Suspension setup for your weight/riding style

[mcycle-nut]

I put Progressive Suspension springs in my 1100. That made a noticeable difference. It feels firmer on the front, and doesn't wallow about like an elephant doing a slalom. With my 750, I put both Progressive Suspension springs in the front, and Progressive shocks and heavy duty springs on the rear. It's a totally different animal! It's a little stiff, but I can carve with it better! :twisted:
By the way, I'm 6'2" and 270lbs. I guess I'll be looking up at Hommie, as he is a 6'4" monster! :lol:

 

[courier11sec]

Looks like there is only one bushing in your fork. Part #20 in the diagram in the link.
http://houseofmotorcycles.bikebandit.com/partsbandit/oem_schematic_view~schem_dept_id~1009704~section_dept_id~1~section_dept_name~OEM+%28Stock%29+Parts~dept_type_id~2~model_dept_year~1981~model_dept_mfr~Suzuki~model_dept_id~987839~model_dept_name~GS850GLX.asp

Thanks Billy. Looks like I'll be taking the forks further apart than I thought. Hope they look nicer inside than the front brake system did!

 

[Hoomgar]

I put Progressive Suspension springs in my 1100. That made a noticeable difference. It feels firmer on the front, and doesn't wallow about like an elephant doing a slalom. With my 750, I put both Progressive Suspension springs in the front, and Progressive shocks and heavy duty springs on the rear. It's a totally different animal! It's a little stiff, but I can carve with it better! :twisted:
By the way, I'm 6'2" and 270lbs. I guess I'll be looking up at Hommie, as he is a 6'4" monster! :lol:

If we stood beside each other, I would not look bigger than you Kevin :lol:

Great tips Billy, Keith, Kevin and others. Keep them coming. I am going to be re-doing my setup here shortly and want to learn as much as I can.

 

[ruddy]

I replaced my fork springs several years ago with a pair from Progressive Suspension, and they were a big improvement over the stockers. When I replaced my fork seals two years ago, I changed to a 20 weight fork oil and increased the spring preload by 3/8" over Progressive's recommendation. With no air pressure, I find a huge improvement in the damping and a reduction in nose-dive during hard braking. The slightly stiffer springs give me a bit more ride height as well. By the way, I'm 6' and 230 lbs.

 

[Road_Clam]

bloody good call Mr Hoom....


I am about the same size- slightly larger but with 1/10 the riding experience.... and I noticed similar behaviours....

I recently adjust my rears to max - and pumped a few pounds of extra air in the front - it seems to have improved a lot...

but some real science from some of you wizards would'nt go astray:-D

There is a popular misconception about "adjusting" the rear springs on your typical road bike. If you find your rear suspension too soft, cranking up the spring prelaod does NOTHING to remedy bottoming out. Weather your prelaod is on step #1, or step #5, you are not changing the spring rate, you are simply altering the INITIAL prelaod. Suspension gurus will always tell you you first match spring rates to your weight, then you adjust dampening to suit your riding preference. So you "bigger" men, the only way to correctly remedy a soft suspension is to purchase stiffer springs.

The second misconception is cranking up the shock dampening stiffens your suspension, it technically does NOT. When you increase shock dampening, you are effectively SLOWING down the shock piston movement. Yes this does to a certain point make your suspension feel firmer, simply because your shock (or fork) is taking longer to react to road forces.

I am no suspension expert, but I do understand the basics from racing moto-X for 20 years. Bottom line is like others commented, you are VERY limited to improving GS shocks and forks by adjustments.

The suspension on my E model is perfect for me, but I am a wirery 155 lbs soaking wet. I can easily see 250ish lb guys cringing at a pothole in the road @ 45 mph on a GS

 

[Billy Ricks]

Good point on the spring rates Rich. When you consider new shocks talk to the reps to see what spring they recommend for your bike with your weight.

 

[bwringer]

The recommended "heavy duty" spring rate on my Progressive shocks was still too light for me (I'm not quite as tall as Hoom, but I weigh a bit more, and I ride quite briskly.)

After perusing the application charts, I spotted an even heavier spring rate intended for a Gold Wing or somesuch. This turned out to be perfect. Preload position #1 works great for me alone with no luggage. I use position #2 with luggage, position #4 with the missus on board, and #5 with the missus plus luggage.

Now if I could get fork springs in with a heavier rate, I'd be all set. I do have the sag set correctly with a monster spacer and Progressive springs, but I think a heavier spring might be just the ticket. I use 15W fork oil (can't find 20W any more) with 10% - 15% "motor honey" mixed in to thicken it a bit and compensate for 74,000 miles of wear in the damping passages.

I'm also seriously considering stepping up to cartridge emulators and IKON shocks -- after 7 years of abuse, the Progressives are starting to lose a bit of their damping ability.

 

[smegger68]

well i'm closer to 300lbs and I just replaced the fork springs in my '82 1100 ez with Hagon Progressive items. This has transformed the front end and it no longer bottoms out under braking - even when braking really hard

Got some NOS Koni dial-a-rides which a dealer had sitting on his shelf coming tomorrow to replace the Progressive units currently out back. Never could get them set up stiff enough. I had Koni's on my old 1100et and they were perfect. Hoping this sorts me out for the summer!

 

[Nerobro]

If you have bottoming issues on the fork, you can adjust the fork fluid level. The air space in the front fork is critical in bottoming resistance. As the fork compresses the oil doesn't compress, so pressure builds in the airspace. If you have 4" of fork travel, and 5" of airspace.. By the time the fork bottoms you will have 60psi of air pushing the fork down. The forks on a GS550 have an aera of about 1sqin. That works out to a forkspring that's another 60lbin of rate when you're about to bottom.

I know we all hate running air pressure in the forks, but if you're bottoming, a little air pressure can make a huge difference in bottoming resistance. Say.. 5psi of pressure in the forks with our previous example would turn into 85bls of force when the forks are bottomed.

Raising the oil level has a similar but different effect. Starting from 0psi like most of us do.. Instead of the pressure climing linearally, it makes the pressure increse more sharply. Raise the oil level 1/2" and the pressure would be 130psi by the time the forks bottomed.

The rear end isn't so easy.. Short of replacing the shocks there's not a lot you can do. If you have to choose, rebound damping is the MOST important adjustment you can get on a shock. Springs are what hold you up, rebound damping is what stops occilations. If you have a monoshock GS, I heartily recomend a modern GSXR shock. I still need to find out what ZRX shocks will do for my dual shock bike.

I'm 5'5" and 200lbs. I run 1.75" spacers in my 83 550ES forks, I also have the rear preload maxed out. I have the fork tubes as far up in the tripple trees as they'll go on my 1980 550, and I have the rear shocks set to maximum preload.

Bwinger: It depends on how nuts you wanna be. Motor oil isn't a bad choice for forks, so long as you can get it in the proper weight. 20w oil is available on bikebandit as well. If you wanna be really retentive, I can hook you up with a source of sillicone shock oil.

(My fork pressure numbers are correct given the numbers I gave... they are not specific for any particular bike... I would do measurements but It woudl only related to my specific forks.)

 

[Hoomgar]

Good info guys. I am already getting new ideas from what I am reading here.

 

[8trackmind]

Well, I finally got the progresive springs installed in the front. I used 20 weight Belray fork oil and a few drops of ATP AT205 rubber conditioner(NOT SNAKE OIL, great stuff) and no spacers. (I'm about 200lbs)

Way less dive, better tracking in the corners and a plush ride to boot. Worth every penny...I'm happy! :-D

 

[Hoomgar]

Well, I finally got the progresive springs installed in the front. I used 20 weight Belray fork oil and a few drops of ATP AT205 rubber conditioner(NOT SNAKE OIL, great stuff) and no spacers. (I'm about 200lbs)

Way less dive, better tracking in the corners and a plush ride to boot. Worth every penny...I'm happy! :-D

What did they run you Jeff?

 

[8trackmind]

What did they run you Jeff?

$65.30 from Bike Bandit.

 

[frosty5011]

Try reading through this....some good info here:

It won't let me direct link, so use the link below, click on "Seven - Eleven" link on the upper left side, then click the "Suspension For Dummies" graphic.

http://www.oldskoolsuzuki.info/index.htm?fastcat/library/library.shtml~main

 

[rustybronco]

One thing to note when you change the ride height you change the center of gravity height and the rake of the front forks, the angle change of the forks will slow or quicken the front steering not much change but still noticeable. front and rear spring rates need to be balanced for the riders weight (front to rear weight ratio) and then fine tuned with shock valve compression or rebound settings and or fluid weight.

 

[JHawkins]

I ordered my Ikons in January, have about 2000 miles or so on the now. They are such a remarkable improvement it is unreal.

I am 6'0" and about 300 - I contacted the manufacturer in Australia when I ordered and gave them info about Me, GF, driving style, etc, and they picked a spring rate for me.

When I drive alone I leave it on the lowest setting - never bottoms out, rides nice and smooth. The originals would bottom out with just me on it and no gear. If I forget to set it up a notch and the GF gets on it will occasionally bottom out on the lowest setting.

With just the GF on the back I initially tried it on the 3rd (highest) preload setting, but the ride was a bit jarring, so I settled in on the 2nd setting and it is perfect, no bottoming out at all. With her and luggage I will likely go with the top setting.

I have not been driving aggressively enough to really test out the dampening settings, I have it set on 2 (1 to 4 are the possibilities, 1 the lowest) and everything seems fine, but I will need some aggressive roads to put it to the test.

Next step is the fork springs!

 

[dpep]

Anyway, out bikes need more weight on the front end.
This describes Marks's feeling of the front end sliding. More weight bias will typically stop this feeling. This can be done a few ways.

One, lean forward during turns, get your weight forward.
Second, raise the rear end, think teeter totter, or a fulcrum.
More ride height in the rear will put more weight on the front, giving it a planted feel. This can be done by simply installing longer rear shocks.
Third, raise the fork tubes in the triple clamps. By lowering the front you have raised the rear. The problem with this is ground clearance, you've lost some by lowering the front.

One good way to move weigh bias forward is to install a frame mounted fairing. My 850 has a better feel for the curves with its Winjammer than it does without.

 

[Hoomgar]

Bump.

Anyone else have any tidbits of wisdom to share?

 

[koolaid_kid]

Just that Motorcycle Accessory Warehouse has the fork springs for $50 (Buy it Now) on eBay.

 

[Tom MLC]

Very interesting thread Mark. Comes back at a good time. There are several threads running right now with suspension issues, including my own. Perhaps that's why you bumped this one? Thanks.