GL1500 Harsh Ride (progressive suspension)

[DenverWinger]

Okay - so I'm usually the guy with replies or advice but been reading all these posts lately about suspension and I'm no expert here, so I'll actually post a question

Bike is '93 Aspy, PO installed lots of aftermarket stuff like HO Alternator, High Power stereo system W/CD changer, pretty much complete "SE" package aftermarket lights, he thankfully skipped the aftermarket Chrome farkles, has CB installed... etc etc etc

He also installed a set of Progressive 416 rear shocks. They are fine from what I can tell (don't leak fluid or air) but I've never ridden a 1500 with stock suspension so I have nothing to compare with. And with all the other add-ons I have no reason to believe he didn't put Progressive springs in the forks, too. Front suspension is my main question.

My best comparison is my 1100, which to best of my knowledge is totally OEM suspension. It rides much more like a "Road Sofa" than the 1500. My description of the ride on the 1500 is it is much "Harsher" than the 1100.

The 1500 down the Interstate Hwy is pretty much fine, but I note in the city it feels every last crack in the pavement, especially in the front. Recessed manhole covers will jar your teeth out. Sometimes I worry about cracking tupperware parts when hitting a tiny bump or crack in the road. The 1100 will certainly feel the same bump, but it won't launch you off your seat. Feels like the tires on the 1500 are completely solid, not filled with air.

Okay, I'm exaggerating a little, but at the same time the 1500 is not the "Road Sofa" ride I would expect it to be.

Front anti-dive works as it should, otherwise good front suspension travel on dips. No fluid leaks in the forks. Just a harsh ride.

I replaced a 7 yr old front Elite 3 summer before last with a new E4, that smoothed out the front a little, but still feels pavement defects (little cracks and tiny bumps) severely.

Is a "Harsh" ride to be expected from aftermarket Progressive suspension?

I suppose I could take the front forks apart, but seems when forks need service they get mushier rather than harsher when service is needed. No 'visible' evidence of service needed....

Accepting comments/advice below.....

[Sadanorakman]

I think some find the front progressives a little harsh, but fork oil (grade and quantity) apparently has an awful lot to do with that. Some have gone for a 5 weight oil to reduce the harshness compared to 'standard' 10 weight oil. Is it possible that the original owner filed the forks with 15 weight? Now that would tend to make the front end harsh.

Quite possible that the oil in the rear shocks is of an inappropriate grade too.

I'm interested in a pair of 416's myself (sadly now discontinued), but I've been looking for three or four years to find a decent used pair that I can afford, so if you decide to take those off and return to the bike to stock rear suspension, please offer them to me!


.....And, what tire pressures are you running?

[DenverWinger]

Ya - 416's are certainly "unobtanium".....

I run 44 PSI rear, 40 PSI front. I could soften the front tire a smidge, but I don't want to start cupping it.....

[Sadanorakman]

Ya - 416's are certainly "unobtanium".....

I run 44 PSI rear, 40 PSI front. I could soften the front tire a smidge, but I don't want to start cupping it.....

Well I WAS running 42 Front, 44 Rear on my GL1500 following advice right here in the Goldwingdocs forums, and was liking the accuracy and lightness of steering, but I did get a bit of breakaway and squirreling of the rear under hard acceleration on a few slightly greasy roads, which also made me become much more mindful of the limits of grip on the front tire.

I then recently found a video by Max McAllister of Traxxion Dynamics arguing that cupping is predominantly down to inadequate damping, and that it's pretty dumb to over-inflate your tires, massively reducing their contact patch and hence level of grip and therefore safety.

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Now I always consider the source when researching a topic, and do appreciate Max has motivation to state this, as he represents a company that makes upgraded suspension systems! He does however make a compelling argument, and Mother Honda also recommends much lower pressures too, and you'd like to think that the bike's designer and manufacturer have got a slight clue of what they are talking about.

So I have thought again, and now I run 38 Front 40 Rear. the result is a softer ride, and MUCH increased grip. This is evident alone from the increased resistance to steering at a stand-still: That front tire is really gripping the road now.

Now I appreciate many of my American peers are keen on maximizing the mileage they get from their tires, and that they may feel it OK to compromise the level of grip (hence safety) to achieve this; that's totally their decision. Personally, I only do 3000 to 5000 miles per year, as I only ride for fun, with the odd commute to work- but again only because it's a nice day.

I think I'll stick with these lower pressures, for better comfort, grip, and therefore safety, and just replace my tires more often!

[WingAdmin]

Fork oil weight is the primary differentiator for smoothness and impact absorption for front forks. I had 15W oil in my 1500, it was far too harsh. 10W works well for me. I think 5W might be a little too thin.

[Charlie1Horse]

One thing about the manufacturer's recommended tire pressure is not so much for tire performance and wear but, for the smoothest ride. Auto manufacturers have, for many years, recommended a tire pressure that gives the smoothest ride possible without compromising safety but, running the recommended pressure will cause uneven tire wear where running a couple of pounds higher pressure might not give quite as smooth a ride but better tire wear for the life of the tire. And, most people don't even realize the difference in the smoothness of the ride. I know that, because of the application, this is not quite the same but the basic rule of thumb is similar.
Russell

[Sadanorakman]

that gives the smoothest ride possible without compromising safety but, running the recommended pressure will cause uneven tire wear where running a couple of pounds higher pressure might not give quite as smooth a ride but better tire wear for the life of the tire.
Russell

Finding the inverse of that in the UK and Europe Russell. Whether it's an EU regulation I don't know, but cars seem to be plated with two sets of tire pressure values: one representative of what should be considered 'normal', and a set of 'eco' pressures. (Often also state values for carrying single passenger or light load vs full vehicle with full luggage). Often therefore get four sets of figures stated on the plates.

The normal pressures stated are those that genuinely seem to give even tread wear and an ok ride.

The 'eco' pressures (which are higher of course) give a harsher ride, and tend to wear out the centres of the treads more quickly than the edges, obviously because of deformation due to over-inflation!

Not sure quite how good for the planet, an idea is, when it knocks 30% off the useful mileage lifespan of your tires, whilst returning 1 or 2 mpg increase in economy (on cars that do 40 to 50mpg). (UK gallons are 4.546 Litres as opposed to U.S. gallon of 3.785 litres)). I think most European countries measure vehicle fuel economy in litres of fuel used per 100km.

[DenverWinger]

I may try dropping the tire pressure a couple ticks, that will help some.

I also considered fork oil change, but I hesitate on this.

If the forks have progressive springs as I suspect, (there's 416's on the rear) an oil change is likely to be a bigger project than I'm equipped to do. This is an Aspy not an SE so I doubt there's Shrader valves in the fork caps (haven't looked). And getting the progressive springs compressed enough to get the caps back on the forks will probably mean removing the forks from the bike and inventing a jig to compress the springs. OEM springs not so hard to compress, can be done without removing forks.

Maybe the PO had the foresight to drill/tap the fork caps for a Shrader valve or a plug of some sort. If so, that should make changing fork oil a lot easier.

Too cold to worry about it today (only 5 degrees right now).

Been a cold long Winter in Denver this year. I'm tired of it, bring on Spring!

[Sadanorakman]

This is an Aspy not an SE so I doubt there's Shrader valves in the fork caps (haven't looked).

I agree. I think they got them from about 1997, but I doubt a 93 Aspy has them unless as you say the PO took measures.

I still think that your answer will unfortunately be to change the fork oil. Maybe they've already got 15 weight in. As WIngadmin says. I think 10 weight is about right, though I never personally tried anything thinner.

[phlaug]

So I have thought again, and now I run 38 Front 40 Rear. the result is a softer ride, and MUCH increased grip. This is evident alone from the increased resistance to steering at a stand-still: That front tire is really gripping the road now.

I think I'll stick with these lower pressures, for better comfort, grip, and therefore safety, and just replace my tires more often!

100%! Grip is what the tires are for an proper pressure is the key to grip. Longevity of the tire be damned. (I know tires ain’t cheap and I don’t enjoy pulling the rear off my GL1500, but cheaper than medical bills and more enjoyable than time on my back in the hospital.

(If anyone doesn’t think a few extra PSI don’t matter you can read this article and may be convinced https://www.motorsportmagazine.com/arti ... you-crash/ )

[newday777]

The harsh ride you explained in hitting the manhole covers and bumps is most likely from old fork oil. Too many wing riders fail to change their fork oil often enough and get the harsh ride you are experiencing. I highly recommend fork oil changes at most 20,000 miles. Yearly is a good practice if you want the best ride. If you haven't been into the forks since you bought this bike, do it. Don't expect to get an easy answer as you will just be deluding yourself. Get the tools needed to do the job or pay someone to do it.

[Wingsconsin]

The Progressive Springs requires a different amount of Fork oil than OEM -
The best Oil weight from my experience is 10 wt for these front ends -
Worn bushings in the forks can cause 'striction' - a term that means sticky friction - Even though the P.O dropped in new Springs ;
.....they may not have re-built the forks completely. -
My formula for cushy ride is simple -
Hard Suspension ? Soft Tires!
Soft Suspension? Hard Tires !
I prefer the former

Things to consider

[97serider]

I put progressive fork springs in my 97 SE 1500 with the recommended 15wt oil and found it to be harsh like you described. Recently changed the oil to 10 wt and it feels better. I run my front tire at 40 psi and no air pressure for the front shocks, not sure about differences for the aspencade. I would start with changing the fork oil.

[denism]

If still having problems after trying the recommended fixes, you might try removing the front wheel, forks, etc. and re-installing them. I'm not familiar with the 1500, but if whoever had them off last did not follow the service-manual installation procedure to the letter, you can have stiction from binding between the forks. Perhaps, if you get to that point, someone here can recommend the procedure, or it may be online. A repair manual should have it as well. Doing this is a pain on my GL!000, so I imagine it is really a pain and a lot of work and time on the 1500. Hopefully, one of the easier-to-implement recommendations fixes the problem.

[cwinn]

Wingsconsin has the most likely explanation. But I must emphasize what he said about fork oil quantity. Progressive Suspension recommends a much lower fork oil level (less oil) than OEM. This partly compensates for the additional volume the Progressive springs displace compared to the OEM springs + spacer, & it makes the air volume in the forks much larger, thereby reducing the progressive air spring effect. See their website for oil level/quantity/weight.
I've also made the mistake of adding too much spring preload when installing aftermarket springs in the belief that it would help handling. See Progressive Suspension's website for help judging if your wing front suspension is compressing the right amount, or if its preload may be wrong. Unless you & your bike are much heavier or lighter than average, their recommendations are very good.
And finally, don't forget the basics. If the front axle was installed/tightened poorly & put the front forks in a bind, this will cause harshness like you describe, & eventually worn fork bushings & fork seal leaks. Install the front axle. Hold the front axle on the left end while tightening the retaining bolt on the right end. Then make sure the left end has found its unbound neutral place by putting the front wheel against a wall & bouncing the front suspension to allow the fork to find its unbound neutral place (afterwords, you should be able to put the bike on its centerstand, & push/pull the left fork in & out & feel that the fork moves easily just a few thousandths & tries to return to its neutral place. Then tighten the axle pinch bolts on both forks.

[Marc861]

I know this isn't exactly the same but back when I had my 1500 trike it had the same thing described.I did seals and bushings and reused the Progressives that were in there.I tried several different weights and wasn't happy with any of them.I came across a post from Crystal Pistol where he was talking about accidentally getting the wrong Progressives in his and the differences in spring ratios between them.He felt the ratios selected for the 1500 allowed the spring to almost be bottomed out of the softer part of the spring and end up riding on the much harder portion the majority of the time.He had used 1200 springs and another that I don't remember.They had a stiffer soft part and a softer hard part and gave him a better ride.Borrowing on that I did what Progressive says not I added some air to the forks and it rode much better.I replaced the Progressives with a straight wound spring and never looked back.I believe his post is on this forum as well.

[DenverWinger]

The harsh ride you explained in hitting the manhole covers and bumps is most likely from old fork oil.

My thinking as well....

I put progressive fork springs in my 97 SE 1500 with the recommended 15wt oil and found it to be harsh like you described. Recently changed the oil to 10 wt and it feels better. I run my front tire at 40 psi and no air pressure for the front shocks, not sure about differences for the aspencade. I would start with changing the fork oil.

93 Aspy doesn't come with schrader valves in the fork caps, but who knows what PO did to this bike. He bought it in '95 and did a lot of stuff to it. There might be schrader valves or maybe a threaded plug added to the fork caps, been too cold and I haven't been in any kind of "Mainenance Mode" to even look. I'm so tired of winter this year already.....

If still having problems after trying the recommended fixes, you might try removing the front wheel, forks, etc. and re-installing them. I'm not familiar with the 1500, but if whoever had them off last did not follow the service-manual installation procedure to the letter, you can have stiction from binding between the forks.

Very good comment! But I just had the front wheel off last year for a new tire, absolutely no issue with putting the axle back in and no evidence of stiction.

Unless you & your bike are much heavier or lighter than average, their recommendations are very good.

Deb and I combined are about 320 lbs, so this would be a moderate load 2-up on this bike. And outside of "Cross-Country" trips my riding is mostly just commutes to work solo.

___________________________

I thank you all for your comments!

I'm sure a fork oil change would make a world of difference. I'll also try 37 PSI front instead of 41 and see how that feels..

No reason to believe there's any kind of mis-alignment in the forks as front tire change went so easy.

Kinda scared of pulling the fork caps to refill fork oil if the PO didn't add a fill plug, Progressive springs are taller and stiffer than OEM and getting caps back on will be a real "BEAR" of a job.

Then again, I don't know for sure PO changed the springs. Might still be OEM, but considering all the other upgrades I found on this bike, I'm pretty sure he did the forks, too. If he didn't and springs are OEM, the oil must be really bad......

Hate to do full disassembly on the forks, they don't leak, and other than the "Harsh" ride nothing wrong with them that I can tell....

If the weather ever warms up to where I feel like spending time in my unheated detached garage I'll put the stereo on, drink a beer, pull the top caps off the forks and see if there's a valve or plug so that I can do an oil change on them without removing the forks and having to beat the springs back in there with a sledge hammer and welding the caps back on really quick before the springs can escape!

Thanks again!

~Mark

[newday777]

Yuk Yuk on the sledge and welding the cap quick!

As a technique for getting the caps back on without a special tool, there was a few threads some years ago(maybe here or on the old SSGWFacts forum) to use a strap hooked to the lower tree sides, up over your shoulders to hold your back in place, to get more downward force with the ratchet to start the cap a bit easier.

I prefer to use straight wound springs for the weight of rider and load apposed to using "the one size fits all" progressive springs. Far better ride in my findings and that of good suspension gurus.

[landisr]

My $.02

I am extremely happy with the ride on my '94A. Bought new, 205k miles and riding/purring like a Tiger. Stock suspension. 0 psi in forks. 15-20 psi in back. 5W ATF in forks. 36F/41R.

You mention the anti-dive works good. Is it only 'active' when it's supposed to be? That is, is it possibly stuck active such that it needs attention?

YMMV. Good luck.

Ron in AZ

[Fatboy46]

1- air pressure? 2- oil 3- tire pressure.