Re: [CR]Re: Manufacturing processes; Was Aluminum bikes, then aerospace roots, now going nuclear

(Example: Component Manufacturers)

Date: Tue, 22 Jan 2008 11:17:01 -0600
To: classicrendezvous@bikelist.org
From: "Mark Stonich" <mark@bikesmithdesign.com>
Subject: Re: [CR]Re: Manufacturing processes; Was Aluminum bikes, then aerospace roots, now going nuclear
In-Reply-To: <a062309f1c3bbc9d3044c@[192.168.1.33]>
References: <752788.27385.qm@web55901.mail.re3.yahoo.com>


Those CNC'd hubs usually had the pawls in the hub shell, operating with a much larger radius and therefore lower loads than the Shimano pawls, inside freehub the body. Often they had more pawls too. Didn't take a rocket surgeon to see they *should* be more reliable.

My son and several of his friends had completely tricked out MTBs at the time. He bragged his was 100% Shimano free. They formed the "University of Minnesota MTB Club" so they could borrow a U of M van and trailer and head to Moab for spring break. After the 1st year they learned to take a few Shimano hubbed wheels along, for when the fantastic grip and lowest gear grades caused their wunder hubs to go belly up.

I'm not a fan of a lot of Shimano's components, but they do control the entire process. Going outside for stuff like heat treating leaves room for trouble. I'm sure the CR-timeline small builders had to farm out a fair amount of that sort of thing, so I assume they were very vigilant about QC.

At 1/22/2008 08:41 AM -0800, Jan Heine wrote:
>>CNC!!!! Eeek!!!! Okay, maybe I'm just clueless, but when I think
>>of CNC, I think of all that dreadful 1990's small batch
>>manufacturing that gave us Kooka cranks, Paul's derailleurs and the
>>like. It started in the MTB market and infected the road market.
>
>> they also just kinda sucked. I think Shimano put it best in one
>> of their ads that read something like: "Yes, we make CNC machined
>> parts from aluminum alloy billet. We call them prototypes." I
>> think declinig costs of CNC equipment was the pathway that allowed
>> a lot of self-annointed parts engineers to make expensive junk on
>> a small scale. Quaility bike parts are better made using hot
>> pressing, or forging techniques that bring the part close to final
>> shape prior to machining.
>
>Different manufacturing techniques are applicable to different
>components. The problem of many small shops is that they master one
>technique and apply it to all their products.
>
>CNC machining may be fine for hub shells and headsets, but it is
>less suitable for cranks and brakes. Today's small makers get around
>that by beefing up their parts. A CNC-machined Paul Racer brake
>weighs 50% more than the forged Mafac model...

Mark Stonich;
     BikeSmith Design & Fabrication
       5349 Elliot Ave S. - Minneapolis. MN 55417
            Ph. (612) 824-2372 http://bikesmithdesign.com
                        http://mnhpva.org