TOO Much Wallow in sweepers

[gixerbike1]

Hey Folks,

I now have a new issue I'd like to get some input on.

First let me give a run down of what's been done to the suspension.

1.) I pulled the forks apart and replaced the folk seals, new Progressive fork springs (85kg) and 20w fork oil. (followed the manual on the amount.)

2.) New rear shocks that i got from Parts N More with them set to softest at first, moved them up two notches currently.

3.) Swing arm needle bearings were checked and are in great shape so i cleaned them up and packed them with new grease.

When I would ride the bike it seemed too soft and wallowed around on a couple of sweepers i use to test the bike for stability.

Nothing crazy fast, about 60 to 65 MPH.

This weekend a friend of mine took a look at the front end after we pulled it down.He checked the headset bearings everything was tight and had smooth movement from lock to lock.

The forks didn't have any play in them and the action up and down was smooth.

He didn't like the feel of the wheel bearings so we replaeced those with new bearings and he checked everything else to make sure it was safe.

We put the front end back together and tightened everything up starting with the axle and finished with the fender and then torgued up the caliper bolts.

I took the bike for a spin and it still wants to wallow around under me in right and left hand sweepers, doesn't fell as if it's going to throw me off, but it does have me a bit concerned.

After that ride we moved the rear shocks up one more notch for a firmer ride and moved the forks up 10mm in the triple trees.

I took her out again, I will admit the ride is a bit better and firmer, however the wallowing is still there.

Should i go to the 91kg springs from progressive since I'm 225lbs, maybe a fork brace?:-k

Any thoughts or idea's would be greatly appreciated.

Tommy

 

[posplayr]

Hey Folks,

I now have a new issue I'd like to get some input on.

First let me give a run down of what's been done to the suspension.

1.) I pulled the forks apart and replaced the folk seals, new Progressive fork springs (85kg) and 20w fork oil. (followed the manual on the amount.)

2.) New rear shocks that i got from Parts N More with them set to softest at first, moved them up two notches currently.

3.) Swing arm needle bearings were checked and are in great shape so i cleaned them up and packed them with new grease.

When I would ride the bike it seemed too soft and wallowed around on a couple of sweepers i use to test the bike for stability.

Nothing crazy fast, about 60 to 65 MPH.

This weekend a friend of mine took a look at the front end after we pulled it down.He checked the headset bearings everything was tight and had smooth movement from lock to lock.

The forks didn't have any play in them and the action up and down was smooth.

He didn't like the feel of the wheel bearings so we replaeced those with new bearings and he checked everything else to make sure it was safe.

We put the front end back together and tightened everything up starting with the axle and finished with the fender and then torgued up the caliper bolts.

I took the bike for a spin and it still wants to wallow around under me in right and left hand sweepers, doesn't fell as if it's going to throw me off, but it does have me a bit concerned.

After that ride we moved the rear shocks up one more notch for a firmer ride and moved the forks up 10mm in the triple trees.

I took her out again, I will admit the ride is a bit better and firmer, however the wallowing is still there.

Should i go to the 91kg springs from progressive since I'm 225lbs, maybe a fork brace?:-k

Any thoughts or idea's would be greatly appreciated.

Tommy

Have you checked the sag of both front and back? Do a search for directions. There is an Ohlins Link as well as other on how to do it. If the back spring is too soft it can cause wollering or not enough air in the rear tire.


I suspect you will need a stiffer spring at 225lbs and a fork brace will improve your bike. Since the bike looks I'm assuming you are trying to do the best you can with stock. My GS750 is close to stock and rides well although there are limits with the tall bias ply tiers.

It has:
progressive front springs
fork brace
avon tires ft/bk
Hagon aftermarket shocks

This alone along with basic maintenace rides well but there are limits as mentioned before.

Make sure your steering bearing are tightened sufficently as well.

I have a set of cartidge emulators for 35mm forks as well but have not put them in.
Any thoughts or idea's would be greatly appreciated.

 

[TheCafeKid]

Did you install a spacer with your fork springs(not sure if your model requires one or not). Even if progressive doesn't say to install a spacer, you may find you want one, or if you did you mght want a longer one. A little more preload by using a longer spacer will stiffen the forks a bit. A fork brace will help keep the forks moving in unison while heeled over.

 

[KiwiGS]

How are your tyre pressures?, Has some one sneaked a too big rear tyre on?.........

 

[Sandy]

You mentioned that you weren't going crazy fast when this was happening. The setup you have should work well for the speeds you mention. I have two suggestions the first being to find a stretch of straight road that has some fairly good dips, like frost heaves, in it and see how the suspension settles when driven quickly over them. It should obviously sag and rebound equally front and rear. Too much spring and not enough dampening will give you a pogo stick type of feel, not enough spring and too much dampening will give you a lot of sag but a harsh ride. Both ends should feel the same, if not adjust accordingly. The second suggestion is check the tires for wear, a cupped front or mismatched tires and wear patterns can and will cause exactly what you're talking about. Installing a fork brace helps these old motorcycles but they can also amplify any existing handling problems. Get the chassis and suspension sorted first. A wallow or slow weave is usually a sign of bad swingarm bearings or worn tires, a quick wobble or wiggle is usually a sign of something not right up front. The 650E should be a good handling bike in anything but overly aggressive cornering speeds. Let us know what you find.

 

[BassCliff]

Hi,

Did you install the inexpensive MDI/EMGO shocks? If so, those are really cheap and flimsy bushings, plastic and foam rubber.

​

I found some better bushings to use at my local AutoZone. They also carry the same parts in a different package at Napa parts stores.

Old bushings that were bundled with the shocks, after about 1000 miles:

These are the bushings I found at AutoZone:

I had to drill out the middle a little so that they fit on the shock studs and use a little lubricant to press them into the shock eye:

The new bushings really firmed up the back end. There's a little more rubber there than you need. You can trim it to fit or just tighten the bolts until the extra gets pinched off. I had to check the torque on the shock bolts over a few days and tighten as necessary as the rubber compressed and was cut by the washers.

Thank you for your indulgence,

BassCliff

 

[posplayr]

You mentioned that you weren't going crazy fast when this was happening. The setup you have should work well for the speeds you mention. I have two suggestions the first being to find a stretch of straight road that has some fairly good dips, like frost heaves, in it and see how the suspension settles when driven quickly over them. It should obviously sag and rebound equally front and rear. Too much spring and not enough dampening will give you a pogo stick type of feel, not enough spring and too much dampening will give you a lot of sag but a harsh ride. Both ends should feel the same, if not adjust accordingly. The second suggestion is check the tires for wear, a cupped front or mismatched tires and wear patterns can and will cause exactly what you're talking about. Installing a fork brace helps these old motorcycles but they can also amplify any existing handling problems. Get the chassis and suspension sorted first. A wallow or slow weave is usually a sign of bad swingarm bearings or worn tires, a quick wobble or wiggle is usually a sign of something not right up front. The 650E should be a good handling bike in anything but overly aggressive cornering speeds. Let us know what you find.

Sandy,
That idea of riding over dips is a great idea. It basically captures all of the tuning concepts I was read up about over the weekend.

http://www.factorypro.com/tech/Suspension_Setting.html

http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm

http://www.rc51.org/susp.htm


Spring rate,
Compression Damping
Rebound Damping

Some had suggested a really simple test of weighting the foot pegs and looking for the bike to come to a stable condition within 1 sec. This dynamic input is even better. I will have to really how my bike handles the bumps.

Now I just gotta find some frost heaves

 

[gixerbike1]

Hi,

Did you install the inexpensive MDI/EMGO shocks? If so, those are really cheap and flimsy bushings, plastic and foam rubber.

​

BassCliff

Bass,

I sure did and i will be visiting autozone tonight to get those bushing and they will be replaced tonight.


CafeKid,

The springs i got from progressive were longer than the stock units and it took two of use to get the caps back on.

They made a huge difference.

KiwiGS,

I did install a larger tire, the bike calls for a 110/90-18 I went to a 130/90-18, You think that might be too tall ?

Sandy,

The tires are new, maybe 50 miles on them, The wallowing that you described is what I'm experiencing, it's kind of a slow rhythmic wallowing.

I plan to check the tire pressure to make sure it's correct.

The maintenance manual also said something about the wheel bearings being a possible cause factor for the wallowing.

Since just about everything else on the bike is new, I might as well order the swing arm bearings and replace them and the Wheel bearings since i already have those on hand.

Well,

Thanks for all the input and Let me know if you guys have any other thoughts or suggestions.

Tommy

 

[Sandy]

Now I just gotta find some frost heaves

Come north young man. Lots of suspension tuning opportunities here.

 

[TheCafeKid]

Sandy,
That idea of riding over dips is a great idea. It basically captures all of the tuning concepts I was read up about over the weekend.

http://www.factorypro.com/tech/Suspension_Setting.html

http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm

http://www.rc51.org/susp.htm


Spring rate,
Compression Damping
Rebound Damping

Some had suggested a really simple test of weighting the foot pegs and looking for the bike to come to a stable condition within 1 sec. This dynamic input is even better. I will have to really how my bike handles the bumps.

Now I just gotta find some frost heaves

Come to Ohio... Frost Heave capitol of the world... I can show you some frost heaved roads that will make your balls sweat...

 

[posplayr]

http://www.denniskirk.com/jsp/tpl/c...8&store=Main&category=40402&_requestid=729252

I'm sure our OP really wants to keep the bike stock but improve handling.

Something cheap to consider since you have those taller rear springs is to go with a lower aspect tire in the rear.

I theorized that on my ED, it was rear tire side wall flex that was causing a similar rear end wollering. Mine was most noticeable when the rear was over loaded. Going into a fast sweeper with "frost heave" undulations in the road, my rear end would bounce (do to insufficent spring rate) and it would cause the bike to lay down in unision with the rear bounce.

It was as if, when the rear went down more weight went onto the rear, flexing the tire sidewall and laying the bike down (low side). This only happened in a turn with undulations.

Now that I have stiffer rear springs and 60 series radial it is entirely gone away. My GS750E does something similar, but I never go as fast on it as the ED :-\\\.

So here is the thought for a cheap upgrade after he any basic problems sorted. A GS1100E swing arm would be nice, as I'm not sure how big of a tire will fit comfortably in his 650 swing arm. He has a 130 now but suspect is pinched on a narow rim.

What if he gets another rear time (great OP says), along with a similar 80-81 GS750E wheel which will carry a 130/90-18 with no trouble. But instead of going 130/90-18 go 130/70-18 for a much shorter sidewall with much more stiffness. Avon has a nice one in the AM26 for only $73. The 70 series v.s. 90 series is only .3" lower at the axle.


Avon Rear AM26 Roadrider 130/70V-18 Blackwall Tire
Dennis Kirk Part #: 543178
Manufacturer Part #: ROADRIDER
Aspect Ratio: 70
Construction: Bias
Position: Rear
Rim Size: 18
Sidewall: Blackwall
Speed Rating: V
Tire Classification: Sport/Touring
Tube Type: Tube or Tubeless
Units: Each
Width: 130

So a cool upgrade would be to do both the wheel/tire combo with the GS1100E swing arm and still look completely stock and would certainly help any 60-80 mph sweepers.


What do u guys think to stave off his GSXR conversion urges?

 

[Billy Ricks]

Going back to the correct size tire or one just one size wider would be the easiest thing to do. Sounds like too soft of springs on the shocks is the big problem.

 

[KiwiGS]

....snip....
KiwiGS,

I did install a larger tire, the bike calls for a 110/90-18 I went to a 130/90-18, You think that might be too tall ?

....snip...

I have a bike (VT250) that was doing exactly what you described, I checked every thing on it and couldn't fix the problem.
It wasnt until I saw it parked next to my GS1000 that I realised that it had the same width rear hoop.
Once I put the right size tyre on 99% of my handling problems were gone.
Might not be your only issue but I like to use the KISS method when I work through problems...

 

[gixerbike1]

New Tire

New Tire

Posplayr,

Got a new Avon Roadrider AM26 in 130/70-18 on the way from www.motorcyclesuperstore.com 85.00 shipped.

I've replaced the bushings on the rear shocks, MUCH better material from Autozone!!

I'm going to replace the Wheel bearings this weekend since i have to pull the wheel to replace the tire, The Carrier bearing has been replaced already.

Thanks for all the input and help, I'll let you guys know how it handles with the new tire, bearings and fresh shock bushings when i get it all back together....AGAIN!!

Tommy

 

[Steve]

All of the above information is good (and correct), but one more thing you might want to check.

Any particular reason you went with 20w fork oil? :-k

The heavier oil might be slowing down the reaction of the forks so much that the rear is trying to compensate. This constantly changing suspension might be a contributing factor to your "wallow". A lighter fork oil will allow the front suspension to respond to the pavement quicker and settle back to a neutral position quicker.

Not that hard to change the oil, and it's certainly about the cheapest change you can do to the suspension.

.

 

[posplayr]

Posplayr,

Got a new Avon Roadrider AM26 in 130/70-18 on the way from www.motorcyclesuperstore.com 85.00 shipped.

I've replaced the bushings on the rear shocks, MUCH better material from Autozone!!

I'm going to replace the Wheel bearings this weekend since i have to pull the wheel to replace the tire, The Carrier bearing has been replaced already.

Thanks for all the input and help, I'll let you guys know how it handles with the new tire, bearings and fresh shock bushings when i get it all back together....AGAIN!!

Tommy

Make sure that you check your sag numbers (front and back) to see if you are close. Do a search if you don't already know how to do this.

Not sure if what I described as my problem is occurring with you but the weight transfer from front to back (when the rear compressed more than front) is what caused the woller (similar to what Steve is describing). In mine I had too stiff of a front due to too much stack height in my springs with Progressives and Cartridge emulators. 20 wt could contribute to the same thing. Front doesn't compress, the rear does and the weight transfer front to rear puts more sidewall pressure on a tall rear tire. You have aggravated the problem also by going two sizes over as well.

I would get a stock GS wheel that normally carried a 120/90-18 tire. The 130/70-18 will fit it nicely. When you change the tire, I would drop the front down by the 0.3" to compensate for the shorter rear tire as well. You loosen the triple clamp and allow the stanshions to slip up by the 0.3".
At least you will have separated the rake change from the side wall change this way.

Also what size rear wheel do you have? You might have improved things somewhat with the shorter side wall, but you still going a tire two size over v.s. just one.

I'm afraid you might have selective reading and are jumping to what seems like an easy solution in a new rear tire. Before you change the rear tire follow this:

1.) If you are putting something back to stock like wheel bearings and bushings fine. Hopefully this gets rid of some variables and will not hurt.

2.) Check your Ft/Back Sag numbers to confirm your spring rates are OK and adjust preload accordingly.

3.) Go back to the 15 wt oil in front.

4.) Road test over the dippy frost heaves as described by Sandy. My problem manifested itself when in a banked heaving conditions only.

http://www.thegsresources.com/_forum/showpost.php?p=1197199&postcount=5

Put tie straps on the front forks to see how much travel you are getting. Heavier oil is not really a replacement for more preload. I'm running 15 wt in all my bikes.

See how the bikes rides and if the problem has gone away or been moderated then......

5.) Change the rear tire prefereably on a wider wheel. In this order you will be able to tell the difference due to the wider tire independent of all the other potential problems. This is non stock and an experiment (also increase tire pressure).

 

[posplayr]

more tire size discussion; remember every one does not push their bike the same way

http://www.thegsresources.com/_forum/showthread.php?t=150504


Also here is a description of the problem I was having

http://www.thegsresources.com/_forum/showthread.php?t=140521&highlight=sag

Looking at it reminded me that with those avons you can really bone them upon pressure. I would also confim if there is a difference between say going from 30 psi rear to 42 psi rear as suggested by Salty:

Where did you get your tyre pressures? Avon recommends 36F 42 Rear for my bike... A little more pressure should help to stiffen the sidewall.

 

[Guest]

Are you riding this GS after owning a modern sportbike? Just wondered (with your handle and sig graphic)...they do feel different, esp. whilst cornering. The older GSs while not unsafe, are nowhere as confidence-inspiring as the modern bikes, and may well feel 'flexy' when pushed in the corners, compared to a Gixxer....an altogether animal, in terms of the tires, chassis, and geometry.
Tony.

 

[gixerbike1]

Tire and rim size

Tire and rim size

Make sure that you check your sag numbers (front and back) to see if you are close. Do a search if you don't already know how to do this.

I'm going to do that this afternoon, i have the steps saved as a favorite.

Not sure if what I described as my problem is occurring with you but the weight transfer from front to back (when the rear compressed more than front) is what caused the woller (similar to what Steve is describing). In mine I had too stiff of a front due to too much stack height in my springs with Progressives and Cartridge emulators. 20 wt could contribute to the same thing. Front doesn't compress, the rear does and the weight transfer front to rear puts more sidewall pressure on a tall rear tire. You have aggravated the problem also by going two sizes over as well.

The front isn't too stiff and has good movement, it's actually a little softer that i like.

The wallowing i feel is coming from under my rump and when your heeled over it's as if the bike moves away from the pavement and then back toward the pavement.

It's like the bike is going up and down, but it's doing it sideways, if that makes sense

The front end is stable, and the reason for the 20wt oil was that I had the stock springs and it was WAY TOO soft and had too much sag.

I would get a stock GS wheel that normally carried a 120/90-18 tire. The 130/70-18 will fit it nicely. When you change the tire, I would drop the front down by the 0.3" to compensate for the shorter rear tire as well. You lossen the triple clamp and allow the stansions to slip up by the 0.3".
At least you will have separeted the rake change from the side wall change this way.

Also what size rear wheel do you have? You might have improved things somewhat with the shorter side wall, but you still going a tire two size over v.s. just one.

I checked the tire chart for the tire I just ordered and the manufacturer states that the tire will work fine on rims from 3" to 4" my rim is 3.75" So this shouldn't be a problem.

I've already raised the forks in the trees by 10MM, should i go more ?

I'm afraid you might have selective reading and are jumping to what seems like an easy solution in a new rear tire.

Not really, I just realize that the tire sidewall is awefully tall and the shocks are brand new and were adjusted up to where the ride is firm now and i know the needle bearings in the swing arm are good and have new grease in them.

I checked for excess play in the swingarm before i put things back together and it was good to go.

So, to me the most logical and simple answer was the tire, of course when i got the dunlops i didn't have anyway to check what size rims these would properly work on, the front size is stock.

Before you change the rear tire follow this:

1.) If you are putting something back to stock like wheel bearings and bushings fine. Hopefully this gets rid of some variables and will not hurt.

Cool

2.) Check your Ft/Back Sag numbers to confirm your spring rates are OK and adjust preload accordingly.

I plan on doing this after work, last night was raining a bit too much.

3.) Go back to the 15 wt oil in front.

I can do that.

4.) Road test over the dippy frost heaves as described by Sandy. My problem manifested itself when in a banked heaving conditions the most.

Don't really have any of those here in Va. pot holes mostly

http://www.thegsresources.com/_forum/showpost.php?p=1197199&postcount=5

Put tie straps on the front forks to see how much travel you are getting. Heavier oil is not really a replacement for more preload. I'm running 15 wt in all my bikes.

Is there a chance I might need to cut my springs and install a spacer ?

See how the bikes rides and if the problem has gone away or been moderated.

Thats just what i plan to do, I'll post my result's tonight for the sag measurements front and rear to see what you think.

5.) Then change the rear tire prefereably on a wider wheel.

I'm not sure what wheel will work with this bike since most of the GS's are shaft drive, any idea's on that one ?

In this order you will be able to tell the difference due to the wider tire independent of all the other potential problems.

I will do all of the other stuff you have listed above before going to the different tire, I will see if i can cancel the order before it ships out today.

This is non stock and an experiment.

True that

Thanks for all the input and i'll keep you updated.

Tommy

 

[Turtleface]

I agree with Jim. You're changing a LOT of variables at once. Before you do anything, check your sag measurements and all that. There should be a thread around the boards for setting up suspension, or you could google for one of the many available. You need to know where you're at, before you can know where to go.