes off ledges or other obstacles and locking the rear disc while in the air. With 4 foot drops (the number I was given by Specialized) and a locked rear disc, a significant force was transmitted to the stays upon landing. Specialized designers simply didn't anticipate this so they had to redesign the stays.

One thing that is good about lugged, steel road bikes is that we know a lot about the common uses, failure modes, production methods, etc. because of decades of collected experience. This provides some degree of comfort for small builders who may not have the resources to conduct extensive failure testing of their products. Sticking to the classics means sticking to what is known.

Todd Kuzma Heron Bicycles LaSalle, IL 815-223-1776 http://www.heronbicycles.com