Too big a sag figure (it drops too much when you get on) and your suspension could bottom out under braking and cornering. Too small a figure (doesn’t drop enough) and it could “top out” under acceleration or over bumps and damage the shock.

The general rule of thumb is that when the rider is riding on a flat and straight surface, the shock compresses one-third of the way through its total travel. That way, when the rider hits a bump, the shock can compress two-thirds of its travel; if the rider goes over a rise in the road, the shock can extend one-third of its travel and the wheel can stay in contact with the road.

Morning Chris, Mick and Larry.

Larry, the Dallas Cowboys want to thank your Lions for doing them a solid yesterday.

 

Stan, the shock can reach its travel limit on the up stoke or rebound also. Hence the need for the sag, to get the piston in its “ center of travel “ so it can work in both directions.

 

Heady discussions here.... could lead to a shocking development!

 

Oh, and Stan, sag also determines the chassis geometry angle. With less shock sag, the rear of the bike will ride higher causing a quicker steering response. The more shock sag, the rear of the bike will ride lower and improve high speed stability. These are General thoughts Stan and you set it up for you and your preferences.

 

Thanks Gents- good info and common sense when you think about it.
Plus, I like the idea of my piston being "centered", allowing me to stroke it in either direction for the best ride, for my partner too .....

 

An inch or so in each direction???

 

If you under set sag to allow for a softer ride, which I take as reducing preload, means you are actually using up more travel when you sit on the bike vs less. So you'll have a softer ride, but bottom out much sooner. Lets say you adjust it to 1/2 the travel of 3 inches. Obviously that leaves you with only 1.5 inches of compression travel. Sure, you also have 1.5 of "extension" travel, but that isn't as helpful when trying to absorb road irregularities.

Biggest issue I have here is the frost heaves and expansion joints. They're like mini speedbumps on the highway. You hit those at 75 MPH and it plays hell on the suspension, either bottoming the shock, or bucking you off the seat because the spring is too stiff to absorb it. It's a very fine line of adjustment to reduce the severity of those hits, and then maintaining an acceptable ride on good roads. That's where more travel really helps. 3 inches isn't enough. Hell.....sometimes 5 inches isn't enough (That's what she said!). But on rough roads, more is better. I ran 13.5s which is the minimum I would do. 14s would be even better.

 

Ya, ......Max !
Hahahaha

 

Good point -
I appreciate all comments on this guys, and the help "thinking it through". Greg, Bob, Chuck, Russ ............. and yes, AL.