Re: [CR] Phil disk brake, Vitus 172


Example: Framebuilders:Jack Taylor

From: "Ted Ernst" <ternst1@cox.net>
To: "Jim Merz" <jameshmerz@gmail.com>, "Harry Travis" <travis.harry@gmail.com>
References: <8098104.106281.1278338642931.JavaMail.root@vms069.mailsrvcs.net> <08E1D97A-259C-4719-A42D-A59E61F0CA7E@mac.com> <DD4CC34FA0C344B9864304842BF815ED@D8XCLL51> <AANLkTimU4JVKLavQGUh3P2Id5ecTZVBPeusQ0kwVeDxk@mail.gmail.com> <AANLkTikld6QdODPr2C03aMnC_CExsMGj8tWKQWnqkp7y@mail.gmail.com>
Date: Mon, 5 Jul 2010 20:23:55 -0700
Cc: JB Froke <jbfroke@mac.com>, hmsachs@verizon.net, classicrendezvous@bikelist.org
Subject: Re: [CR] Phil disk brake, Vitus 172


Perhaps. But those are the terms in use during the '40/'50's and into the '60's for want of a more sophisticate understanding of the science and metallurgy of the tubing and process. This goes back to before Eddie M's time , too. Just kinda bringing the era when many of these things were discussed into life for the younger guys. Gives everyone a more intimate feel of how things were perceived in the day when these trusty steel horses horses were built and now so cherished by our group. Forgot to mention before that we always understood that the Phil disc was used in conjunction with a caliper brake so that the combined braking power didn't overwhelm the individual units. So many bike had three or four brakes. Gave the riders the regular brake and then a "drag" brake for situational use and also an emergency brak or two as it were. My wife and I had no problem stopping with Campy caliper brakes only on our old then new(er) Gitane / 531 / all Campy equipped bike. Only weighed 36 # at that time, not to bad at all!. Ted Ernst Palos Verdes Estates CA USA ----- Original Message ----- From: Jim Merz To: Harry Travis Cc: Ted Ernst ; JB Froke ; hmsachs@verizon.net ; classicrendezvous@bikelist.org Sent: Monday, July 05, 2010 8:06 PM Subject: Re: [CR] Phil disk brake, Vitus 172

Not sure what your point is here. I guess you are bringing up the question of frame getting "soft" from use. I think you can put this into the category of old wife's tale. The stiffness of a steel tube is based on the outside diameter and the wall thickness. Improving the tensile strength from alloys or heat treating does not change the stiffness, and putting the tube through use does not detract from the stiffness either. The only things that would reduce the stiffness of a built frame is if it is cracked, or that the wall thickness is reduced from rust. The benefit from using a very high tensile steel such as 753 is that a strong rider can flex it quite far without yielding it. But it is not "stiffer" than a frame made with the same gauge and diameter of 531. It will also resist buckling much better from hitting bumps and other impacts. Maybe the tale was started so pro's could get a new bike every year!

Jim Merz Big Sur, CA

On Mon, Jul 5, 2010 at 7:10 PM, Harry Travis <travis.harry@gmail.com> wrote:

Ted: Will I find in your or selected other CR listers' or other engineers' remarks more on the wear of steel frames? Re:The "soft" , but not in "softening"

>From the Wikipedia Reynolds tube entry (put here just for newbies like me,)

653 - Was a mixed tubeset which combined tubings of different steels; made up of 753 stays with 653 main tubes and 531 forks [7]. Following feedback from Eddy Merckx that a pure 753 frame was too harsh for certain stages of the Tour de France, Reynolds produced a 653 tubeset which combined 753 stays with 531 main tubes and forks[citation needed]. The 531 used was a thinner gauge than usual, produced specifically for use in the 653 set[citation needed]. Eddy and other riders were very pleased with the result, which combined a light, ultra-stiff and efficient transmission with a more forgiving and comfortable ride[citation needed].

[7] Tony Oliver, "The Touring Bike"

I know you are only reporting supposedly well-informed gossip. But, it is from teen agers and guys in their twenties, few of whom could not have wanted new gear and envied those favored with such.

In the religious wars over frame materials I've just not seen the report you offer here, in passing. For that matter, and this is even on-topic, I asked on bike.rec.tech whether anyone would report having replaced AND DESTOYED a functional aluminum handlebar of many years use, just because it was old enough and used enough to be suspect of being near the end of its fatigue life, and nobody affirmed he had done so.

Harry Travis
Pine Barrens of NJ
USA