Thread: How does this work?

Originally Posted by Tusker

"REAR SHOCK MOUNT 3 POSITION

This shock mount still uses our 11 inch travel (challenge) PIN/PIN fixing and allows

you to mount the shock absorber in 3 different positions , 1st hole is a stiffer ride

for road handling , 2nd hole slightly softer ride and 3rd hole for more articulation..."


Pics at

Shock Mount


How can the ride change if the top mount moves? Isn't a shock uniform throught its travel?

Brilliant idea if it works though.

Regards
Max P

Hi Max,
If the shock is inline with the axle travel the shock and axle travel and velocity will be the same. If the shock is 90 deg to the axle travel then it won't move as the axle moves and won't give any damping. As you move it between the two extremes the ratio of axle to shock travel and velocity will change.

And yes it does look neat, as long as you need least damping and max travel at the same time.

Tony

I think it is probably to do with the amount of force being transmitted through the shockie at each different position.

If the shockies were vertical virtually ALL the force would push the shockie up and it would give the full damping effect and thus appear firmer.

By angling the shockie more and more, less force is being distributed to the shockie and it appears to be softer.

Aren't pin to pin shocks cheaper than eye to pin shocks?

Originally Posted by Tusker

"REAR SHOCK MOUNT 3 POSITION

This shock mount still uses our 11 inch travel (challenge) PIN/PIN fixing and allows

you to mount the shock absorber in 3 different positions , 1st hole is a stiffer ride

for road handling , 2nd hole slightly softer ride and 3rd hole for more articulation..."


Pics at

Shock Mount


How can the ride change if the top mount moves? Isn't a shock uniform throught its travel?

Brilliant idea if it works though.

Regards
Max P

The closer a shock is to vertical, the stiffer the ride, and the shorter the travel, as the shock moves the same distance as the axle (at the attachment point).

If you incline the shock away from vertical, the shock will compress/extend less than the axle for any given amount of travel, meaning that (a) you would need a stiffer shock to provide the same amount of damping, and (b) you can get more axle travel for a given shock length.

All of the above ignores the fact that axles don't move straight up/down... however that should make little difference.


EDIT. Depending on the link geometry, you can also change the way the shock works by changing the angle.
e.g., my bike frame has 3 positions at each end of the shock mount.

by changing between them you can either get suspension with a linear rate, rising (progressive) rate, or decreasing rate.

Of course in this case you are changing the spring position as well, in a landie you would just be changing the damping rate.

The different positions look as if they would change the angle relatively little - I wonder if you can tell the difference?

John

Thanks all.

Didn't occur to me that's all it was.

And, looking at those pics, the top bush doesn't look very happy does it.

Regards
Max P

Looks a great innovative idea to me. At the front hole it should give extra travel as the axle swings forward.

I may be tempted to buy some.

If it doesn't break shock shafts with those stiff poly bushes then it would be even better with rubber ones.
Regards Philip A

If the rear shockie was close to vertical, small angle changes would not make very much difference to the dampening. But because the rear shockie is already laid forward a fair bit, the same angle changes will affect the dampening more.