08-25-2020, 01:18 PM
Did Horstman make some RevGrips with the spider legs facing forward?? See 3 pics.
We run mostly RevGrips on our McCullochs (tapered shaft). Most have inboard sprockets. In all cases, the four "arms" on the hub (aka "spider") point in the direction opposite the engine rotation. Makes sense... as RPM increases, and the shoes contact the drum, the back-sloped "arms" acts like ramps, helping the shoes to "dig into" the clutch drum, thereby keeping them from burning up.
(Same idea as the familiar leading shoe in a drum brake setup.)
HOWEVER, I recently picked up a RevGrip that has the arms pointed forward, i.e., in the same direction as the engine rotation.
What the heck am I missing?
The spider also has some peculiar geometry on its outboard edge, which I believe is for starting off of a pulley on the end of the crank. (I didn't get any pulley or nut with this clutch.)
We run mostly RevGrips on our McCullochs (tapered shaft). Most have inboard sprockets. In all cases, the four "arms" on the hub (aka "spider") point in the direction opposite the engine rotation. Makes sense... as RPM increases, and the shoes contact the drum, the back-sloped "arms" acts like ramps, helping the shoes to "dig into" the clutch drum, thereby keeping them from burning up.
(Same idea as the familiar leading shoe in a drum brake setup.)
HOWEVER, I recently picked up a RevGrip that has the arms pointed forward, i.e., in the same direction as the engine rotation.
What the heck am I missing?
The spider also has some peculiar geometry on its outboard edge, which I believe is for starting off of a pulley on the end of the crank. (I didn't get any pulley or nut with this clutch.)