The Classic MotorCycle – September 2019

If longerflattened length required, workalong in stages and for large diameter tubeflattened in

stages, working along the length for each stage.Tedious–but it works.

Once happywithflattened work, measure, centre punch and drill

required hole or holes.Iuse athe bench drill for this and startby

makingasmall diameter guide hole withahard tip to prevent drill

wander,then workupdrill sizes to the^5 ⁄ 16 inch example here, or

whatever is required. Ifabench drill is unavailable, good results are

achievable withahand drill.File, linish or grind end to shape required

and complete dressing up.

This only works with small diameter (up to^5 ⁄ 8 inch/15mm) thickwall tube.
Forlarger sizes,filling with appropriate sand helps–dried seashore
sand isfine and dried silver sand works too.We’lllook at this technique

after my next trip to SunnyHunny(Hunstanton). It is of course possible

to bend steel pipe using plumbers’ type pipe bendersbut in my hands

these extrude andwaist the pipe, which looks obvious and unsightly.

Using either an oxyacetylene or butane torch withfineflame, heat the

tube radially in ¼in (7mm) lengths and bend in tinystages. The colder

regions either side of the cherry red ring created supportthe wall of

the heated area to prevent collapse while proceeding with the bending

exercise.Work along the piece in stages and takemore than one pass

along the worktocomplete the task.

This mayseem an amateur,tedious process. However,all bends

on the carrier of our (mywife’s) 1912 499 Curry-JAP were carried

out in ½in thickwall mild steel tube. Assemblywascompleted with

lugs machined on the lathe, with brazing to unite the lot, then lots of

dressing up withfiles and strips of emerycloth. Without intentionby us,

the machinewasawarded amajor concourstrophyin2018 (red faces

on our partaswedidn’tenter the concourspartoft he event) so the

carrier must have passed muster with the judges!

The following approach is intended for tubular

carriers, mudguard stays and the like, but for

safety reasons cannot be recommended for

frames or girder front forks. Unfortunately our

cupboard of bent, mangled carriersisbare,

leading to the contrived damage to newlength of

tube illustrated. But it serves to demonstrate the

type of repairscarried outby us in the past.

willingly paytheir share(in fact theycan’t

gettheir moneyout quickenough!) then

theycangetmetodoall thebrazing,welding,

bending, buttheydonowsweatout their

ownfasteners andbearings,soIguessthat’s

aformofprogress.

Thefollowing waseffectedwith items

from this motleyselection ofequipmentand

if youlikethe idea,wewill include morein

futurefeatures.

THE CLASSICMOTORCYCLE|SEPTEMBER 2019 95

Classics

ife