Which do you prefer, progressive rate springs (i.e. Progressive Suspension Springs) or straight rate springs (i.e. RaceTech) and why?

Personally I prefer straight rate springs. I like knowing that my suspension will compress at an even rate over its length of travel. I don't want my suspension suddenly getting stiffer and stiffer, I want it to be consistent and predictable. I realize that the RaceTech suspension costs more than the Progressive Springs, but I think that it's worth it for the straight rate.

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Here's a question for you then:

Why do all racers use a straight rate suspension? Why do all manufacturers use straight rate suspension?

I mean, I guess for around town riding Progressive suspension might be a decent choice, but for any serious riding in the corners straight rate is a must, I think.

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From www.SonicSprings.com

QuoteStraight-Rate Springs vs. Progressive Rate Springs

Over the last 20 years, one of the biggest changes in the aftermarket motorcycle suspension world has been the virtually complete switch from progressive rate springs to straight rate ones. I think it's safe to say that there's not a single reputable suspension tuner who advocates progressive springs. The question is why? What's the problem with a progressive rate? Why are straight rate springs better?


One of the problems is that bikes, street bikes anyway, just don't have enough travel to take advantage of progressive rates. The soft initial portion gets blown right through, leaving a limited amount of travel for the stiffer portion to deal with. This results in less compliance, less traction and a harsher ride. Another issue is damping; Damping rates, particularly rebound damping, need to be matched to the spring rate. With a progressive (i.e. variable) rate, that's impossible. Damping is always a compromise and a progressive rate just makes the balancing act that much more difficult. Adding to the problem is that modern forks actually have 2 spring mediums, the steel coil and the air trapped inside. The air is intrinsically a highly progressive spring. Adding a progressively wound steel spring to the mix is just making a bad situation worse.

what would be the size to get for the GS from racetech?

Quote from: AlphaFire X5 on April 18, 2006, 02:29:22 PM
Here's a question for you then:

Why do all racers use a straight rate suspension? Why do all manufacturers use straight rate suspension?

I mean, I guess for around town riding Progressive suspension might be a decent choice, but for any serious riding in the corners straight rate is a must, I think.

Sounds like you answered your own question.  Either that or your pissed because you spent more money on an inferior product.   

From all the things I've read, including the website you posted the other day, straight rate sounds like the way to go.  Actually everything I've read bashes progressive rate springs.  Progressive rate springs seem like any easy 'one size fits all' approach to solving the stock suspension.  While I have no experience with it, I would go with straight rate springs and cartridge emulators because it sounds like the proper way to fix our suspension.   

On the other hand, straight rate springs may not be the best idea if you plan on selling your bike.  If I get straight rate springs/spacers/oil for me, a 200 lbs potentially aggressive rider, the suspension would be lousy for a 120lbs sissy girly rider.  Progressives sound more forgiving to different riders and riding styles.

Again, this is just what I've taken from my reading

Quote from: afplayboy18 on April 18, 2006, 02:52:02 PM
what would be the size to get for the GS from racetech?

Check out Racetech's website.  http://www.racetech.com/evalving/menu/searchstreet.asp

Quote from: Jake D on April 18, 2006, 02:55:05 PM

Quote from: AlphaFire X5 on April 18, 2006, 02:29:22 PM
Here's a question for you then:

Why do all racers use a straight rate suspension? Why do all manufacturers use straight rate suspension?

I mean, I guess for around town riding Progressive suspension might be a decent choice, but for any serious riding in the corners straight rate is a must, I think.

Sounds like you answered your own question.  Either that or your pissed because you spent more money on an inferior product.   

Well, considering my straight rates soak up bumps amazingly well, I don't think Progressives would be better at all. Progressives are rated from .51 kg/mm to .8 kg/mm. The stock GS spring is rated at .54 kg, which means that the initial Progressive rating is LESS than the puny stock rating. If you thought the GS went through its suspension travel too quickly, it'll go through the initial progressive rates even faster. Again, noting the article I posted earlier, the amount of suspension travel isn't nearly enough to take advantage of the higher rate in the Progressives. Straight rate matched for your weight is far more beneficial.

Check it out, there's a poll!

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Well, if you give me a few years...I'll have thouroughly put my progressive springs through their paces...and I'll move on to something like Racetech to check it out 

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Quote from: Wrecent_Wryder on April 18, 2006, 05:14:46 PM
Counterpoint- you know what else, besides progressive springs, you don't see on the track? 

Bumps.  No speed bumps, no potholes, no frost-heave buckled pavement, no train tracks, no expansion joints...

It's interesting what goes on out there, but it's far removed from the world most of us ride in...

Not true.  Turn 6 of the racetrack formerly known as Sears Point, now Infineon, has a nasty section of bumps that follow the turn in the middle of the track, if you don't plan you're line right and run wide you're gonna hit these.  Additionally, out of that turn and setting up for turn 7 you'll run into the end of the dragstrip where there is a nice expansion joint, maybe right where your turn-in point could be, furthermore you'll run into the beginning of the drag coming out of turn 11 with another 'spansion joint.  Fun.  Also, Sears is one of the few tracks where the cars run in the same direction as the bikes which really tears up the track and creates those ripples in the pavement, or asphalt, from hard braking, similar to the ones you experience at stoplights.

IT DEPENDS IF YOU WANT THE GOOD STUFF BOLTED ON YOUR BIKE OR THE CHEAP STUFF THAT GETS YOU BY,I DONT WANT JUNK INSTALLED ON MY BIKE.

Quote from: fordtech on April 18, 2006, 09:33:10 PM
IT DEPENDS IF YOU WANT THE GOOD STUFF BOLTED ON YOUR BIKE OR THE CHEAP STUFF THAT GETS YOU BY,I DONT WANT JUNK INSTALLED ON MY BIKE.

That doesn't really answer the question... and tone the caps down, please. You look silly.

Quote from: Wrecent_Wryder on April 18, 2006, 05:29:56 PM

Quote from: AlphaFire X5 on April 18, 2006, 04:11:10 PM

Progressives are rated from .51 kg/mm to .8 kg/mm. The stock GS spring is rated at .54 kg, which means that the initial Progressive rating is LESS than the puny stock rating. If you thought the GS went through its suspension travel too quickly, it'll go through the initial progressive rates even faster. Again, noting the article I posted earlier, the amount of suspension travel isn't nearly enough to take advantage of the higher rate in the Progressives.

Actually, the "initial progressive rates" don't come into play at all, they're taken up by the pre-load, which we control by the length of the spacers.

  Well, this is incorrect.  The preload spacers do not compress the spring at all;  the weight of the bike does that by itself.  The preload spacers are to adjust sag.  The initial progressive rate seems to affect the first inch--or less--of fork travel after sag--just enough to provide a comfortable ride at speed over the typical highway.  The other comments pertaining to problems matching damping or not enough travel for progressive to be practical do not ring true considering that the rear shock uses rising rate linkages and has less travel than the fork and even the best twin-clickers use only 1 damping setting at a time.   A comfortable ride on a racetrack is not a high priority; steering precision is wrt initial turn-in and suspension movement there is a liability under race conditions....so straight rate makes some sense there.   

I forgot to vote.      I should also add that every bike I've owned--including the GS450--has had progressive springs as stock items.  None of these had the fancy damping that you find in modern sportbikes though.  The GS500 uses straight-rate springs but no one seems too excited about that.   

Quote from: Gisser on April 18, 2006, 11:09:52 PM
The GS500 uses straight-rate springs but no one seems too excited about that.   

It's because their spring rate is too low. Straight rate springs matched to your weight and riding style are a FAR better investment than progressive rate springs, IMO.