Freddy
Active member
Given that THAT bolt's purpose to provide the clamping force between the shaft flange and the sprocket (not just stop it falling off) so that the spline does not transmit rotary movement, as stated, then if there is no movement between spline and hub, due to adequate clamping force, surely neither steel or aluminium would fail as there would be no relative movement. I agree that an ali pulley should have a steel hub for longevity but a slightly loose steel hub has a short life, as we can see.
As BRP concedes, there is a settling in period after which the bolt must be retorqued - perhaps after the damage has started. Any relative movement will damage the pulley and/or spline I believe. Let's hope they all get checked then rechecked periodically and maybe fit a new bolt every second or third retorque.
A slightly loose bolt combined with the original belt tension equates to short like expectancy and probable bolt breakage, which we have seen. Lower belt tension with slightly loose bolt equates to slightly longer time to failure, I believe.
As BRP concedes, there is a settling in period after which the bolt must be retorqued - perhaps after the damage has started. Any relative movement will damage the pulley and/or spline I believe. Let's hope they all get checked then rechecked periodically and maybe fit a new bolt every second or third retorque.
A slightly loose bolt combined with the original belt tension equates to short like expectancy and probable bolt breakage, which we have seen. Lower belt tension with slightly loose bolt equates to slightly longer time to failure, I believe.