Thetelescopicmotorcyclefork has been with us for a very long time. Well over a century, in fact. It was 1908whenAlfred Angus Scott fitted one to his groundbreaking two-stroke machines and the design has been developed ever since. It isn’t without its detractors however; expecting a pair of sliding legs to cope with steering and braking is a tall order, and add a constantly changing wheelbase and trail and there must be better ways of going about it?
Throw a sidecar into the equation and we can add side loads too and, if those forks flex, they are going to stick. WhenMr Scott developed his three-wheeled Sociable post-First WorldWar it is noticeable that he was a good enough engineer to realise that the single front wheel needed better location. He gave it conventional rack and pinion steering as used on ‘real’ cars; sadly, he seemed to have used up all his mechanical know-how on the frame and steering, leaving little to consider aesthetics or even fit for purpose. Perhaps inevitably his concept of melding car and sidecar came to very little, only around 200 were ever made.
[https://magarticles.magzter.com/articles/5238/376637/5d9d8bbcc4aa2/1570605929370.jpg]
Modern opinion seems to be that leading link forks are essential for pleasant side caring, with hub centre steering also gaining in popularity. Leading link forks have the ability to separate steering and braking forces while still giving good suspension travel. It is noticeable that the only manufacturer of production outfits, Ural, choose to use them and they are pretty much ‘go anywhere’ machines.
Inmost riders’ view that type of fork’s main attribute is that it can be engineered to reduce fork trail. Less trail equals less effort!
Indeed, in the classic era, some of the more enlightened manufacturers offered ways of reducing trail. Various ways were tried including offset yokes, lower castings with a different axle mounting or, in the case of Vincent, adjustment via eccentrics to achieve the same end result. With even oldermachines it was possible to change the length of the lower fork links to reduce trail. When girders were modified as such it was not unusual to see an extra dorsal tube incorporated to add some much-needed stiffness to combat the side loads generated by the chair.
[https://magarticles.magzter.com/articles/5238/376637/5d9d8bbcc4aa2/1570605929378.jpg]
My own BSA A10 steered quite well with the standard setup, although I suspect that BSA compromised on the fork geometry knowing that many ...
Throw a sidecar into the equation and we can add side loads too and, if those forks flex, they are going to stick. WhenMr Scott developed his three-wheeled Sociable post-First WorldWar it is noticeable that he was a good enough engineer to realise that the single front wheel needed better location. He gave it conventional rack and pinion steering as used on ‘real’ cars; sadly, he seemed to have used up all his mechanical know-how on the frame and steering, leaving little to consider aesthetics or even fit for purpose. Perhaps inevitably his concept of melding car and sidecar came to very little, only around 200 were ever made.
[https://magarticles.magzter.com/articles/5238/376637/5d9d8bbcc4aa2/1570605929370.jpg]
Modern opinion seems to be that leading link forks are essential for pleasant side caring, with hub centre steering also gaining in popularity. Leading link forks have the ability to separate steering and braking forces while still giving good suspension travel. It is noticeable that the only manufacturer of production outfits, Ural, choose to use them and they are pretty much ‘go anywhere’ machines.
Inmost riders’ view that type of fork’s main attribute is that it can be engineered to reduce fork trail. Less trail equals less effort!
Indeed, in the classic era, some of the more enlightened manufacturers offered ways of reducing trail. Various ways were tried including offset yokes, lower castings with a different axle mounting or, in the case of Vincent, adjustment via eccentrics to achieve the same end result. With even oldermachines it was possible to change the length of the lower fork links to reduce trail. When girders were modified as such it was not unusual to see an extra dorsal tube incorporated to add some much-needed stiffness to combat the side loads generated by the chair.
[https://magarticles.magzter.com/articles/5238/376637/5d9d8bbcc4aa2/1570605929378.jpg]
My own BSA A10 steered quite well with the standard setup, although I suspect that BSA compromised on the fork geometry knowing that many ...
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Old Bike Mart (Digital) - 1 Issue, October 2019