Kicking a Dead Horse. Progressive or Sonic?

[pliskin]

I'm going to upgrade my springs GS F. I have a R6 rear on the way and I need to decide on what front springs to go with.

From what I understand progressives by Progressive only come in one spring rate....no spring rate choice.
Sonic gives you a choice based on the total weight they will carry (at 215lbs plus 430lbs for the bike they rate me at .85/.90)

So, in your opinion which would cure the front end diving better? I would think Progressives would flatten out hard braking better due to the progressive rate. Am I correct Here? One thing that worries me a little is the F is a little heavier in the front and neither brands list the GS500F as a choice. Only the 500E. So maybe the Sonic is better on the F due to the fact I can go with a little heavier spring.

What do you bigger guys use on your 500F?

[Formori]

I personally haven't changed out my springs, I've got a '05 GS500 F, but the difference between the faired and unfaired bikes is only about 30lbs, so not a big difference at all.

Personally, I think the progressive springs would be much better than a heavier Sonic spring, since the sonic would be stiffer all the way through the range and make for a much rougher ride, where the progressive's would balance better and still stiffen up on a hard stop.

Just my 2 cents.

[jestercinti]

I have heard that unless you are on the track or doing some aggressive riding, that the difference in normal street riding is not very much for normal everyday riding.

[burning1]

Personally, I think the progressive springs would be much better than a heavier Sonic spring, since the sonic would be stiffer all the way through the range and make for a much rougher ride, where the progressive's would balance better and still stiffen up on a hard stop.

Intuitively, that seems correct. In practice, straight rate springs tend to work better.

Progressive springs have the issue that they tend to be too soft at the top of travel, which makes it difficult to get your preload correct, and causes you to blow through travel too quickly. Beyond that, our forks are, by their very nature, progressive. There is a volume of air trapped in the forks, and as the forks compress, that air creates a progressively stronger spring effect. Tuning the oil level is critical for suspension performance at the absolute end of range.

I'd strongly suggest running Sonic springs. The owner of the company is a great guy, and shows up here occasionally to offer advise.

[fraze11]

I'm not dismissing Burnings post, he's right   I'm just sharing with you that I have progressives (w/15wt oil) in my 09F and I too have an R6 rear shock (its off an 09).  For me its been an excellent experience, my ride and handling has increased ten fold.  And yes, the nose dive front braking issue will be gone!  Im 5'9 170lbs and those 2 upgrgrades are without question the best money I spent on the bike...period.  I'd argue that for street use you'd not see a difference in the 2 but I'm not a track racer so I can't say that with certainty.  I doubt you'd regret Progressives but its your decision and either way you'll thank yourself everytime you go for a ride 

[burning1]

Straight rate or progressive, either direction you go, you'll be way better off than stock.

Suspension tuning is very valuable for street comfort and safety. I tend to talk from a track perspective, but getting the suspension right really helps make the bike feel solid and confident going into the corners, and can really improve safety when you're riding on rough roads.

A well tuned suspension will be firm under braking, but compliant over bumps. Getting it there takes work.

[adidasguy]

#5126

Burning is right that the air column compressing is essentially a progressive "air spring".

I have 0.85's in 3 bikes. Progressives in another. Jumping from bike to bike, for street riding, I can't tell any difference.
"Progressive" I feel is a buzz-word and doesn't matter for street riders.