Progressive springs,,,, now rides bad!!

[feelergaugephil]

I changed out my sagging 81 GS1000G front fork springs because it would bottom out, so, I put new progressive fork springs in (correct ones for my year/model) well I noticed that the progressive ones were smaller and came with plastic tubing (for spacering) so, I cut the tubing to exactly the same length as the original springs (so now with spacer and progressive springs is the same length)
Well, it rides like POO! very, very twitchy and does not like bumps in the road....
Should I take the spacers out???????????????
OH, and it has no air pressure and correct amount of fork fluid.
Phil.

[jknappsax]

The idea is to use spacers until you get 20-30 mm static sag when you sit on the bike. It varies from rider to rider, due to weight. With too much preload, the springs might be binding. On my 1978 GS 750, I ran without preload spacers, and it felt pretty good, but I always thought it needed about a 1/2" spacer in each fork; I didn't follow the advice I gave you about static sag, because I hadn't learned about it. Hopefully some other folks will chime in who are more knowledgeable. But I liked the Progressive springs a lot more than the stock springs, which only had about 10k miles on them, so it's not that the springs are cr@p.

[twr1776]

How much sag do you have on the forks between no weight and with you on it? On mine (81 L model) I kept the OEM spacers and added about 1 1/4" to 1 1/2" of the PVC spacer as I recall. I think the instructions have you start with the combo of springs and spacers roughly even with the top of the fork tube before putting the cap on.

[Steve]

Setting the spacer length (preload, or sag) is the proper way to do it. The generally accepted amount is "no more than 25% of the available travel". Measure the extended length of the forks when there is no weight on the front wheel (put the bike on the centerstand). Now get on the bike like you are going to ride it (off the centerstand), bounce the forks a couple of times to settle the suspension, have a helper measure the same points, you are looking for 1 to 1 1/2" inches of sag, based on the typical 6" of travel. If it sags more than that, add length to the spacer, if it sags less, cut some of the spacer off.

Once you get the preload set correctly, you need to ride over some bumps to analyze the reaction of the bike. Progressive suggests 15w oil, but I found that my wrists were hurting because the bike was reacting very sharply to the bumps. I switched to 10w oil and really enjoy the difference in comfort.

.

[marvinsc]

I have heard that the weight of the fork oil makes a big difference. 10-15-20 weight are all options. Progressives made My old 850 (8trackmind's now) handle like a different bike, all for the better.:-D

[Nessism]

Changed to Progressive springs on my 850 and noticed a reduction in ride quality. Thought of changing them back but got used to it. They are definitely on the stiff side if you are a medium-lightweight rider.

[SqDancerLynn1]

Basic guide The spacer should stick about 1" above the fork with all weight OFF the wheel

[tkent02]

I found them a wee bit stiff on a couple 750s, deciding whether or not to use them on the new 1000.
It is sagging, need to do something.

[Nessism]

Basic guide The spacer should stick about 1" above the fork with all weight OFF the wheel

Not trying to be contrary but the basic guide is to have the springs w/spacer equal to the top of the fork tubes; when the top caps are installed there will be approx. 3/4 - 1 inch of compression.

http://www.progressivesuspension.com/pdfs/forkSprings/3055.pdf

[Steve]

Not trying to be contrary but the basic guide is to have the springs w/spacer equal to the top of the fork tubes; when the top caps are installed there will be approx. 3/4 - 1 inch of compression.

I looked through the attached link, but did not see what I have seen in their previous publications, and that is what referred to the maximum of 25% compression (sag) when the bike is ready to ride. Some bikes might have the springs rather flush with the tops of the fork tubes, but I know the 1500 Wings have to have them about 1 to 1 1/2 inch above. 8-[

.

[Nessism]

I found them a wee bit stiff on a couple 750s, deciding whether or not to use them on the new 1000.
It is sagging, need to do something.

I've modified several sets of springs by hacking off some coils, approx. 3" worth, and replaced the lost stack height with a PVC spacer. Works great to increase the spring rate. Might have a go with my old 850 springs so see if I like it better.

[bwringer]

You don't want to know how much preload my GS850 needed, but then again, I'm rather immense and ride quite rapidly. Getting the fork caps back on took an act of congress and many terrible oaths.

I'm guessing either FgPhil is a rather smallish gent and needs less preload, or something is out of alignment and binding.

Another possibility is that Phil fell victim to a very, very common misunderstanding and measured the fork oil level wrong.

The correct method is:
1) Springs OUT

2) Forks COMPRESSED all the way

3) Fork oil level should be no higher than 140mm from the top of the fork tube.

Some bikes specify that the fork oil needs to be lower (a measurement of 150 or 160mm from the top), but this measurement should never be less than 140mm with Progressive springs, or there may not be room for enough air space to allow full fork travel. I suspect this may be what is happening.

You set fork oil level by adding a bit too much fork oil, pumping the forks a few times to get rid of air bubbles, then slurping out the excess fork oil with a large syringe and a piece of hose cut and marked at the correct level.

The volume of fork oil is irrelevant and inaccurate -- the LEVEL must be the same on both sides, and not too high.

[salty_monk]

On my 80 1000G I believe I used a 42mm spacer (it was over a year since I fitted them... just from memory).
I scrapped the factory spacer so just used spring, 42mm PVC & the original "top hat" metal washer.
Come up with that figure by following their instruction sheet.
Rides great, loads better than stock (was losing about half my travel with the stockers & air was a PITA.
15W oil filled up to 140mm from the top.

I weigh 165lb.

Dan

[Hvycrzrtim]

Phil is a fairly average size guy. I ride his GS sometimes and it is squirrely on bumps for me as well, and I am a bit larger than the average bear (6' and around 250lbs). I don't get as much wobble as Phil, but it is definitely there.

[Redman]

Phil,

In addition to all the comments about what to do. Let me make a comment about what not to do. And that comment is: Dont do anything based on the length of the old spring. As the spring fatiques its "free length" changes.

Not sure how to interperet you orginal comment about "cutting the spacer so its the same length as the original spring".

When I replaced mine with PRogressive I recall there being a chart that came with it that suggested what length to have the spacer (but didnt get an new spacer with it) and that length was less than the original spcer length, so I cut the original spacer to the length.