Progressive fork spring install questions

I am about ready to install the fork springs on my 1982 Seca 650. The install instructions had included a note that there needed to be a 1.5" spacer installed. My main question is does this spacer go on top or bottom of the spring or does it matter, also what size diameter should I use. I have access to either aluminum or PCV pipe, just need to know which size. So any good suggestion would be appreciated. While I am installing the springs, I will also be replacing the fork seals, and replacing the oil. cruzerjd

 

pm'ed u

 

It goes on top - I used pvc conduit for mine, with a large metal washer at each end to avoid any deformation of the pvc.

Size - get whatever fits inside the fork tube.

Oh - and on my bike I found that the 1.5" wasn't nearly enough - I ended up with the spacer being around 4" or so. The recommendation I went with was that the top of the spacer should be close to the top of the tube when at full extension.

 

Thanks all, Altus, I wonder if the Maxim and the Seca might have 2 different lengths? Will definately check on it though. cruzerjd

 

I just bought progressive springs and they are about an inch shorter than the originals... Is this normal?

Cheers

 

I guess it depends on the bike. I put Progressive springs in my forks and they were longer than the originals. I had to cut down the factory spacer to fit them in, using Progressive's instructions. I simply cut the metal tubes with a pipe cutter, worked perfectly.

 

No.
If anything ... they should be AS LONG or just slightly longer than the Stock ones.

(Assuming you had Stock Springs and not somebody's mistake in there.)

 

Cheers... Back to the bike shop they go

 

My progressives were also significantly shorter than the stock springs -- but I double checked and they are correct for the bike. Just used the longer spacer as I mentioned. Been in there a good 5 years now - still wonderful.

 

I was actually contemplating doing that because I got the last set in stock so it could be weeks before they get more

 

This is the thread I've been looking for...

I just installed new progressive springs...and I followed the instructions very carefully. Maybe too carefully.

I made a 1.5 inch spacer, but like Altus, the spacer and the spring didn't come up to the top of the tube. If there weren't SPECIFIC instructions to use a 1.5 inch spacer, I would have made a 3-4 inch spacer, to get the top to the top of the fork tube.

As it sits, there is NEGATIVE 2" of preload. That is, the fork must compress 2" just for the fork to touch the end of the tube.

So....is the spec wrong, or must it be like that to maintain the proper geometry under the weight of the bike? Or did I get the wrong springs? (Unlikely, considering who I got them from.)

 

Sounds like the wrong springs to me... I'm still using the ones I bought with the same spacer but i'm on my 4 or 5th set of forks

Mine require all teh effort I can muster to get the springs and spacers in the forks

 

Check the PS site for both the proper length of their springs for your application and their install instructions.

 

I followed the instructions exactly, as stated above.

I talked with a tech rep at PS and with Chacal. PS gives a single spacer length for 1980 - 1983, but the 82-83 model forks are SIGNIFICANTLY different due to the air valve. The number is basically for 1.5 inches MORE preload, which is what I plan to do with a 130mm + 38mm spacer for a total of 168 mm, or 6.6 inches. Actually, I'm going to try 6 inches first, because that's what they had at home depot....but close enough.

I'll let you all know how it goes, hopefully tomorrow afternoon.

 

Your front fork springs should be the 11-1106. From their instruction sheet: "Most motorcycles need between 3/4" and 1" of pre-load. As a rough rule of thumb, the fork spring (figure 2) or fork spring and spacer combination (figure 3) should be at least flush (or above) the top of
the fork tube with the forks fully extended. This is true for most motorcycles because their fork caps are between 3/4" to 1" long meaning that they will screw into the fork tube the same distance. For fork caps longer than 1", you must calculate the pre-load length so the fork spring or fork spring/spacer combination will be below the edge of the fork tube. If your fork caps have adjustable pre-load settings or are recessed below the edge of the fork tube (circlip type), then they are usually much longer than the 3/4" to 1" caps and must be measured accordingly."
PS fork spring install sheet

 

You missed the part of the instruction sheet where it says "Check the spacer length requirement ... in the enclosed supplement. If not listed, ... calculate the pre-load." and also "If your fork caps ... are recessed below the edge of the fork tube (circlip type), then they are usually much longer than the 3/4" to 1" caps and must be measured accordingly."

Since my motorcycle was on the chart, I didn't calculate the preload. Since it has recessed caps, I can't just set it to the top of the tube and be right.

I can, however, now report confidently that 6" is WAAAAY too much. I don't think I have any sag at all!! 5 inches is what the PS tech rep recommended (1 inch above the tube), but I'm thinking 4", or at the fork tube level might be best for me. If I follow the instructions and give it 1" of preload, though, I'll need about a 3 inch spacer. I'll do all and measure the sag. I think I'm going for 40mm based on what I've read for how I ride.

By the time I am done we will all know confidently what it should be.

 

So I bought some 4", 3.5", and 3" spacers. I ended up putting in the 4" after calculating that the distance from the top of the spring to where the cap sits was about 3 inches, I tried to give it an inch. That gave me (230 lbs) 30mm of sag. Not quite enough, but I'm going with it for now because I ride with a passenger or on the freeway pretty much constantly.

I'm going to try that for awhile and then go to 3.5 inches, which will (I think) give me the 40mm of sag that is recommended for street use for our bikes. (30% of full travel)

I think the moral of the story is that you should start with about 3.5-4.5 inches depending on your weight, and cut down until you get the right amount of sag, or it feels right for you. It's pretty easy to change out the spacers once you get the hang of it.

Also, I've been using 1/2 inch plumbing pipe from the hardware store. Comes in pre cut lengths and only a buck each. I'm going to return them and go with the 15 cent, yes that's $0.15 plastic tube I found near the same place. So $6 deposit to test, and 30 cents final cut. Not bad.