Do I have progressive spings already?

[Guest]

I'm tackling the forks while I wait for my frame title to show up (don't want to invest the time until I'm sure I can register it.....) and I pleased to see progressive springs come out of the forks... I think.

The bike is an '83 GS750ES and the springs that came out clearly have tighter coils at the top than the bottom... were the OE springs constant for the entire length or did I do the happy dance for nothing?

Thanks!
/\/\ac

[jonr]

Mac,

I believe that when I installed my Progressive fork springs that not only were they tighter at one end, but I had two sets of springs for each fork. One was about 20-24" long and the other about 6".

They may indeed be progressively wound, but not necessarily "Progressive."

J

[Macmatic]

jonr,

Thanks for the info. The diagram in the factory manual shows the stock springs as having a consistant distance between coils so I'm guessing I have some sort of aftermarket... hooray!

Thanks again.
/\/\ac

[mark m]

Thanks for the info. The diagram in the factory manual shows the stock springs as having a consistant distance between coils so I'm guessing I have some sort of aftermarket...

Don't get too happy yet, my 1100 came with progressively wound OEM springs and I would bet yours is the same. If you want to know for sure you need to calculate the spring rate, since the stock rate is woefully soft and any aftemarket ones will be much stiffer. I can run the numbers for you if you want, I need the spring OD, wire diameter and number of coils in the spring to give you a number.

When reinstalling them, make sure the tighter wound end goes up in the forks.

Mark

[Macmatic]

Thanks Mark!

I'm out of town until the end of the week but I'll be taking you up on that when I get home.

In the meantime I'll be wearing out my "refresh" button while wathing my auctions come down to the wire. 8O

/\/\ac

[HiSPL]

Hey Mark (or anybody)

Why in the world would it matter which end is up on Progressively wound springs? I mean wouldn't it take the same force to compress whether it was up or down?


Jus' wondrin.....

[mark m]

Why in the world would it matter which end is up on Progressively wound springs?

Because the tighter wound end is heavier and putting it at the top reduces the unsprung weight a bit. It's not a big difference, especially on our older beasts, but it is free and every little bit helps.

Mark

[IanFrancisco]

[quote="mark m"]

When reinstalling them, make sure the tighter wound end goes up in the forks.

Mark

I emailed Progressive Suspension because I had heard conflicting stories about which way to install the springs. The tech who replied said it didn't matter but the springs would be quieter if installed with the tight end down. The Progressive brand springs are quite a bit noisier than the OEM but who cares? They work great and at 60mph the wind almost drowns out my OE exhaust and I can't hear the forks doing anything. My OE springs were also progressively wound but too soft anyway.

[Jethro]

Noisy springs? Man, I've never heard my Progressive springs.

Also, yes, the stock springs are wound tighter at one end, at least on my 1100. The real Progressives must have a different spring rate?

[Billy Ricks]

If you had Progressives and they were installed properly you would have PVC spacers sitting on top of the springs.

[Macmatic]

If you had Progressives and they were installed properly you would have PVC spacers sitting on top of the springs.

Thanks for pooping on my parade Billy.

No spacers...prolly not progressive. I guess I'll run what I've got until I get a few miles under me.

/\/\ac

[IanFrancisco]

My bike has some aftermarket fork caps with the air valves. When I went to install the Progressive springs, I had a heck of time trying to install the included PVC spacers and ended up leaving them off. I think those end caps stick down farther than the stock ones creating a little preload on their own. The new springs were stiffer and plusher than stock at the same time without any air. Adding 8.5 lbs. to each side gave me even a little more preload and the forks are now working great. I used Harley Type E fork oil for Showa forks. $4 a pint and the shop was 10 miles closer than the nearest Jap shop which is pricey anyway. The Harley oil wasn't marked with an SAE rating but looks to be about 10 or 15 weight. I've heard that using PVC for spacers is not the best. Certain types of PVC supposedly deteriorate and break up. BTW, there were no spacers on the stock setup. If anything, not using the spacers gives me a little more travel, lowers the front end a bit and quickens the steering. Combined with cranking the stock rear shocks up to their firmest and tallest setting, this 400lb bike now feels like it steers as quick as a bicycle.