Racetech Shock Spring

[chemicalsmile]

Has anyone replaced their rear shock spring with one from Racetech? When I did my front springs there wasn't anything available but as of today I see they have them (SESP 70225 series - might technically be an Eibach). I've looked into the Hyperpro option, just not sure how well their progressive spring would pair with the straight rate front springs.

Aside from the new front springs really highlighting the mushiness in the rear, I swear the rear sits lower now than it did so maybe the spring has taken a worse beating and I'd like to rectify that without dropping a bunch of coin on a whole new shock.

 

[msr1317]

Sorry by my english

I´m thinking that you can look at this


http://www.reactivesuspension.com/downloads/PENSKE_SPRING_APPLICATION_CHART.pdf


I hope help you
bye bye

 

[chemicalsmile]

Thank for the reply, although I believe those springs are only for the Penske replacement shocks. From everywhere I've checked, the shock spring on our bikes are 7" x 2.25". I ran across a thread on the fz6r forum where a member has installed a racetech shock spring:

Suspension Adjustment - Page 4 - Yamaha FZ6R Forums - International FZ6R / XJ6 Motorcycle Community Forum

I've PM'd him to get the details. If/when I install it I"ll be sure to update the thread.

 

[motojoe122]

There is a guy on ebay that will revalve the stock shock, its BMC Racing. Just type in FZ6 rear shock, I think he charges $200.

 

[msr1317]

Sorry by mi english
Thank you by information

More later that I have wrote you, I have seem the spring dimensión.
(Fz6 2006 Spring)
it is 7.25"x 2.25" whith serial=12.5Kg/mm or 700lbs/inch
The correct is looking for "HYPERCO"

Hyperco Performance Suspension Catalog

I weight 95 kg or 209lbs. Penske recomendit for my weight one spring=800lbs and racetech sprig=756 lbs
But I don't get the correct spring in the catalogue, I don´t understand well it

Can you look it, and comment

Thank you , I hope understand me

 

[msr1317]

I think that Hyperpro has sprig by FZ6

HYPERPRO-SP-YA06-SSB017
HYPERPRO-SP-YA06-SSB023 (30mm smaller)

The problem is that it is progresive, not lineal and I don´t know datas of this.

Do you know datos of it?

 

[chemicalsmile]

I heard back from Spunky on the FZ6R forum and apparently their shock setup as much different than ours however he used the RaceTech calculator to get the spring rate for his RaceTech spring and sounds like it worked out pretty well. He also said that he didn't have to buy different collars, apparently you only need to use them if you are getting a spring lighter than stock.

After some more looking around I'll probably end up going with Hypercoil - you can buy them from Traxxion Dynamics for $100 and give them your riding and weight information and they'll get you the right spring. That's actually a little cheaper than the catalogue you posted as it's listing them for $102.60. Save a couple bucks and have someone to blame if the spring is too light or hard? Sounds good to me

Of course, if you're in a different country it might be cheaper for you to order from the catalogue - looks like the part # would be 7A0700 where the 7 is the height in inches, the A is 2.25" ID and 0700 is the spring rate in lbs/inch (you could figure this out by using RaceTech's calculator HERE (top of page).

There are a few people here running Hyperpro spring setups and they all sound very pleased but they are progressive springs whereas RaceTech and Hypercoils are not. I have RaceTech fork springs out front and although they can be harsh on really rough roads, I like the predictability and want to match them with a linear shock spring to achieve 30mm sag on both ends.

 

[FinalImpact]

What's funny is the OEM rear is linear while the fronts are progressive. And now you find these aftermarket ones and they sell the progressive when a linear rate is what we desire.

Perhaps progressive is good for cruiser but I prefer linear as its more predictable.

Here is the info for the stock rear spring.

Spring rate K1 127.40 N/mm (727.45 lb/in) (12.99 kgf/mm)
Spring stroke K1 0.0–50.0 mm (0.00–1.97 in)
Optional spring available No
Enclosed gas/air pressure (STD) 1200 kPa (170.7 psi) (12.0 kgf/cm²)

msr1317, progressive means as the spring is compressed the rate increases. The linear springs the rate remains constant throughout the range of compression.

Look at the fronts to see an example:
Spring rate K1 7.40 N/mm (42.25 lb/in) (0.75 kgf/mm)
Spring rate K2 11.80 N/mm (67.38 lb/in) (1.20 kgf/mm)
Spring stroke K1 0.0–70.0 mm (0.00–2.76 in)
Spring stroke K2 70.0–130.0 mm (2.76–5.12 in)

Collar length 131.5 mm (5.18 in)
Installed length 347.0 mm (13.66 in)

The initial rate is K1 until compressed aprox 70mm and the rate progresses towards the value K2 (1.20kg/mm) as compressed. The problem is 0.75kg/mm is just too soft and the nose compresses to easily over average terrain and basic braking maneuvers.

 

[msr1317]

Thank for the reply,
Thanks to FinalImpact, chemicalsmile, and motojoe122,
As FinalImpact says, the linear spring is more predictable. But the option Hyperpro I think that it is good option.

1-Front sprig:
The fromt sprig Hyperpro is progressive, but this has nothing to do with the progressive original. They are the day and night, It is good option.
I think, the best option front sprig, is looks at a spring with K=0.8Kg, 0,85Kg Ohlins or Bitubo K=0,9Kg, o Racetech.

2- Rear spring:
In the first time, I did not know the measures of stock rear sprig, I saw

http://www.600riders.com/forum/fz6-mods/11735-shock-spring-rate.html

As FinalImpact says stock rear spring is 7.25"x 2.25" K= 700lbs/inch
And watching Racetech cataologo, I know that I need K=750lbs
Hyperpro is 7.25"x 2.25". It's just replace. It is a bit more strong that stock spring. I think that it good option. But Do you need think that the hydraulic part is not good it will be necessary a revalving (Change valve and new fluid hydraulic) in a future (This is a very noticeable difference) about 200$. But you're on the right track.
I have thought in a linear sprig, and I find

Hyperco: 7”x2.25”, K=750lbs/inch reference and price : 7A0750 81.00$

7A0700. It has the same K=700 than stock spring and 7”. It is not option.

Eybach: 7”x2.25”, K=750lbs/inch reference: New 0700.225.0750

The problem is the difference in measures 7.25”- 7”=0.25” is the difference in measures. We have to get a close spring To provide us with that measure. That is my problem to solve. How do I get it?
I hope I have explained and be helpful, I know my English is not very good. By the way I'm from Spain

 

[msr1317]

I do not know, I have not seen, but I've read on for people who have in the spring number 6 passes to four with only the change Hyperpro spring

 

[FinalImpact]

Thank for the reply,
Thanks to FinalImpact, chemicalsmile, and motojoe122,
As FinalImpact says, the linear spring is more predictable. But the option Hyperpro I think that it is good option.

1-Front sprig:
The fromt sprig Hyperpro is progressive, but this has nothing to do with the progressive original. They are the day and night, It is good option.
I think, the best option front sprig, is looks at a spring with K=0.8Kg, 0,85Kg Ohlins or Bitubo K=0,9Kg, o Racetech.

2- Rear spring:
In the first time, I did not know the measures of stock rear sprig, I saw

http://www.600riders.com/forum/fz6-mods/11735-shock-spring-rate.html

As FinalImpact says stock rear spring is 7.25"x 2.25" K= 700lbs/inch
And watching Racetech cataologo, I know that I need K=750lbs
Hyperpro is 7.25"x 2.25". It's just replace. It is a bit more strong that stock spring. I think that it good option. But Do you need think that the hydraulic part is not good it will be necessary a revalving (Change valve and new fluid hydraulic) in a future (This is a very noticeable difference) about 200$. But you're on the right track.
I have thought in a linear sprig, and I find

Hyperco: 7”x2.25”, K=750lbs/inch reference and price : 7A0750 81.00$

7A0700. It has the same K=700 than stock spring and 7”. It is not option.

Eybach: 7”x2.25”, K=750lbs/inch reference: New 0700.225.0750

The problem is the difference in measures 7.25”- 7”=0.25” is the difference in measures. We have to get a close spring To provide us with that measure. That is my problem to solve. How do I get it?
I hope I have explained and be helpful, I know my English is not very good. By the way I'm from Spain

The free height of a spring isn't always that critical but it can be depending on where its used.

If the installed height gives the force needed and it can compress without coil binging (coils stacking on each other) than it may work. So I wouldn't worry as much about the free height as long as it fits and works. 0.25" is not that big of a deal if the rate is correct for the application.

 

[msr1317]

If we do not supplement it. The spring let go out of the closure. It can be a disaster at high speed, is foolhardy.

 

[msr1317]

One solution may be to supplement the stem, before closing with washers worth 0.25 "or make a new closure as in a lathe. Or find a business closure of thickness 0.25" + current. I want to work in this last line.

 

[msr1317]

The free height of a spring isn't always that critical but it can be depending on where its used.

If the installed height gives the force needed and it can compress without coil binging (coils stacking on each other) than it may work. So I wouldn't worry as much about the free height as long as it fits and works. 0.25" is not that big of a deal if the rate is correct for the application.

I like to know your opion about this emulator for fork suspension.

43 MM Intiminator, fits 2004-2009 FZ6

Thank you

 

[FinalImpact]

I personally opted to go another route as I found R6 forks for very cheap and LOVE THEM! Best Money I ever spent on the bike!

They seem like they are turnable (43 MM Intiminator, fits 2004-2009 FZ6) if you don't mind taking it apart and those who have them appear to like them. Do a search and you will find comments about them. However - think the Racetech are more popular but the principal is the same.

Again - the free height of the spring being 0.25" different is nothing. The rear shock pre-load adjuster will easily take care of that.

If you have money to burn, spend it on the R6 forks and good after market Coil Over Shock and Spring vs machining a spacer!

 

[msr1317]

I personally opted to go another route as I found R6 forks for very cheap and LOVE THEM! Best Money I ever spent on the bike!

They seem like they are turnable (43 MM Intiminator, fits 2004-2009 FZ6) if you don't mind taking it apart and those who have them appear to like them. Do a search and you will find comments about them. However - think the Racetech are more popular but the principal is the same.

Again - the free height of the spring being 0.25" different is nothing. The rear shock pre-load adjuster will easily take care of that.

If you have money to burn, spend it on the R6 forks and good after market Coil Over Shock and Spring vs machining a spacer!

Thanks for your advice.

Anyway, think and brainstorm ideas do not cost money. I believe that knowledge is achieved by changing opinions, and reasoning, and evaluating the proposals.
I've found this link, is in Spanish, but the pictures are illustrative.

Info needed - Rear shock

I'm evaluating costs and maybe I decant a commercial solution for my basic Ohlis type rear shock (YA-403). This would again have control of rebound, and preload, the spring is 54 equivalent to 800lbs as recommended Penseke racing at their tables for my weight.

For the front suspension but I saw another solution at first seems expensive.
What strikes me is that it uses low-density oils, which seem comparterse best, not the solution that offers a 20w Racetech with 8 holes.

FG Special Parts - accessori per moto, ammortizzatori posteriori, ammortizzatori di sterzo, kit forcella, cavalletti di sollevamento, attrezzature per officine, pedane per moto, piastre forcella per moto, tendicatena per moto

Thank you very much for being so participative and provide ideas
A greeting from Spain.

 

[chemicalsmile]

Reviving this as I'm going to pull the trigger on this soon. I've got an email out to RaceTech regarding the length of the spring being a problem and whether or not going up another 100lbs/in will get me the sag I want.

According to bmccrary's thread when you've got the preload cranked to 7 you're actually increasing the spring rate by 262.5 lbs/in - if that's correct, then we're technically running 960 lbs/in at 7 preload? If so, I'm a bit worried about whether going up to an 800 lbs/in spring (what the RT calculator recommends) will get me the sag I need. I'm guessing I'll be using at least half the preload adjustment just to make up the .25" gap and since I'm currently getting 45mm sag with preload maxed I'm questioning whether or not I'll have enough left to get me close to 30mm.

I'll update when I hear back from RT.

 

[chemicalsmile]

So after further research I found that preload doesn't actually affect spring rate so that statement was incorrect.

Heard back from RaceTech this afternoon - they said the website calculator is incorrect and I'd actually need a 1400 lb/in spring... They also said they offer a 1/4" spacer to make up for the difference in spring length for another $20.

I emailed back asking, but I'm a little apprehensive about doubling the spring rate with no change in damping on the shock...seems like it would just pogo all the time.

 

[chemicalsmile]

RaceTech confirmed that the shock would need revalved to handle that large of a rate increase....

While searching I found an Eibach 7" x 2.25" 850 lb/in spring for $40 on ebay so I'm going to give that a try. If RT was right, I'm not going to get the correct sag I want but hopefully it'll get me a bit closer while not overwhelming the stock valving.

 

[FinalImpact]

Correct; how much you pre-load does not change the springs rate. Thats done by coil dia, heat treating, coil count and things like that.

So what are you trying to get that you don't have now?



You might look at this, but it opens a whole new can of worms.. .. ..
http://www.600riders.com/forum/fz6-general-discussion/36842-somethin-black-2.html#post511569