2017 ES Suspension Disapointment

[raYzerman]

Suspension discussions get complicated, not many understand it, all you can do is do your own research. Several books available also.

Rule #1 of suspension, the spring has to support your weight, damping controls the rate at which the spring compresses and rebounds.

On both the ES and A, it's undersprung. ES is 685, A is ~650 (formula for 2 springs in series), both designed for the 150 lb. guys, maybe less depending on whose spring calculator you're using. A 200 lb. rider needs ~850-ish, which jives with my personal experience with an aftermarket shock. Playing with damping can compensate to some degree, but if you have to add too much..... we're back to the spring issue needing some kind of fix/replace.

How to envision it, all springs are preloaded or compressed a bit as installed. Add a lot of preload to a weak spring or add little or none additional to the proper spring... which do you think rides more plush/has more travel available?
On the damping side, one must add stiffer damping to keep the weak spring from compressing/rebounding or pogo-ing.

A shim will simply add preload to the spring, you are attempting to compensate for its low spring rate by squeezing it together. Works to a point. Big question is how much can I preload a 685 lb. spring to make it feel like 800.... hard to find a calculator for that info, but I'll bet Cogent or Ohlins know from their shock dyno testing... they are all going to recommend you get the right spring.
In this case, I would try a 1/4" shim (6mm), that is significant. It will lessen the need for damping.

ES has good fork springs (1.0) for a 200 lb rider. Rear doesn't. Damping is by Yamaha's formula, not separable by compression or rebound, or front to rear, it all moves at once. It's also the only thing you can adjust while the bike is moving.

[SkooterG]

Add a lot of preload to a weak spring or add little or none additional to the proper spring... which do you think rides more plush/has more travel available?

So what is your answer to this? Because I have a feeling mine would be different.......

[raYzerman]

I thought it was obvious...... need the proper spring.