Spring calculation help for a loveable fat man

[ducpainter]

Mine has Showas.

I've never seen an early bike with the Marzocchis.

I use different numbers because I have a different valve.

ATF is hydraulic oil. I would use the 7.5 weight with stock valves.

[Michael]

Mine has Showas.

I've never seen an early bike with the Marzocchis.

I use different numbers because I have a different valve.

ATF is hydraulic oil. I would use the 7.5 weight with stock valves.

Thanks DucPainter. I'm glad guys like you are around.

So, 7.5 weight with stock valves? What about the weight issue -- I mean, my weight issue -- I'm a bit heavier than the average rider, so would a heavier/thicker oil be necessary? Or does that concern only apply to springs?

[ducpainter]

Thanks DucPainter. I'm glad guys like you are around.

So, 7.5 weight with stock valves? What about the weight issue -- I mean, my weight issue -- I'm a bit heavier than the average rider, so would a heavier/thicker oil be necessary? Or does that concern only apply to springs?

Exactly...

The spring supports your weight.

The compression damping slows the spring as it compresses to avoid bottoming and the rebound slows the spring as it uncoils to avoid the pogo stick effect.

Since the stock valve has very small holes thick oil gives too harsh a ride over things like manholes or expansion joints on bridges.

Damping and spring weight are related. A change in springs normally requires something be done with damping because you're trying to control the spring. Since the stock damping so is stiff I'd try lightening the oil. It will make the front more supple.

There is some trial and error.

The experts just have enough of a data base from all their experimenting to know what scenario works best in a given situation.