Showing posts with label metal fabrication. Show all posts
Showing posts with label metal fabrication. Show all posts

Tuesday 25 November 2014

The F Word: Frame Building Fact and Forum Folklore








Highly skilled metal working, though frame building in particular has always fascinated me. Most cyclists will share an interest in bespoke products at some level and once upon a time, towns and cities could take their pick of craftspeople.

Sadly, these days every online community has its resident “experts” some of whom couldn’t manage joined up writing, let alone differentiate lap weld from lap dance.

One commentator recently asserted Reynolds 531 is a low grade Cro-moly. Arguably superseded in sporting terms by 725, 921 et al, it still offers excellent ride characteristics and suits a wealth of applications from Audax to heavily laden touring.

Indeed, many framesets are truly a ’la carte-blended from different tube sets to deliver just the right characteristics. There are no short cuts. Any fool can blast metal together with heat understanding their relationship and translating this into competently engineered, fit-for-purpose structure requires considerable time and practice.

Contrary to popular forum folklore, the main reason for 531’s obsolescence boils down to manufacturing techniques, technology and consumer expectation. Giant’s ground breaking TCR semi/compact geometry concept divided opinion but meant production bikes fitted much better, especially those of us with a more feminine dimensions i.e. proportionally longer legs and shorter torsos.

Hence, fillet brazing became standard practice amongst custom builders, while mass production has favoured TIG for the past twenty five years. Since 531 cannot withstand fusion welding, the mixture was tweaked and 525/520 conceived.

These “lowlier” tubesets along with in-house blends of 4130 still enjoy a responsive, engaging ride quality but at a very affordable price-arguably perfect for starter race mounts, or indeed winter/training.         

“Ghost building”; batch producing framesets to shop specifications and under their name has been a popular staple for many sole traders. However, even this has been dwindling recently. Increasingly custom builders are designing and fitting frames here before commissioning fabrication to Taiwan.

Material choice is also far greater than ever before. Steel has seen meteoric revival, having fallen from favour during the 1990s but now competes alongside various grades of aluminium, carbon/composites and of course, titanium. These also require a very different skillset, not to mention tooling.

Therefore remaining competitive alongside volume producers, especially those in the Far East is almost prohibitive without outsourcing somewhere along the line.


Fifteen years back, having completed another professional qualification and feeling distinctly disillusioned within day jobs; I decided it was time to seek professional training in welding practice. Armed with some elementary, plain gauge 4130 tubing, I spent many hours under the close scrutiny of a giant scots’ toolmaker called George and Terry; a chirpy, straight talking coachbuilder.

Ultimately, while said Cro-moly boasted livelier characteristics, high-tensile steels such as Peugeot cycles’ HLE or electricians’ conjugate were of comparable weight, cost pennies and proved much easier to fusion weld.

Undesirable for frames perhaps but I was seeking to build a series of low-slung, single wheeled touring trailers with a view to small scale production. Prices cannot be levied upon creativity and skills development but attempting this as a commercial venture would be a fools’ mission given the prices of superior, mass produced imports.  

Spleen vented and KA’s fresh MOT certificate within my sweaty little palm, I’m headed up to see Peter Gabrielle at Birmingham’s LG arena…