Re: [CR]Re Lugless frames/ bilam/performance

(Example: Framebuilders:Pino Morroni)

To: mountgerald@btopenworld.com
Date: Fri, 21 May 2004 19:59:01 -0400
Subject: Re: [CR]Re Lugless frames/ bilam/performance
From: "Richard M Sachs" <richardsachs@juno.com>
cc: classicrendezvous@bikelist.org

hi mark. i think i should have reeled in my remark: "studys on this stuff do not exist."

i apologize for trying to be so sweeping in my statement. i knew that there were folks that analyzed data: your text here addresses some. reynolds also accumulated info to conclude which builders could pass their stringent 753 levels. bicycling magazine had the tarantula that gary klein made. damon rinard did his stiffness thing. etcetera.

i'm sure there are others. e-RICHIE aka Richard M Sachs chester, ct

On Sat, 22 May 2004 00:20:13 +0100 "Mark Stevens" <mountgerald@btopenworld.com> writes:
> Marcus Helman wrote:
> By worse I meant more prone to failure, poorer performing (I know,
> probably subjective too). My point is that you raised the issue of
> the
> tubes having the potential to be overheated. Do theses frames tend
> to exhibit the characteristics of having been built with too much
> heat?
>
>
> studys on this stuff do not exist.
> it's all conjecture - my take on it is that the decorations
> are the builder's attempts to dress up a plain looking joint.
> e-RICHIE
> aka Richard M Sachs
> chester, ct
>
> Richie, there was a study carried out by National Physical
> Laboratory,
> Teddington England on behalf of Gillotts. They were marketing their
> "
> L"Atlantique" at the time and reproduced these results in their
> circa 1950
> catalogue.
> Quote;
> About the Famous "L'Atlantique"
> For too long welded frames have had a bad reputation _ and in truth
> many of
> those produced deserved the stigma. Too often they were badly made
> without
> thought of the particular requirements a lug-less frame needed and
> frequently the skill of the maker left much to be desired. We knew
> that this
> state of affairs was unnecessary and that properly made a welded
> frame was
> the equal of the more orthodox lugged frame. In introducing the
> famous
> "L'Atlantique" three years ago we demonstrated our faith, which has
> been
> amply justified. Today it is firmly established as the finest welded
> frame
> made, worthy to stand on its merits equally with its stable
> companion, the
> famous connoisseur lugged frame. Not only does the National
> Physical
> Laboratory support our opinion, but riders have also proved it in
> the only
> practical way they can- by hard riding over along period.
> All our welders hold A.I.D Certificates and they are specialists
> in cycle
> frame construction. This fact, combined with the special 531 tubing
> we use,
> is the reason why the "L'Atlantique" is so popular today. Here is
> the
> reproduction of the report from the National Physical Laboratory.
> ________________________________________________________________________
> Engineering Division report.
> On a bend test on a cycle frame joint supplied by Messrs Gillott for
> |Good
> Cycles Ltd. 179-181 Southampton Way. London SE5 for whom the test
> was made.
> Authority for test; Application form dated 22nd September 1948
> N.P.L. eng,. test mark SJA
> The material submitted for test consisted of a brazed cycle frame
> joint,
> made from 2 steel tubes, set at an angle of about 100 degrees to
> each other.
> One of the tubes was about 20 inches long by 1 1/8th inch outside
> diameter
> by 0.025 " in thickness, while the other was about 5 1/2" long by
> 15/16ths
> inch outside diameter by 0.072 inch in thickness.
> The object of the test was to determine the strength of the joint
> under a
> bending load.
>
> Method of Test.
>
> After ends of the short tube had been plugged with steel bar for a
> length of
> 1 1/2 ", it was clamped to a sloping member of a testing machine,
> so that
> the longer tube was horizontal.
> A vertical pull was applied to the end of the latter tube , by
> means of
> a 1 ton hoist, loading through a calibrated spring balance, in such
> a manner
> that the brazed joint was subjected to a gradually applied bending
> moment.
>
> Result of Test.
>
> At a load of 160lb ., applied at a radius of 21" , the thinner tube
> buckled
> at a point 3 inches outwards from the joint.
> With the object of producing failure in the joint itself a
> length of
> the tube containing the buckled area was cut and replaced by a
> solid steel
> rod fitting tightly adjacent to the joint terminated about 1/2" from
> the
> edge of the joint. On reloading this composite structure a pull of
> 220lbs
> applied at a radius of 20" caused fracture of the same tube on the
> tension
> side at a point 1/4" from the edge of the joint.
>
> Date: 23rd October 1948 C.G.Darwin.
> Director
> Reference: Eng.Div./SJA/PLT/T.33 D.G. Sopwith.
> Superintendent
>
> _________________________________________________________________________
>
> I dont know of any comparison tests for Bi lam frames but imagine it
> would
> yield similar results.
> Mark Stevens Dingwall.