By David Porter, Customer and Technical Support at The Bonneville Shop
Table of Contents
Having trouble fitting Triumph parts to your vintage bike?
This interesting Triumph Service Bulletin, issued on 11/9/1973, seems to confirm what many of us have known all along- sometimes you have to massage parts to make them fit correctly, or slightly modify them to improve fitment. Pattern parts originate from all over the globe and are manufactured to varying tolerances. We find that exhaust systems, seats, fenders, sheet metal components, wiring harnesses, and many other parts require “fettling”, as the Brits would say.
“We find that exhaust systems, seats, fenders, sheet metal components, wiring harnesses, and many other parts require “fettling”, as the Brits would say.”
What is Fettling?
Fettling is the art of cutting, grinding, bending, filing, and adjusting a part or assembly to correct the fitment. This Service Bulletin proves that this fine tradition has been practiced for a long time, even with new and unused factory parts on our beloved British Iron.
Triumph Service Bulletin (Twin) 12/73
The factory 83-1358 and 82-8042 side cover/tool box was known to have a sharp edged corner at the hinge cutaway that was perilously close to the wiring harness. Fitting Triumph parts like the side cover can require some extra work. Dealers were instructed to remove the sharp corner by means of grinding or cutting with “dykes”, then filing smooth the affected area, obviating the chance of chafing the wiring.
This type of fettling was done in the service shop of the authorized dealer on a genuine factory part installed on a new motorcycle. It is not unreasonable to expect to have to make slight adjustments on reproduction parts when fitting Triumph parts. Fortunately, the reproduction side covers we offer are pre-fettled with respect to the hard corner edge on the seat hinge cutaway.
TRIUMPH SERVICE BULLETIN
Number: (Twin) 12/73
Subject: Side Panel Modification
Model: T100
Date: 11/9/73
LEFT PANEL AND TOOL BOX
The wire harness on T100R’s is routed under the top of the left side panel very near a sharp corner. This sharp corner will chafe the wiring causing an open wire or short in the harness.
REMOVE SHARP CORNER
By means of grinding or cutting with dykes, the sharp corner should be removed, as shown in Fig. 1. Remove all burrs and sharp edges from this area before reinstalling the panel.