BRITISH EXPERIENCE MEETS AMERICAN MOTIVATION

Ever wondered how to design a new motorcycle from scratch?

Well a book in our library provides an outline, without covering all the theories, calculations etc.

Book M-127 The Victory Motorcycle.

( The Making of a New American Motorcycle)

US company Polaris is a leading maker of snowmobiles, ATVs, watercraft and golf carts (some with Polaris engines) and their 1993 research showed a market opportunity for American motorcycle cruisers, as only Harley Davidson and some small-volume builders were serving this market. This research dictated the bikes must  have U.S.-built engines and major components.

In 1996 Polaris put together a team of designers, including a key engineer, Scotsman Geoff Burgess, who was with the Norton-Villiers-Triumph group( and the Triumph-BSA research centre) in the 1960s before emigrating to North America.

The Victory team benchmarked many motorcycle makes, with Burgess insisting on British-bike handling quality as top priority, (not a traditional cruiser trait) e.g. the designed and developed chassis prototypes used slave-engines, then the in-house engine was designed to fit.

Other Burgess British-bike influence resulted in………

· A Vincent –type triangulated rear fork with under -seat suspension unit (also copied by Yamaha in the 1980s)

· The Norton Manx practice of aligning the crankshaft (engine positioning) with the front and rear axle centres was adopted.

· The Vincent 50° cylinder inclusive angle to suit the available frame space (55° initially).

· Engine solid mounted, with balance shaft…up to then Harley had spent 15 years trying for satisfactory rubber mounting ( but giving dubious handling).

· Class forks (Marzocchi) and brake components  (Brembo).

For the in-house designed and built engine, Polaris declined design input from UK.Lotus and Coswirth and instead used UK independent consultant Mike Mills¾who worked with Burgess in the Norton-Triumph days.

The first Victory engine ran in late 1996 then many, many dyno and road hours testing in prototype and pre-production bikes led to production model release mid 1997. One change was to the balance shaft, it worked too well and was modified to give some big-twin vibes!

Book critic verdict…………….a good read.

Jack Youdan.