GStwin.com GS500 Message Forum

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.

h7

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.

[78

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.   :icon_lol:

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.   :icon_lol:

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!

[h

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  :laugh:

[9

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.

:icon_rolleyes:  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.   :cheers:

I forgot to vote.   :icon_rolleyes:   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.  :icon_razz: 

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.  :icon_razz: 

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.

My question regards relying mostly on manucturers information:

Why would anyone expect a company that makes and sells any product, springs included, to say that a competitors (Progressive) is better for any application?

As to which I would (and did) go with? Progressive.

For others, I believe it depends on the primary use of the bike:

primarily: track - highly aggressive - other specialized app type riding = straight rate tuned to the rider,

primarily: beginner - normal street type riding - play in the twistys once in a while - devoloping your skills type stuff = progressive.

Remembering that the GS500 is aimed mainly at the entry level / beginner / street type rider, by the time most people begin to approach the point that they can take advantage of the difference they either get a different more suitable bike, or stay with the GS just because they like it. (And most that move on, do so for other reasons than they have come anywhere close to the limits of the GS500)

But what do I know?  :dunno_white: (57 yrs old and I have only been riding a motorcycle for a year.)  :dunno_white:

[k

[4

Quote from: Wrecent_Wryder on April 19, 2006, 05:35:33 AM
I think we've all gotten your position on it. I'm keeping an open mind, I'm just not persuaded yet.

However, just repeatedly stating something as fact doesn't make it true, and doesn't really add credence to the position advocated.

I feel I've backed up my position fairly well with the evidence I've put forth.

Quote from: Wrecent_Wryder on April 19, 2006, 05:25:15 AM
Ok, maybe I'm misunderstanding something- it happens- but the springs are compressed when you put them in the tubes (screw the caps in place), no? The longer the spacer, the more they're compressed when you put them in the tubes. That is pre-load as far as the springs are concerned, even if it's not by your definition- works exactly the same as the cam on the rear shock. So- the INITIAL rate of the springs (for the first mm of travel) IN USE is higher than the spring tested on it's own, and depends on the length of the spacer. So long as there's some compression of the spring in the tube, the initial rate in use will never be as low as .51 kg/mm.

It's just a matter of using some visualization and it's good that you bring-up the rear shock preload adjustment for comparison because everything's out in the open where you can see it.  You can measure the length of the spring on the shock at its lowest setting (with a rider aboard).  Now crank-up the preload to the "firmest" :icon_rolleyes: setting (#4?) and  remeasure the spring in similar fashion.  There will be no change....there will be no additional compression of the spring....no extra rise in rate to overcome.  The only difference will be a gain in suspension travel and a gain in seat height.  It's all visualization; there is no actual preload to overcome if the suspension is already sagging.   :thumb:   

Quote

Hey Alpha...  How long did you ride your GS with progressive springs?

And... How do each (Higher Rate) Straight and Progressive handle in the rain?

Quote from: RVertigo on April 19, 2006, 03:45:27 PM
Hey Alpha...  How long did you ride your GS with progressive springs?

And... How do each (Higher Rate) Straight and Progressive handle in the rain?

I didn't even bother with progressives, which I guess makes my comparissons based solely on what others who HAVE tried both have to say. Pretty much anyone who does agressive riding, track days, and the whatnot, say straight is the way to go without question.

I just want to stop bottoming out my forks whenever I quick stop or hit a bump...  You should hear the noise when I'm stopping AND hit a bump. :o

Quote from: RVertigo on April 19, 2006, 03:56:41 PM
I just want to stop bottoming out my forks whenever I quick stop or hit a bump...  You should hear the noise when I'm stopping AND hit a bump. :o

I could bottom the forks just sitting there and pushing down on the forks. You're ~185, right? Your reccomended spring rate is .805. The progressives have .51 to .8 spring rates, so your "reccomended" rate would be at the end of the travel of the progressive, which typically can't be reached due to the limitations of suspension travel.

The Progressives, for me, would push the front tire out from under me, when riding in the rain, they would become too stiff (suggested spring rate for me is .715kg/mm).  The .51kg/mm coils are used up quickly both in preload/sag and while braking; there are only about 3 inches of this spring rate, which being at the tightly wound end, quickly become a solid spacer when compressed, and then you're on the .8kg/mm spring rate of the rest of the spring.  I found this unsatisfactory, and have since gone back to the stock straight rate springs (with added preload) which are a little soft for me, but suit my rain-riding style nicely.

Quote from: scratch on April 19, 2006, 04:55:07 PM
The Progressives, for me, would push the front tire out from under me, when riding in the rain, they would become too stiff (suggested spring rate for me is .715kg/mm).  The .51kg/mm coils are used up quickly both in preload/sag and while braking; there are only about 3 inches of this spring rate, which being at the tightly wound end, quickly become a solid spacer when compressed, and then you're on the .8kg/mm spring rate of the rest of the spring.  I found this unsatisfactory, and have since gone back to the stock straight rate springs (with added preload) which are a little soft for me, but suit my rain-riding style nicely.

Bingo. Since you ride in the rain so much, the softer spring rate for you is much better (straight rate matched for your weight and riding style) than the progressive rate springs. It would be MORE ideal if you could get, say, a .6 kg/mm straight rate spring.

For me, I ride in very hot, very dry weather for the most of the time. My riding style is also fairly agressive at times, which means the increased spring rate is more ideal for me.

Quote from: AlphaFire X5 on April 19, 2006, 04:12:56 PM

I could bottom the forks just sitting there and pushing down on the forks. You're ~185, right? Your reccomended spring rate is .805. The progressives have .51 to .8 spring rates, so your "reccomended" rate would be at the end of the travel of the progressive, which typically can't be reached due to the limitations of suspension travel.

I weight 185 and have no problem with street riding on the Progressive Suspension springs that were recommended left and right on this board until recently.  I've not run into the issues that Scratch describes either, but I outweigh him by quite a bit which likely explains the difference.  Since installing the progressives and spacers I never run out of fork travel (a very common occurrence on the stock springs) and the bike handles very predictably, even riding two up with my wife on board pushing the bike's load over 300lbs.

Yes, if you're riding track days frequently or spend most of your time railing corners in the twisties, I'd say spend the extra cash on the racetech springs and emulators, but the progressive springs do just fine for street riding with occasional agressive riding.  I'd go so far as to say that 90% of riders out there don't have the skills to take advantage of the improvements offered by straight rate springs over progressive rate springs, not including the junk springs that come on the GS stock.

What about instaling larger spacers on original springs. I know this is very cheap mod compared to replacement springs, but maybe anyone can give their opinion. Won't the springs bottom out themselves?

Like zis?: http://www.gstwin.com/making_fork_spacers.htm

While it does compress the springs more, I don't think you'll bottom out the springs before the forks do; I certainly haven't experienced that, even under maximum braking.

It feels like springtime with all this talk im hearing,but seriouly sounds like good points on both sides,i guess it al depends on  what you want your bike to ride like,and what kind of riding you do.

What are peoples opinion about just adding spacers to the stock springs?

Does it stiffen up the front end nicely. I'm only just starting to notice how soft the front end is on this bike when stock.

Quote from: galahs on April 24, 2006, 08:53:26 AM
What are peoples opinion about just adding spacers to the stock springs?

Does it stiffen up the front end nicely. I'm only just starting to notice how soft the front end is on this bike when stock.

From what I've read, it works better if you're on a serious budget, but you're better off with new springs. 

Quote from: galahs on April 24, 2006, 08:53:26 AM
What are peoples opinion about just adding spacers to the stock springs?

Does it stiffen up the front end nicely. I'm only just starting to notice how soft the front end is on this bike when stock.

The springs still have the same spring rate, so it'll still be soft in the sense of compressing the springs (will take the same amount of force as before).

It sucks being in Australia some times. So much harder to get parts for the GS500.

I asked on the availability of shims for the valves = 2- 4 weeks

I asked for an oil filter O-ring = 3 weeks

Do they supply any stiffer springs that will fit = I'll get back to you shortly........ Nope!

I found this good read with pictures on replacing your fork springs

http://www.sportbikes.com/wwwthreads/showflat.php/Cat/0/Number/940631/an/0/page/0

shame we couldn't add it to Alpha's awsome FAQ

Quote from: galahs on April 25, 2006, 07:04:30 AM
I found this good read with pictures on replacing your fork springs

http://www.sportbikes.com/wwwthreads/showflat.php/Cat/0/Number/940631/an/0/page/0

shame we couldn't add it to Alpha's awsome FAQ

Pablo already has a "Lazy Man's Install" for progressive springs here: http://pantablo500.tripod.com/id2.html

The write up I did is a more comprehensive change including your fork oil in order to get the correct damping rate too.

I agree, yours was the bomb  :2guns: :thumb:

just his had some pictures.

I like pictures  :icon_lol:

Quote from: galahs on April 26, 2006, 09:16:59 AM
I agree, yours was the bomb  :2guns: :thumb:

just his had some pictures.

I like pictures  :icon_lol:

Yeah yeah. I'll put pictures of all the bolts and stuff you need to loosen and whatnot later.