stiff rear suspension

[putsy]

Hi all, I installed Progressive series 12 rear shocks on my 1979 GS750L, and went with the heavy duty springs being I weight about 275. I've had them on for a couple of months now and adjusted the preload on all settings and these things are stiff. I've been thinking of removing the new springs and putting the old stock springs on the new shock. Has anyone done this or have some advise wether a good idea or not. Thanks.

 

[waterman]

First off, welcome to the GSR forum.

I too had thought that the HD springs from progressive are a little stiff. I am not far from your weight and thought more would be better. They do work well when using a passenger but for solo, they can be a bit much.

If the stock springs fit, I can't see that they would hurt anything. If they don't fit, you could order some regular capacity springs from progressive. Likewise, other springs may fit the progressive bodies as well.

 

[posplayr]

I dont understand they springs being too stiff, I have ridden Chef's bike which has HD springs and it rides very well and He has 80 lbs on me

I would not go back to OE springs unless you can confirm the sag setup is correct.

 

[UncleMike]

How many miles do you have on them? They'll soften up a bit as the miles pile up.

 

[Guest]

How many miles do you have on them? They'll soften up a bit as the miles pile up.

That's what I was thinking Mike.

 

[ChicagoBob]

I did the same.

I did the same.

I changed back to the stock springs, and got them to fit using a mixture of parts from both sets. Much better ride, with good damping control.

 

[putsy]

Thanks for the welcome waterman, yea I dont understand why they would be so stiff either. I even installed new progressive fork springs to stiffin the front up to match the back. After cutting and trying three differnt size spacers I settled on the 4 inch, which is what progressive called for in the first place. That defenitely helped, I think that both sides are equal to each other were they should be, but still too stiff. For unclemikes question, I have put a little over 3000 miles on these, do you think thats enough to soften up?

 

[UncleMike]

Thanks for the welcome waterman, yea I dont understand why they would be so stiff either. I even installed new progressive fork springs to stiffin the front up to match the back. After cutting and trying three differnt size spacers I settled on the 4 inch, which is what progressive called for in the first place. That defenitely helped, I think that both sides are equal to each other were they should be, but still too stiff. For unclemikes question, I have put a little over 3000 miles on these, do you think thats enough to soften up?

Not really. I'd say they weren't even broken in yet.

 

[Billy Ricks]

Read up on setting up the sag as POS mentioned. Sag is the difference between the suspension fully extended with the wheel off the ground and sitting on the ground with your weight in the seat.

 

[posplayr]

see ohlins sag instructions


http://www.thegsresources.com/_forum/showpost.php?p=994640&postcount=7

 

[putsy]

Thanks guys, I'm going to look into that and see what I can come up with.

 

[putsy]

Ok, I did some reading and measuring on the bike. With the next to the softest setting on the preload for the rear, rider sag is 38mm, static sag is 12mm. For the front I got rider sag 88mm, static sag at 63mm. Correct me if im wrong but that seems to be way high. So do I need to go stiffer to bring that number down or the other way. I had longer spacers in before, but seemed too stiff. Thanks.

 

[posplayr]

Ok, I did some reading and measuring on the bike. With the next to the softest setting on the preload for the rear, rider sag is 38mm, static sag is 12mm. For the front I got rider sag 88mm, static sag at 63mm. Correct me if im wrong but that seems to be way high. So do I need to go stiffer to bring that number down or the other way. I had longer spacers in before, but seemed too stiff. Thanks.

Stiffer reduces the sag.

Static sag is set with the preload.

If rider sag is too much increase spring stiffness.

For the front progressives are nice, or if you cut 10% of the coils off of an OEM spring it will increase stiffness by 10%.

On the rear you already have the stiffest or is that measurement after putting the OEM back on?

 

[putsy]

No the progressive shock and spring are still on the rear of the bike. How much more spacer or piece of spring do you think i'll need for the front?

 

[almarconi]

I have similar setup on my bike and am confused by your measurements. When you are sitting on the bike, the front sag should be about 1.25-1.5 inches. The front spacer I used stuck out of the fork tube about .5 inch before compressing the cap. I used 15w fork oil. The rear has the 105/150 rate springs, I weigh 230 and have them set on the lightest setting. This provides a firm ride but its not harsh. The bike rides like it is on rails.