Sprocket selection and the effect on the clutch ?

[TrackTen]

I have read ( somewhere ) that the selections of sprockets will have an effect on the clutch - I assume slipping ?

I understand how a high overall ratio can affect the clutch but can someone explain how the primary ratio selection can effect the clutch please

[Warkton Tornado No.1]

A desired overall top gear ratio can be met with various combinations of gearboxes & primary drives as you are no doubt aware. For example, if a 4.44 was desired, two ways in which this can be achieved (Reference with acknowledgement: S&S Gear Ratio Table)

TV200 x 15 x 46
Li150 x 18 x 47

As a consequence, the torque load on the clutch is higher with the TV200 as opposed to the Li150.

Primarily, this was an issue when the limitation was the standard four plate clutch of yesteryear.

There is , however, another ‘trade off’ nowadays, because, with the advent of usable five/six plate clutches & more powerful engines, the gearbox can then become the weak link, particularly the vulnerable first & second gears.

I had been meaning to ask how the ‘Production Class’ gearboxes (limited to GP125/200 I believe) were coping because the top bikes are ‘up there’ with the ‘Group Four Class’ (with one notable exception) so feedback from anybody that can comment would be great to see.