Jump to content
norwest

Stock FZ-07 Shock Breakdown

Recommended Posts

norwest
I had read a thread here that a member had mentioned that a FZ-07 stock shock can be disassembled, Well here is the proof.
 
The shock is an IFP (Internal Floating Piston) design same as the FZ-09 and probably the FJ-09 and separates the fluid and the nitrogen using a floating piston. The stock spring rate measured out at 11.1 kg/mm and checking it is a linear rate and not a progressive rate. With the preload adjuster backed all the way off you would have 10mm preload and you can crank it up to 17mm preload max.
 
I was pleasantly surprised that the valve itself seemed to have a good port flow area on both compression and rebound. Stock shim stacks are listed below.
 
Compression:
(7) 34x.15
17x.68 (Clamp)
37x3.18 (Base Washer)
 
Rebound:
(9) 30x.15
17x.68 (Clamp)
26x1.98 (Base Washer)
 
Bleed:
.86mm
 
With the stock shim stacks there is definitely room for improvement.
 
Anyway on to the images so you can see what is inside your shock assuming of course you are still running the stock shock.
 
Stock Shock:
fz07%20stock%20shock.jpg
 
Disassembled Stock Shock:
fz07%20stock%20shock%20disassembled.jpg
 
Stock Rebound Valve & Valving:
fz07%20stock%20shock%20rebound%20valving.jpg
 
Stock Compression Valve & Valving:
fz07%20stock%20shock%20compression%20valving.jpg
 
Terry
 
  • Like 4

Share this post


Link to post
Share on other sites
etorty
...unfortunately, I can't see any image...
 
In my most recent posts, I've used Imgur.com, and it works... at least for me.
 
Anyway...
When mounted, the shock have 7 mm of variation between the position "1" (the less preload possible) and the position "9" (max preload).
So, we have 8 steps, with 7 mm available: 0,875 mm every step, if I'm right...
 
I hope I can see the images, tomorrow...
 
Thank you, @norwest!  :)

www.MT-Series.it
Yamaha Official MT-Series Club

Share this post


Link to post
Share on other sites
norwest
Hmmm that is odd as I am looking at them in the post. Let me know if they don't show later for you.
 
Terry

Share this post


Link to post
Share on other sites
norwest
I can see them. But the second one I'd love to see at higher resolution (I'm old). :)
Yeah I am not what one would call a spring chicken either. The larger image should be showing up in a bit. 
Terry
 

Share this post


Link to post
Share on other sites
mike9999
I'm gonna ask the obvious question...is it possible to improve the stock shock?

Share this post


Link to post
Share on other sites
norwest
I'm gonna ask the obvious question...is it possible to improve the stock shock?
IMO yes it is but there are limitations as obviously if you want full adjustment then you should look for an aftermarket shock. As stated the stock valve has some decent ports IMO and the issue is the shim stacks.  
Terry
 

Share this post


Link to post
Share on other sites
twotone
Well yeah
 
If you can see all the guts you can fix em
 
Those shims are linear and safe package
But by no means progressive
Maybe bigger comp ports?
 
Nice work norwest
This will help kick start some DIYs

Share this post


Link to post
Share on other sites
gregjet
Northwest , you are a little beautie!
So the biggest problem is the spring rate being being basically matress foam rate.
The problem is if you put a heavier spring rateon this damping, is it going to become a serious pogo stick. So a valving change with a proper rate spring could be a viable upgrade provided you have a means of re pressurizing the de Carbon piston chamber.
I shall follow any posts on this thread closely ,even though I am running a nitron. A set of aluminium hardware would be a nice upgrade if you could get the shock working. It would be of interest to anyone in Australia who wants to race the MT07 ( LAMS one, as the full version is too big a capacity) in Formula 3. All the things required to make it competitive are within the rules EXCEPT the shock externals MUST remain stock . Internals and spring and spring hardware may be changed. Yes it's a stupid rule and I tried on several occasions to get it changed but to no avail.
 

Go forth and modify my son...go forth and modify...

Share this post


Link to post
Share on other sites
norwest
Those shims are linear and safe package But by no means progressive
Maybe bigger comp ports?
 
Nice work norwest
This will help kick start some DIYs
What do you mean the shims are linear? 
Comp ports have good flow and a decent shim area so IMO that should not be an issue.
 
Thanks!!
 
Terry
 

Nov 4, 2015 14:33:09 GMT -8 gregjet said: Northwest , you are a little beautie!
So the biggest problem is the spring rate being being basically matress foam rate.
The problem is if you put a heavier spring rateon this damping, is it going to become a serious pogo stick. So a valving change with a proper rate spring could be a viable upgrade provided you have a means of re pressurizing the de Carbon piston chamber.
I shall follow any posts on this thread closely ,even though I am running a nitron. A set of aluminium hardware would be a nice upgrade if you could get the shock working. It would be of interest to anyone in Australia who wants to race the MT07 ( LAMS one, as the full version is too big a capacity) in Formula 3. All the things required to make it competitive are within the rules EXCEPT the shock externals MUST remain stock . Internals and spring and spring hardware may be changed. Yes it's a stupid rule and I tried on several occasions to get it changed but to no avail.
You must have bad vision, Never been referred to as a little beautie.  :)
 
I would be curious to hear from someone in the 180 lb range and have them check their sag and let us know what ramp the preload adjuster is on as well as free sag and race (rider) sag. The 11.1 kg/mm spring is a higher rate then alot of other shocks out there so I am just a bit curious where we are at with the numbers.
 
Yes the rebound would not be able to control a higher rate spring, What I am guessing just by looking at the port, stack, bleed is it is initially slow on rebound but once the stack opens up it is pogo stick time then it ramps up on a progressive ramp. IMO the stock valving is too light even for the stock spring rate.
 
We have that same rule here for some vintage classes.
 
Terry
 
 

Share this post


Link to post
Share on other sites
gremlin
Those shims are linear and safe package But by no means progressive
Maybe bigger comp ports?
 
Nice work norwest
This will help kick start some DIYs
What do you mean the shims are linear? 
Comp ports have good flow and a decent shim area so IMO that should not be an issue.
 
Thanks!!
 
Terry
 

Nov 4, 2015 14:33:09 GMT -8 gregjet said: Northwest , you are a little beautie!
So the biggest problem is the spring rate being being basically matress foam rate.
The problem is if you put a heavier spring rateon this damping, is it going to become a serious pogo stick. So a valving change with a proper rate spring could be a viable upgrade provided you have a means of re pressurizing the de Carbon piston chamber.
I shall follow any posts on this thread closely ,even though I am running a nitron. A set of aluminium hardware would be a nice upgrade if you could get the shock working. It would be of interest to anyone in Australia who wants to race the MT07 ( LAMS one, as the full version is too big a capacity) in Formula 3. All the things required to make it competitive are within the rules EXCEPT the shock externals MUST remain stock . Internals and spring and spring hardware may be changed. Yes it's a stupid rule and I tried on several occasions to get it changed but to no avail.
You must have bad vision, Never been referred to as a little beautie.  :) 
I would be curious to hear from someone in the 180 lb range and have them check their sag and let us know what ramp the preload adjuster is on as well as free sag and race (rider) sag. The 11.1 kg/mm spring is a higher rate then alot of other shocks out there so I am just a bit curious where we are at with the numbers.
 
Yes the rebound would not be able to control a higher rate spring, What I am guessing just by looking at the port, stack, bleed is it is initially slow on rebound but once the stack opens up it is pogo stick time then it ramps up on a progressive ramp. IMO the stock valving is too light even for the stock spring rate.
 
We have that same rule here for some vintage classes.
 
Terry
 

 
 
 
I'll check my sag. I'm 145lbs maybe 155lb with gear. I'll repost my numbers once I can have my buddy help. Thanks for sharing this

Share this post


Link to post
Share on other sites
gregjet
I am 188lbs. The stock shock was on 3rd easiest cam setting before I went to aftermarket shock.. That was for sag of about 15mm ( wheel) unloaded. With rider it would just drop way too far considering only 130mm travel total. Set it up for rider sag and it was harsh as hell then of course would blow through it's travel when you hit a big bump ( of which we are amply endowed). Typical preload blues handling.
Shock travel to wheel travel is a 2.36:1 lever ratio. With only 130mm total travel and 2.36 ratio I am thinking it should be a fair bit stiffer than 11, But I set my shocks up with a rate that will allow me min preload to get bike loaded only sag. It prefer more compliant initial travel.

Go forth and modify my son...go forth and modify...

Share this post


Link to post
Share on other sites
twotone
Norwest,
 
Linear as in stack of one size shims
 
Progressive and better control might look like this
 
4x .15x 40 mm
2x .2 X 38
.2x 36
.2x 32
.2x 28
.2x .24
4x .2x 22
.2x 30
From GSXR 750 comp

Share this post


Link to post
Share on other sites
etorty
Hmmm that is odd as I am looking at them in the post. Let me know if they don't show later for you. 
Terry
This is really odd...
I can't see any image even now. I use a Mac with OS X (10.11.1) and Safari.
In the place of the images, I see a little square with an "?" in the middle.
I've checked also with my cell phone (a Samsung with Android) and Firefox, nothing.
 
I can see images in other posts... I don't understand why I can't see your images...  :-[

www.MT-Series.it
Yamaha Official MT-Series Club

Share this post


Link to post
Share on other sites
norwest
Norwest, 
Linear as in stack of one size shims
 
Progressive and better control might look like this
 
4x .15x 40 mm
2x .2 X 38
.2x 36
.2x 32
.2x 28
.2x .24
4x .2x 22
.2x 30
From GSXR 750 comp
Back when I was taking the suspension seminar at Race Tech that same exact question was asked pertaining to straight vs tapered stacks the tapered being progressive vs the straight being linear. Paul Thede's explanation was this  

"Contrary to popular belief the tapered stack is not progressive. It's advantage is that it has multiple bending axes that assist in smoothing the abrupt bend of a straight stack thereby resisting permanent distortion (creasing). It also created more clearance from the baseplate."
Would have been nice to see a dyno graph with both stack arrangements.
 
Just for kicks and grins I ran a FEA on two stacks (1) Straight & (1) Tapered, Shims shown below and this is the resulting image from it. Both stacks used the same valve.
 
Tapered Stack:
34x 0.2
33x 0.2
32x 0.2
31x 0.2
30x 0.2
29x 0.2
28x 0.2
27x 0.2
26x 0.2
25x 0.2
24x 0.2
23x 0.2
22x 0.2
21x 0.2
20x 0.2
 
Straight Stack:
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
34x 0.2
20x 0.2
 
tapered%20vs%20straight.png
 
As you can see the straight stack is slightly stiffer but is not progressive in nature.
 
Terry
 

Share this post


Link to post
Share on other sites
norwest
I am 188lbs. The stock shock was on 3rd easiest cam setting before I went to aftermarket shock.. That was for sag of about 15mm ( wheel) unloaded. With rider it would just drop way too far considering only 130mm travel total. Set it up for rider sag and it was harsh as hell then of course would blow through it's travel when you hit a big bump ( of which we are amply endowed). Typical preload blues handling. Shock travel to wheel travel is a 2.36:1 lever ratio. With only 130mm total travel and 2.36 ratio I am thinking it should be a fair bit stiffer than 11, But I set my shocks up with a rate that will allow me min preload to get bike loaded only sag. It prefer more compliant initial travel.
Hmmm that is not really a high leverage ratio, The one thing I did notice on the valve was the very small bleed considering it does not have a rebound adjuster (Rebound adjuster affects compression as well), That could lead to initial harshness.  I am calculating that the baseline rider sag should be right about 43mm and the free sag should have been right around 5-10mm with a preload of right about 8mm. Obviously we are not going to get 8mm preload on a stock shock using stock spring and adjuster. But I get where you are going as a stiffer rate spring with less preload will be softer initially then a softer rate spring with more preload both given the same rider sag number. 
Image showing computation in regards to higher rate spring with less preload is softer initially then lower rate spring with more preload. This is not a FZ-07 graph.
 
rate%20vs%20preload.png
 
Terry 
 

Share this post


Link to post
Share on other sites
norwest
Hmmm that is odd as I am looking at them in the post. Let me know if they don't show later for you. 
Terry
This is really odd... I can't see any image even now. I use a Mac with OS X (10.11.1) and Safari.
In the place of the images, I see a little square with an "?" in the middle.
I've checked also with my cell phone (a Samsung with Android) and Firefox, nothing.
 
I can see images in other posts... I don't understand why I can't see your images...  :-[
Hmmm i don't know why they would not be showing up for you. Worst case scenario shoot me a PM with your email address and I will send the images. 
Terry
 

Share this post


Link to post
Share on other sites
pattonme
@Norwest, can you get me detailed measurements of the orifices so I can model the piston? need diameter, distance from center for inner edge, length of arc at outer edge, width of 'lip', 'height' of orifice.
 
To get a better rebound stack, you'd likely want to preload the shims so that initial (up to say 50in/sec) has a much steeper curve and then tapers off.
 
 

Share this post


Link to post
Share on other sites
norwest
@norwest, can you get me detailed measurements of the orifices so I can model the piston? need diameter, distance from center for inner edge, length of arc at outer edge, width of 'lip', 'height' of orifice. 
To get a better rebound stack, you'd likely want to preload the shims so that initial (up to say 50in/sec) has a much steeper curve and then tapers off.
 

Compression: seat 1.13
r port 9.34
d port 6.44
w port 9.89
n port 4
d rod 14
d valve 40
 
Rebound:
seat 1.44
r port 9.37
d port 4.50
w port 5.92
d thrt 4.55
n thrt 4
d rod 14
d valve 40
 
Don't know how much steeper you want but it is already pretty steep.
 
Compression:
fz07%20stock%20compression.png
Rebound:
fz07%20stock%20rebound.png
Terry
 

Share this post


Link to post
Share on other sites
gregjet
I have found that setting up with stiffer spring and lower preload gives a much smoother transition into AND out of the initial end of the travel. Helps to control chatter and rear wheel skipping under brakes. The effective hysteresis curve can be clearly seen in your graph on the soft/hi preload. As tyres also have a similar but almost always different point in the travel you end up with additive and subtractive effects that make for some pretty unsettling behaviour at the initial travel area.
I would really like to check what spring rate I would prefer, but my Tony Foale software won't play anymore since I bricked by last SSD. What ever it actually is it is definitely higher rate than the stock one. Have you actually measured the spring rate? They may be incorrectly rated ( wouldn't be the first time).

Go forth and modify my son...go forth and modify...

Share this post


Link to post
Share on other sites
norwest
Ok so what did I do to make the shock rebuildable?
 
Installed a nitrogen bolt in the cap of the body. At this time it is holding 250 psi with no leaks. From this point forward you would have a shock that is rebuildable/revalvable by any reputable suspension shop. You are going to need the nitrogen needle to pressurize the shock with this setup.
 
Nitrogen bolt in cap:
fz07%20nitrogen%20bolt.jpg
 
Pressurized cap: I just use this to make it easier to block the end and charge the shock with nitrogen to check for leaks.
fz07%20pressure%20cap.jpg
 
Terry
 
 

Share this post


Link to post
Share on other sites
norwest
I have found that setting up with stiffer spring and lower preload gives a much smoother transition into AND out of the initial end of the travel. Helps to control chatter and rear wheel skipping under brakes. The effective hysteresis curve can be clearly seen in your graph on the soft/hi preload. As tyres also have a similar but almost always different point in the travel you end up with additive and subtractive effects that make for some pretty unsettling behaviour at the initial travel area. I would really like to check what spring rate I would prefer, but my Tony Foale software won't play anymore since I bricked by last SSD. What ever it actually is it is definitely higher rate than the stock one. Have you actually measured the spring rate? They may be incorrectly rated ( wouldn't be the first time).
Yes I have the Intercomp spring rate tester. I never believe any spec sheet numbers as they all vary. 
Terry
 

Share this post


Link to post
Share on other sites
gregjet
Thanks Terry, Good to know we have a real value.
I had huge problems setting up a DRZ400SM because the factory rateing was NOT what it said it was. Ended up having to buy 3 springs until I got the right rate.

Go forth and modify my son...go forth and modify...

Share this post


Link to post
Share on other sites
norwest
Thanks Terry, Good to know we have a real value. I had huge problems setting up a DRZ400SM because the factory rateing was NOT what it said it was. Ended up having to buy 3 springs until I got the right rate.
Just in case you want to see the data on the stock spring. 
Measured the spring at 10mm intervals while clearing the load to check for progressiveness and here are those numbers. I would say it is a linear rate spring.
 
10-110.5
20-110.0
30-110.0
fz07%20stock%20spring.png
 
Interesting note: Ohlins recommends a 115 N/mm (11.7 kg/mm , 656 Lbs in) spring rate for a 190 lb rider with gear. So it seems that the stock spring would be good for roughly a 180 lb rider with gear according to their recommendation.
 
Terry
 

Share this post


Link to post
Share on other sites
gregjet
Is the Ohlins shock the same stroke? Still 11.7 is better than 11.35 avg. My Nitron has a 650lbinch on it and seems not to bad actually. I wonder if there is a wide variation in spring rate fitted. My springs were definitely way too soft. Just checked and there is nothing on the stock springs. Maybe softer springs for the LAMS model? I did do a Foale calc but checked everything and didn't write it down anywhere, damm it.

Go forth and modify my son...go forth and modify...

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×

Important Information

By using this site, you agree to our Terms of Use.