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Suspension Mods - On the cheap :)

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Old Dec 10, 2015 | 11:31 AM
  #31  
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Great year GSXR forks to use as the length is right, matches the stock fork length.

Did you use gsxr triples or cbr triples?

What offset?

James
Old Jan 14, 2016 | 07:51 PM
  #32  
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I'm happy to report I have the 1mm hole drilled in my cartridges (as recommended by Roger).

The local shop didn't have a 1mm bit, but they had a #61 bit, which was .0390 instead of .0394... Close enough

My USA made Milwaukee drills with Jacobs chucks wouldn't grip the tiny bit, nor would my Dremel... I had to borrow a friends Costco Kawasaki cordless drill to grip the bit LOL...

Also received my Silkolene PRO RSF 7.5wt fluid in the mail. It appears Silkolene discontinued the red label "Pro" RSF and is now only selling the blue label RSF... I managed to find a bottle of red label Pro RSF...

After drilling the hole i smoothed it off (top and bottom) with 320 grit sandpaper.

More to come...


James
Old Jan 15, 2016 | 07:17 AM
  #33  
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Originally Posted by thedeatons
I

My USA made Milwaukee drills with Jacobs chucks wouldn't grip the tiny bit, nor would my Dremel... I had to borrow a friends Costco Kawasaki cordless drill to grip the bit LOL...

James
What !? American ideology of 'Bigger is better' is not working ? LOL...
Old Jan 15, 2016 | 08:11 AM
  #34  
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Not so much an ideology as a system of kicking ***, taking names and just being all around awesome.
Old Jan 15, 2016 | 11:27 AM
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Originally Posted by VTR1000F
Not so much an ideology as a system of kicking ***, taking names and just being all around awesome.
I am profoundly disappointed by this.
Old Jan 15, 2016 | 01:58 PM
  #36  
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I would post that I am profoundly LOL if I used acronyms like LOL.
Old Jan 15, 2016 | 06:09 PM
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Next time i'll try my 1/2" USA made Milwaukee with Jacobs chuck...

James
Old Jan 15, 2016 | 06:18 PM
  #38  
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Next time, just drill a bigger hole. No doubt, that will be better.
Old Jan 15, 2016 | 06:37 PM
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Lol... Good one
Old Jan 16, 2016 | 02:20 PM
  #40  
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READ CAPS

Originally Posted by thedeatons
Let me start by saying i love this forum. Everyone here has been so helpful, and the knowledge of the owners here is truly amazing.

Rider info:
Age: 48 yrs old
Height: 5'11"
Weight: 155 not including gear
170 with gear
Type of riding: Fast street rider
GIVING VITAL STATISTICS FOR POSTERITY

I'm at a point where i don't have the money for the suspension upgrades i want to do, like my dream list... But i can probably do a few things in the late winter, after February, so i'm forming some ideas, and looking for thoughts from you guys...


PREFACE WHAT YOUR MODIFYING; I.E., OEM

HOW MANY ON VTR, FORKS, STEERING BEARINGS, WHEELS, ETC

AS OTHERS STATED, DON'T WORRY ABOUT IT IF NEVER CRASHED
Swingarm Angle


Rake and Trail (and wheel alignment)


Goal
My goal is to do a few simple "mods" to the stock suspension that are super cheap, but net some gains in performance. I'm not really the kind of guy who throws a lot of money at brand names and "recipes". Not that anything is wrong with that, I just like to gather knowledge and do the work myself. I definitely have more time available than money.

James
Originally Posted by thedeatons
Lol... Good stuff!

Yeah i've had Ohlins before, along with Custom Axis (same as Penske, but for quads), and i fully understand money buys suspension happiness... Unfortunately i no longer have an Ohlins/Axis budget
KIDS GOING TO / IN COLLEGE? LOL


I'll run some numbers on those VFR springs, thanks for those numbers.

I already have a 6mm shim between the frame and top of the rear shock, and rear shock is at its lightest preload setting.

Front forks are showing 6mm above the clip-ons, with unknown oil weight (until now i haven't messed with them, as they don't leak, and i was focusing on other things).
IS THAT 6MM BELOW SNAP-CLIP AND OEM CLIP-ONS ARE WHAT HEIGHT (25MM)?

Current swingarm angle is 10 degrees and i just tried bunping rear preload by two notches and found the angle didn't change (not on the instrument i was using anyway).

I may add more ride height to the rear just in the name of looking for a 12.5 degree swingarm angle... More on that later.

IS THIS STATUS B4 MODS?
Bike rides well, but i feel the turning characteristics could be better. Turn in feels fine. Not quick, but fine. Mid corner feels ok. Corner exit i run wide, which is why i'm first examining swingarm angle/anti squat. If i can achieve a couple more degrees of swingarm angle, then i will begin to understand how i like that number and what it does for turning on my particular bike...

James
Originally Posted by Cadbury64
+1

If you increase the spring preload at the shock, the ride height/swingarm angle should increase as the shock will sit higher in its stroke for any given load. If you were measuring this with the bike unladen on a stand you won't measure any change because the shock is already topped out.

If the preload is already appropriate for your weight, then you could look to adding more shim height to lengthen the shock, but that may start to get the lower chain run a bit close to the exhaust.
REAR RIDE HEIGHT EFFECTS TILT ANGLE ON SIDE STAND TOO

One other thing that may be affecting cornering feel is the tyre profile. Are they a bit worn, pressures OK etc?

If it was me, I'd be flushing and refilling the forks with some fresh oil before going too much further. No need to dismantle the seals to do this.
Originally Posted by thedeatons
Ok... it's been almost 24 hours, so time for an update

In the past 18 or so hours I've found some great information...

GOOD TO DOCUMENT BUT A VTR WEIGHTS 470# FULL OF FLUIDS

Race Tech forkspring rate recommendations:
Stock VTR: .585
Race tech recommends.822kg/mm FRSP S3534 series


Race Tech SpringRate Calculator settings I inputted:
-Street
-lbs
-155 my weight
-415 bike weight(semi wet) (Original Race Tech weight of bike was 435, I subtracted 20 lbs because of slips-ons, PAIR removal, lightened flywheel, stick coils, no toolkit, Sargent seat (with less foam))

Information from Manufacturers

Race Tech recommends .86

Ohlins only has an.86 spring available and doesn't have any reference as to preferred spring ratefor my weight because bike is pre 2005

Traxxion recommends(Hyperco springs) .95

GMD Computrackrecommends (K-Tech springs) .95

OEM Fork SpringRates (in kg/mm) of bikes that use FRSP S35 series springs:
Honda Superhawk OEM.585
95-99 Duc Monster900 .686
98-01 Honda Vfr800.74
04-05 Honda Hornetcb600f .75
95 Yamaha yzf600r.77
96 Yamaha yzf600r.80
01-05 Yamaha fz1 .80
99-07 Yamaha yzf600r.81
97-98 Yamaha yzf600r.81
00-01 Duc 996 sps.95


Today I ordered 1996 YamahaYZF600R fork springs (.77) for $15 shipped on Ebay!
CHEAP

Here are current percentages of what Race Tech recommends vs what I am going to have:

Front
.822 recommended
.77 have
93% of what RaceTech recommends I have

Rear
17.5 recommended
16.4 have
93% of what RaceTech recommends I have

YOU LIKE CRUNCHING NUMBERS BUT WHAT IS RECOMMENDED IS JUST AS YOU KNOW A STARTING POINT

So, this fork spring install of .77 will balance the front and rear to exactly 93% of what Race Tech recommends. No it's not exactly what they recommend, but it is far more balanced than what I have now, for very little money.

Furthermore, right now, with full gear on, I have exactly 23mm of sag in the rear. That is with the front OEM springs, the really soft ones. I'm planning to re-measure the sag after installing the stiffer fork springs... I'm betting it will be different

So, that being said, the stock rear spring, even though it is only 93% the value of what Race Tech recommends, seems appropriate for my weight. With this logic applied to the front forks, I should be fine with the 95 YZF600R fork springs I just picked up, as they are 93% of the value Race Tech recommends, just like the rear shock in stock form...

This winter I'll be taking the forks apart, changing out the fork oil, facing the stock valve bodies, and probably re-shimming the valve stack... Shouldn't cost too much... In fact I'm thinking I'll be into this for the $15 fork springs, cost of fork oil, and cost of a few shims... I may as well do the seals while I'm in there....

Anyway, feel free to use the information above to find some springs from another bike that work for your weight. I'm certain there are quite a few 996 SPS riders on the Ducati forums with stock springs laying around, if someone needs a .95 spring

1 INCH PVC IS GOOD IF STEEL WASHERS ISED TOP & BOTTOM

James
Originally Posted by Just_Nick
My low-budget mods:
2007 ~ 2007 GSX-R forks, wheel, brakes, triple clamp: $180
Riser clip-ons: $30
Custom size bearings and races from Allballs: $30 for upper and lower

$240 for better braking, better handling, and better looks. It's so nice to ditch the stock forks.
GOOD DEAL!

BALANCE IS THE KEY BETWEEN SUSPENSION, BRAKES AND RIDING STYLE

Last edited by skokievtr; Jan 16, 2016 at 02:34 PM.
Old Feb 8, 2016 | 10:18 PM
  #41  
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Originally Posted by thedeatons
Great year GSXR forks to use as the length is right, matches the stock fork length.

Did you use gsxr triples or cbr triples?

What offset?

James
Sorry for the late response. I used the stock GSX-R triple clamps, which have an off-set of 30mm. However, the top triple has an offset mount for the ignition which doesn't look good, so I am looking at the 954 top clamp to replace it.
Old Apr 3, 2016 | 04:31 PM
  #42  
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James,
Do have any update info to add?
Suzuki 3 port valves? Shim stack specs? Etc.?
Very interested in hearing more on your inexpensive suspension upgrades. :^)
Old Apr 3, 2016 | 04:42 PM
  #43  
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I ended up going with Roger's fork modifications and left the shim stack alone. I didn't end up using different valving from stock. I did however rebuild forks with fresh 7.5 WT fork oil, new seals, and the straight rate Springs I mentioned earlier. Feels very solid, very planted now, Although I haven't had a chance to really rip on it yet this year. Hopefully in the next month I will have an update as to how it feels in hard corners.

For my limited riding this set up will probably be perfect, and I probably won't even upgrade the rear shock, as it is hard for me to justify spending that much money on a rear shock when I ride so little anymore.

James
Old Apr 3, 2016 | 06:03 PM
  #44  
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Thanks for the update, James.
I've changed springs as well, ('97 yzf600), new seals and 7wt oil. Haven't been able to dig in any further yet as I ride my SH as daily transportation.
Old Apr 3, 2016 | 07:24 PM
  #45  
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Good to see my spring recommendation help save someone some money :-)
Old Apr 3, 2016 | 10:46 PM
  #46  
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Originally Posted by thedeatons
Good to see my spring recommendation help save someone some money :-)
Old Apr 29, 2025 | 06:50 AM
  #47  
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Originally Posted by thedeatons
Ok... it's been almost 24 hours, so time for an update

In the past 18 or so hours I've found some great information...


Race Tech forkspring rate recommendations:
Stock VTR: .585
Race tech recommends.822kg/mm FRSP S3534 series


Race Tech SpringRate Calculator settings I inputted:
-Street
-lbs
-155 my weight
-415 bike weight(semi wet) (Original Race Tech weight of bike was 435, I subtracted 20 lbs because of slips-ons, PAIR removal, lightened flywheel, stick coils, no toolkit, Sargent seat (with less foam))



Information from Manufacturers

Race Tech recommends .86

Ohlins only has an.86 spring available and doesn't have any reference as to preferred spring ratefor my weight because bike is pre 2005

Traxxion recommends(Hyperco springs) .95

GMD Computrackrecommends (K-Tech springs) .95



OEM Fork SpringRates (in kg/mm) of bikes that use FRSP S35 series springs:
Honda Superhawk OEM.585
95-99 Duc Monster900 .686
98-01 Honda Vfr800.74
04-05 Honda Hornetcb600f .75
95 Yamaha yzf600r.77
96 Yamaha yzf600r.80
01-05 Yamaha fz1 .80
99-07 Yamaha yzf600r.81
97-98 Yamaha yzf600r.81
00-01 Duc 996 sps.95



Today I ordered 1996 YamahaYZF600R fork springs (.77) for $15 shipped on Ebay!

Here are current percentages of what Race Tech recommends vs what I am going to have:

Front
.822 recommended
.77 have
93% of what RaceTech recommends I have

Rear
17.5 recommended
16.4 have
93% of what RaceTech recommends I have


So, this fork spring install of .77 will balance the front and rear to exactly 93% of what Race Tech recommends. No it's not exactly what they recommend, but it is far more balanced than what I have now, for very little money.

Furthermore, right now, with full gear on, I have exactly 23mm of sag in the rear. That is with the front OEM springs, the really soft ones. I'm planning to re-measure the sag after installing the stiffer fork springs... I'm betting it will be different

So, that being said, the stock rear spring, even though it is only 93% the value of what Race Tech recommends, seems appropriate for my weight. With this logic applied to the front forks, I should be fine with the 95 YZF600R fork springs I just picked up, as they are 93% of the value Race Tech recommends, just like the rear shock in stock form...

This winter I'll be taking the forks apart, changing out the fork oil, facing the stock valve bodies, and probably re-shimming the valve stack... Shouldn't cost too much... In fact I'm thinking I'll be into this for the $15 fork springs, cost of fork oil, and cost of a few shims... I may as well do the seals while I'm in there....

Anyway, feel free to use the information above to find some springs from another bike that work for your weight. I'm certain there are quite a few 996 SPS riders on the Ducati forums with stock springs laying around, if someone needs a .95 spring

James

I realize this is an old post and has lots of valuable info in it. I was following it blindly so this is on me. I bought a set of 03 FZ1 springs to swap into my bike. They are not 41mm forks, they are 43mm. Hopefully save someone the frustration down the road. The springs will not fit.
Old Apr 29, 2025 | 07:39 AM
  #48  
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Sorry... I think I remember pulling that information from Race Tech's website... might check the FZ1 build specs by year, they may have changed the fork size over time, or Race Tech could have mis-listed that bike model...
Old Apr 29, 2025 | 07:50 AM
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Originally Posted by thedeatons
Sorry... I think I remember pulling that information from Race Tech's website... might check the FZ1 build specs by year, they may have changed the fork size over time, or Race Tech could have mis-listed that bike model...
All good man. I should've looked it up to check. Have a set of Race techs on the way. With shipping to Canada and exchange buying used off eBay is half of what Race tech springs are.

I went with 1.00kg springs as I've converted my bike into a pseudo adv bike as well.

Last edited by Zacko; Apr 30, 2025 at 08:11 AM.
Old Apr 30, 2025 | 08:09 AM
  #50  
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The 01-05 FZ1 all had the same 43mm fork.
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