Bilstein Shocks Info

[transio]

Ok, so I've been on the phone with Bilstein for the last two days due to a mixup in some shocks that I got from a Bilstein reseller.

Here's the deal. For the VehiCross, Bilstein suggests the following setup:

Front: B46-1738-H2
Rear: B46-1739-H1

However, I was accidentally shipped 1738-H1's for the front. The length and travel is exactly the same on the H1 and H2, however, the H1 has a more aggressive valving, making it about 25% stiffer than the suggested H2.

This is great news for those of us looking for a stiffer ride for better performance! The H1's are about $20 more per shock than the H2's, but they should provide a much closer-to-stock ride! Here's what I am going to install:

Front: B46-1738-H1
Rear: B46-1739-H1

I'll let you all know how it all works out. :D

[Dallas4u]

Good info Steve. Definitely let us know how the stiffer Bilstein's compare to the OEM ride. I think many of us would like to keep as close to the stock stiffness as possible if we have to purchase new shocks at some point.

[t2p]

transio:

Sounds good ......
.
I would definitely go with the H1 in the front ......... more so than the rear if I had to choose ..................
.
the front - probably due to the weight of the engine, etc ....... appears to require the additional damping .........

[joe-yamma]

transio, thanks for the info... please keep us posted.

i will be replacing the shocks on my Vx as soon as i can (read: afford it) and bilstein's are one of my choices.

[t2p]

JY:
.
We should get together so you can try my VX with the KYB MonoMax's.
.
I like the MonoMax's ........ but I don't really have any 'baseline' to offer a comparison ..............
.
I would like to try a VX with the Rancho 9000's set at the stiff settings .......... and also would like to try a VX with Billsteins ........
.
I was tempted to go with the 9000's ...... heard good things ....... but could not get the 'Monroe' out of my head .........

[joe-yamma]

t2p, we definitely need to get together.
you can feel the "see-saw bouncy yo-yo effect" in my VX :D

[transio]

Ok, I finally had a chance to get the Bilsteins on. And the verdict is... The ride is absolutely FANTASTIC !! The VX feels like a BMW M5 with them on. Very little roll, very good road feedback. If you're going for street performance, these are definitely the way to go. I haven't had a chance to test them out on rougher terrain yet, but I'll update you guys once I do. Again, the setup is:

Front: 1738-H1
Rear: 1739-H1

H1's are about 25-30% stiffer than H2's up front.

While changing out the rear shocks, I had a little bit of a revelation. I was looking at the extreme angle of attack that they are mounted at, and thought that this could very well be the reason they go so quickly. They're mounted at an angle about 30 degrees off vertical. This means that they endure about 150% of the load that they would if they were mounted vertically. I don't really see why Isuzu set them up the way they did (they're not even mounted directly to the frame rails). Anyhow, food for thought.

[thedutchguy]

how much did you pay for these shocks?

[angrylittleman]

http://www.eshocks.com/bil_veh.asp?Model_Index=237&Make=Isuzu&Group1=Trucks&Make_Long=Isuzu&Manf=All

[thedutchguy]

they're $200.00 alround at shox.com

[transio]

They cost me about $280 + shipping for all 4.

The 1738-H1's cost about $20 more per shock than the 1738-H2's

IMO, it's worth the extra $$$, though!

[transio]

Originally posted by thedutchguy
they're $200.00 alround at shox.com
Those are not the same shocks.

[t2p]

While changing out the rear shocks, I had a little bit of a revelation. I was looking at the extreme angle of attack that they are mounted at, and thought that this could very well be the reason they go so quickly. They're mounted at an angle about 30 degrees off vertical. This means that they endure about 150% of the load that they would if they were mounted vertically. I don't really see why Isuzu set them up the way they did (they're not even mounted directly to the frame rails). Anyhow, food for thought
.
??? .......... shock absorbers are sometimes mounted in a 'canted' position to allow for more suspension 'travel' ...... given the length and 'movement' of the shock absorber ........ this allows for more suspension movement given the movement at the shock absorber ........ just a guess .......

[transio]

Originally posted by t2p
.this allows for more suspension movement given the movement at the shock absorber I understand, but at the same time, applying the load at an angle multiplies the load to the shock absorber, because of basic trigonometry. If it's "canted" at a 45° angle (off vertical) for example, the load is approximately 141% what it would be if it were vertically mounted. The formula is something like this:

L = 1/cos(A) * F

Where A is the angle the shock is mounted at, F is the force applied to the wheel hub from the road, and L is the resultant load applied to the shock absorber.

At angle (A) = 0° your load (L) equals the force (F) applied to the wheel. As A approaches 90° your load (L) approaches infinity.

At 30° (like the VX is mounted at) the load (L) is something like 115% the force (F). If the suspension compresses a few inches, the shocks are canted even more, and could likely be enduring a load of 150% or more of the force applied to the hub, which is already significant to have compressed the suspension that much. I may be wrong, but I believe the load on the shocks increases exponentially as they are compressed.

This would explain why my rear shocks were leaking BADLY and my fronts were 100% fine when I replaced them all. Or am I missing something?

[SlowPro48]

Originally posted by transio

Or am I missing something?

Could be...

I'm no expert but it seems like all that load/vector/cosine stuff is for force transferred by solid rods, beams, etc.

The shock is not solid unless it's bottomed out, therefore the "load" experienced by the shock in most cases is limited to whatever damping force it's providing at the moment. The shock doesn't care if it's straight up or canted - all it cares about is squishing oil through that orifice. Thick oil and small opening at high speed? Lotsa damping going on. Shock feels high load. Old oil, thin and cut up from too many passes through the hole? Not much damping force there my friend. And of course no oil = no damping = no load. (other than friction)

I don't know if the VX shock's compression damping is position sensitive (fixed orifice, a nasty velocity squared situation) or is speed sensitive with shim stacks or something of that ilk - but either way you'll have to bust out a lot more complicated math to figure out the loads involved...

[t2p]

.
???
.
I think I'm going to get a headache ......
.
my two fronts (shock absorbers) were totally gone ........
.
one rear was totally gone - and the other rear was 75% or so gone ............
.
I installed KYB Monomax at all four corners ....... work very well - but I do not have anything to use in comparision .......

[transio]

Originally posted by SlowPro48
Could be...

I'm no expert but it seems like all that load/vector/cosine stuff is for force transferred by solid rods, beams, etc. Ok, there's definitely a difference between static and dynamic physics, but the load applied to the shock occurs at the point of attachment. That means that whatever happens inside doesn't matter.

It's been a long time since I've even looked at engineering or physics, but here's the low down, as I recall it:

In a triangulated system, a load applied at any point is translated across the adjoining members, creating either a force of tension or compression, depending on the direction of the force. In the case of the vehicross, you get something like the diagram below:

http://www.stevenmoseley.com/vehicross/shocks-diagram-1.gif

As you can see, when the shocks are compressed, the canter is increased. To explain why this makes a difference, here's a simple force diagram:

http://www.stevenmoseley.com/vehicross/shocks-diagram-2.gif

The shocks are in compression, with a pin joint at either end. The vertical force gets translated along the axis of the shock absorber, which then pushes back with a vertical AND horizontal load. The horizontal load gets absorbed by the wheel's mounting bracket (and whatever assembly that is attached to). Because the shock absorber is at an angle, it has to handle not only the vertical load applied by the road, but the horizontal loads created by the fact that it's angled. Essentially, it makes the shock work harder than it would in a vertical mounting position.

Additionally, it's not making the shock travel less. That's a misconception. The shock actually has to travel MORE for the same amount of wheel travel. Other negatives: the shock is applying unnecesary loads to other systems in your vehicle, and it's not mounted to your frame rails, but to the body.

I don't see one benefit to having the shocks mounted this way.

[SGT.BATGUANO]

I do.

As was mentioned before, better articulation. This is due to the fact that if you mounted a shock vertical, it would have to be much shorter and would limit rear suspension travel.

The top forward canting probably helps dampen motion with respect to the movement angle of the 4-link arms.

Also, the top of the shock IS mounted to the frame......via a stamped, welded bracket, NOT to the body.

The springs are handling the majority of the load forces, all the shocks have to do is dampen spring oscillation.

I really can't remember seeing a shock mounted perfectly vertical, maybe these are some reasons for this.

[transio]

Ok, points taken. I didn't see the bracket extension from the frame, but then, I wasn't looking too closely at the time. This was all more of an afterthought.

One more question: if the shocks are extremely stiff in compression, don't they absorb more of the initial impact of the load applied to the suspension than in softer shocks?

[SGT.BATGUANO]

Yes, I'd agree that they do. I don't know the compression/ rebound percentages (ratio,valving) for our shocks. Are they 50/50? I don't know. Someone here said they sent one to an aftermarkter to disect and find what the valving was. Probably should've asked them to find the weak link leading to premature failures, too.

[skunkworks]

Mine has been getting very skiddish in the rear on bumps lately. I got down to see if the shocks were leaking before they got out of warranty, and there is barely any clearance between the rebound bumpers and the frame. So it looks like basically I am bouncing around on the bumpers. Has anyone shortened the bumpers to see if it improves the ride and control. I would rather stiffen the sway bars than use the bumpers to control body roll.

albert
________
Suzuki Katana (http://www.cyclechaos.com/wiki/Suzuki_Katana)

[angrylittleman]

are the shocks covered under the basic warranty, or are they considered maintainence items, like spark plugs, brake pads, etc?

[transio]

If the shocks leak, they'll be covered.

[Reg Hinnant]

Hi Guy's
I thought I would give an update on Doetsch shock adventure.
HotSauce sent a pair of original shocks to them for disassembly to see if they could produce an equivalent replacement.
The only comment from them was that the oil orifice (into the reservoir) was very small and they had 3 times the shim stacks as normal. No comments on valve ratio's.
To make a long story short, I received a call from the owner stating that they did not think we would be happy with what they could provide.
So I'm going to add that to our original listing.
And I will add the comments about the new Bilstein numbers being a possible good combination.
It's interesting what the engineers came up with, for the shock design on this vehicle. :confused:

skunkworks, some have slit the 1st bumper to make it have less effect on handling.

[Denee]

I'm knew to the VX and probably will be asking quetions off and on. My question at the moment is about the rear suspension. It is rather stiff (like going over speed bumps and the rear takes it rather hard). Is there a way to "soften" the rear suspension so my rear passengers (which are few) wouldn't be jarred so much? If not, I can live with it.
thanks,
anocsunamoon@aol.com
Denee'

[transio]

You can just get some softer shocks. Probably for $100 installed, you can soften up the ride quite a bit. If you desire a "cadillac" ride, you'll have to get different springs, too. The downside is that your performance will be equally lessened. You'll have significantly more body roll. This would only cause problems if you drive your VX at high speeds, corner hard, or have to swerve to avoid something. Personally, I prefer the stiffer suspension because it better suits my driving style (aggressive).

[Reg Hinnant]

Denee,
My post, where I was answering skunkworks, should have been worded different.
Some have slit the 1st bumper to lessen the impact on the rear of the vehicle, since there is only a small amount of clearance between the axle & bumper. I have not done this but know a few owners who have and they feel it helps ease the rear stiffness feeling.

[Hotsauce]

I think most VX owners who feel their ride is too stiff will discover that their shocks are actually worn out.

Before you change out for soft shocks, see if its not just that yours are gone.

John C.

[Chopper]

Stiffen those sway bars at your own risk my friend. This is no lightweight ballerina we're talkin' about. Your *** will quickly be introduced to your nose.

[transio]

Update: I've been riding on these Bilsteins for almost a month now, and the ride is just fabulous. My VX is really tight around corners and has little body roll. Of course, I have tried not to push it TOO much. I have been driving sports cars for 5 years, so I'm still a little wary about flipping this thing!

[VR4-Quest]

Transio, are they equivalent or softer/stiffer than stock? I think the question we all want to know (those looking for replacement shocks) is if they will performe just as well as stock (mainly the exceptional handling and stiffness the OE KYB's provide). I tried the Rancho 9000's on the 9 setting and they are still softer than stock and too soft for my tastes.

I have had yet another front shock go bad, this time, one that was replace just 12,000 miles ago (covered by warranty at the time, but not anymore), so I need a good stiff aftermarket shock!

Thanks!

[Reg Hinnant]

Mike,
Hotsauce told me that the Bilsteins were almost as stiff as the original shocks but not as responsive. He had the H2's on front. He was also concerned about the life span of the Bilsteins.
He had Ranchos before and had the same problem as you.

I'm afraid that its just not possible to find a $60.00 shock that is as good as the $350.00 originals. Nor designed to match this vehicles unusual characteristics.
:confused:

[transio]

I can't compare the Bilstein H1's with stock, because my stocks were shot in the back when I got the VX, and I swapped out all 4 at once.

I can, however, say that the VX is EXTREMELY responsive, and EXTREMELY stiff. with these shocks on. I'm 100% satisfied with them.

I keep taking corners a little harder to see if they'll give a little, but they don't. My feet stay planted firmly. I feel like I'm driving a big, heav sports car.

EDIT: Reg, I think you should try these babies on for size. They may shock you! (pun intended) ;)

[Reg Hinnant]

Steve, Sorry if I sounded a bit negative!

Believe me, I would love to be shocked close to the originals, at 1/4 the price! heh heh :D

Maybe the H1's in front are a good answer; I would like to know Hotsauces thoughts on them.

It’s hard to keep putting money down and being disappointed. :mad:

[transio]

Reg, all I can say is if you're ever in FL, stop by and I'll let you try her out and decide for yourself how the ride is! :p

[VR4-Quest]

I'm so tempted to try these, maybe I'll order one like I did with the Ranchos and see how they stack up to stock, I want something as stiff or stiffer.

[VR4-Quest]

Transio,
were did you get your Bilsteins, especially the H1 fronts, seems all the online places only have the less stiff H2 listed for the front Tropper application?

Hotsauce, have you evaluated the stiffer H1 fronts (your comments where that the Bilstein set up is almost as stiff as stock, maybe the H1 fronts will make it as stiff?

Thanks guys!

[transio]

Originally posted by VR4-Quest
Transio, were did you get your Bilsteins I got them from DeNunzio Racing:

http://www.denunzioracing.com/bilstein/suv_isuzu.htm

[SlowPro48]

Originally posted by transio


<<<snip>>> #1
That means that whatever happens inside doesn't matter.

<<<snip>>> #2
The shocks are in compression, with a pin joint at either end. The vertical force gets translated along the axis of the shock absorber, which then pushes back with a vertical AND horizontal load. The horizontal load gets absorbed by the wheel's mounting bracket (and whatever assembly that is attached to). Because the shock absorber is at an angle, it has to handle not only the vertical load applied by the road, but the horizontal loads created by the fact that it's angled. Essentially, it makes the shock work harder than it would in a vertical mounting position.

<<<snip>>> #3
Additionally, it's not making the shock travel less. That's a misconception. The shock actually has to travel MORE for the same amount of wheel travel.

<<<snip>>> #4
I don't see one benefit to having the shocks mounted this way.


Well I just logged on here to ask a stupid engine question but now I've seen this so it looks like I'll have to run my mouth some more. Please forgive me - I'm not trying to start an argument - but it seems to me that some of your logic is 100% backwards from the way I see things! What up with that???

Here are my responses to your points as quoted above:

1. Actually, whatever happens inside is the ONLY thing that matters as far as force transmitted by the shock. The force vector diagrams you provided apply to solid rods, etc. But our shocks are not solid.

Just forget all that vector stuff and do this little gedanken experiment. Envision a shock in which there is no oil - say it's brand new and comes with a couple different weights of oil and you just haven't decided which viscosity to use therefore you haven't filled it yet - so there is NO damping. And the pistons, rod, seals, etc are all made of Unobtanium, a new alloy that is completely frictionless. You're holding this trick $5000 shock in your hot little hands - just marvelling at how easily it slides in and out. How much force does this take? Practically none! There's no damping and no friction so all your hands feel is a wee bit of inertia as you accelerate the mass of the shock body.

If you mount the shocks on the VX like this how much force will they transmit from the axle to the frame when you whack that big speedbump at the mall? NONE!!! There's nothing going on in that shock. It's all spring and no shock, baby! The VX soaks that bump right up - but then it proceeds to pogo your ***** into the next lane and you almost sideswipe a bluehair in a Fleetwood Brougham. You decide you better put some oil in those babies. You take them off and fill them to the proper level with the lightest oil. You're compressing and expanding the shock - working the bubbles out - you feel the damping now and you notice when you push as hard as you can it takes about 4 seconds to completely collapse the shock. This pectoral workout reminds you of when you were a kid and got hold of your sister's Mark Eden Bust Developer. Then you discovered the instruction booklet with those pictures of June Wilkinson......

Whoa! Major derailment there! Get that thought train back on the tracks. On with the gedanken! So - you slap the shocks back on, hit the same speedbump and notice it still soaks the bump up pretty good but there's also still a lot of bouncing afterwards. Rides kind of like that Fleetwood you almost hit. So you decide to use the thicker oil to slow down the rebound. It'll stiffen up the compression damping too. This time when you're working the bubbles out it kind of reminds you of your dad's Bullworker. You're pushing as hard as you can and it takes a good 10 seconds to collapse the shock. You're thinking man this is going to be a stiff ride. When I hit the bump this time the shock is going to put up a fight. There's going to be some major damping going on. It's not going to collapse easily. It's going to transmit a lot of force from the axle to the frame.

Do you get where I'm going with this? What goes on inside the shock DOES matter. If you don't get it then take the gedanken one step further. Say you're still thinking about June Wilkinson when it comes time to change the shock oil. You're distracted and you fill them with 90W gear oil so they hardly move - no better yet - you're so distracted you fill them with some epoxy resin you had mixed up and set aside for another project. It sets up and by the time you get the shocks installed on the VX they are basically solid rods. ***In other words, they are what you depict in your vector diagram!***

NOW what happens when you hit that speed bump? No spring action at all! The shocks transmit ALL the force. Depending on how fast you hit and the slope of the speedbump, that force approaches infinity and either the axle, the frame or the shocks will yield as they try to accelerate the 4000lb VX against gravity at an impossible rate. Get it? As far as force transmitted by the shock, what happens inside is the ONLY thing that matters.

2. The shock is compressed in one plane and, as you noted, is mounted on pins at both ends. The pins are perpendicular to the plane of motion - like a bicycle wheel and axle. The shock body halves are therefore free to rotate as the shock is compressed and so the shock doesn't see a vertical or horizontal component per se. The shock just feels squished along its axis and that's all it knows.

3. Nope. Shock at an angle will travel less. Do another thought experiment. Think of a dirt bike swingarm with shock straight up and down, mounted at the axle. One inch of wheel travel compresses the shock 1 inch. Now lay it over as far as it will go - that's right - parallel with the swingarm! Hey! The wheel's moving up and down but the shock's not being compressed at all!!!

4. Uh, let's see.... I've got it! A real world demonstration! Show up at the Swamp Fox enduro (1/16/05, Charleston, SC) and I will locate a vintage bike like maybe a 1966 Maico with straight up and down shocks for you to ride. After 70 miles of sand whoops with 4" of suspension travel I bet you will see the benefit to lay-down shocks....

[SkidPlate]

I had the H1's installed this weekend and I have to say I am impressed. They are VERY close to stock performance.

My stock shocks were starting to go after three years of owning the VX, the front left was actually blown, and these Bilsteins brought it back to the handling I remember. First thing I said when I left the garage "now this is the truck I bought"!

I would highly recommend these to anyone looking for a reasonably priced shock replacement with damn near stock performance. Once again, the model numbers are:
Bilstein
F: B46-1738-H1
R: B46-1739-H1

[transio]

SkidPlate, glad to hear it!!! I love the H1's too!

[transio]

SlowPro,

Don't think of it as "argumentative". If we learn something from this conversation, it has value.


Originally posted by SlowPro48
1. Actually, whatever happens inside is the ONLY thing that matters as far as force transmitted by the shock. The force vector diagrams you provided apply to solid rods, etc. But our shocks are not solid. I was under the impression that a dynamic system acts like a static system at any given instant in time. In that case, wouldn't the force diagram apply at that instant? Also, wouldn't what happens inside be dependant on the force applied?


2. The shock is compressed in one plane and, as you noted, is mounted on pins at both ends... The shock just feels squished along its axis and that's all it knows. That's my point. The shock is taking the force of the vertical load and transferring a diagonal force, which contains vertical AND horizontal loads. Then, the horizontal member applies a back-load to balance it out. Overall, you're being less efficient because you're adding horizontal loads. At 45 degrees, those loads equal the verticals.


3. Nope. Shock at an angle will travel less. This is a matter of geometry. Assuming that the shocks are mounted at the same relative point on the axle, the shock at an angle will always have less vertical travel. This is because for every inch of UP travel, the same shock also has to travel SIDEWAYS. Think of a 45 degree triangle. the hypotenuse (angled member) is always longer. A straight line is always most efficient.


4. A real world demonstration! Show up at the Swamp Fox enduro (1/16/05, Charleston, SC) and... you will see the benefit to lay-down shocks.... This is highly possible. Ideal math doesn't always work best in the real world. If you tell me that lay-down shocks out-perform vertical mounts hands-down, I'll believe you, but I'm just trying to figure out why! :D

[SlowPro48]

Alright I give. When you start talking about hippopotomuses I get all confused. I was thinking regardless of all that geometry stuff, the shock can only transmit as much force as the damper assembly will allow. Seems like even if you apply a million pounds to the axle at the rate of 1 inch per second for 3 seconds - if the shim stack and oil in the shock only resists with a force of 25 pounds at that rate then that's all that will be transmitted to the frame - 25lbs - no matter what the angle of the shock. But maybe I'm wrong. It sure has happened before!!!

Actually I think this started as a discussion about what was causing premature failure of the shocks so who cares about force transmitted, right? The horizontal and vertical loads you mention - no matter what they are - apply only to the pins attaching the shock to the frame and axle housing. The shock rotates around a pin at either end and thus will only be subject to axial loads. This is a good thing because the shock isn't designed to be subject to side loads. If the bushings are seizing on the pins for some reason then that would subject the shock to side loads and may cause premature wear of the rod/seal. While unlikely, I guess it could happen. Might be something to check out though!

Are the shocks all leaking or are they just going soft on you without losing fluid? Are the rods being scored?

Oddly enough, just yesterday I saw a shock that had been subjected to a side load. My suspension guy invited me over to his place at the lake to do some jet-skiing and he showed me a shock off a KTM. It was a White Power PDS shock - a linkless type - so it has to be laid way over to get the needed 12 inches of travel. The rod was snapped clean in two. It didn't have anything to do with the angle of the shock though. The bike had been crashed at the last hare scramble and it went down on a pointy rock, with the shock taking the brunt of the hit. It was working fine right up to that time. All laid over... Just like on millions of other motorcycles... and ATVs.... and off-road racing trucks, buggies and rails... Formula 1 cars... IMSA GT cars... and even on my trusty old 1982 GMC 3/4 ton truck with over 300,000 miles on it. Hmm... Must be SOME advantage to angled shocks...

Calculate on THAT a while!

[SlowPro48]

Originally posted by SkidPlate
I had the H1's installed this weekend and I have to say I am impressed. They are VERY close to stock performance.

My stock shocks were starting to go after three years of owning the VX, the front left was actually blown, and these Bilsteins brought it back to the handling I remember. First thing I said when I left the garage "now this is the truck I bought"!

I would highly recommend these to anyone looking for a reasonably priced shock replacement with damn near stock performance. Once again, the model numbers are:
Bilstein
F: B46-1738-H1
R: B46-1739-H1

What are you going to do with your old shocks?

[SkidPlate]

Originally posted by SlowPro48
What are you going to do with your old shocks?

Actually, I left the old shocks at the garage for them to dispose of. I really don't think they were worth much, if anything, especially now that I see how the Bilstiens perform. Like I said, one of the fronts were blown and I'm sure the others were not too far behind.

If I had thought someone would be interested in them, I would have kept them. :eek:

I can understand why you may want to stick with the old shocks. I was aprehensive of getting rid of them myself. I thought, how could some monotube shock perform as well as these? Well, I was wrong. I think you would be surprised with how well the Bilsteins work. Do yourself a favor and give them a try, you won't regret it.

-Rob

[transio]

I have a good set of stock fronts with 25k miles on them if anyone wants to make me an offer! :)

[transio]

Originally posted by SlowPro48
Seems like even if you apply a million pounds to the axle at the rate of 1 inch per second for 3 seconds - if the shim stack and oil in the shock only resists with a force of 25 pounds at that rate then that's all that will be transmitted to the frame - 25lbs - no matter what the angle of the shock. Good point. I hadn't really thought of it that way. But what if your force is less than maximum resistance? What if it's 15 pounds? if lay-down shock takes 15 pound vertical loads as 25 pound axial loads, then it's doing more work. Also, if it travels 18" versus 12", it's doing more work. It may perform better, but I'm pretty convinced that performance increase is at the expense of shock life. That's something that's common in all aspects of racing.

[SlowPro48]

Originally posted by SkidPlate
Actually, I left the old shocks at the garage for them to dispose of. I really don't think they were worth much, if anything, ...


Wonder if they've still got them...


They might not be worth anything but I'd like to get my hands on some that have failed and show them to my suspension guy. Guess I'll just have to wait until I've got my own trashed set!!!

[SlowPro48]

Originally posted by transio
Good point. I hadn't really thought of it that way. But what if your force is less than maximum resistance? What if it's 15 pounds? if lay-down shock takes 15 pound vertical loads as 25 pound axial loads, then it's doing more work. Also, if it travels 18" versus 12", it's doing more work. It may perform better, but I'm pretty convinced that performance increase is at the expense of shock life. That's something that's common in all aspects of racing.


Dude -

1. There is no "vertical load" on the shock.

2. The shock doesn't care if there's 15, 25, or 25,000 pounds pushing on it. It only cares how quickly it's being compressed and extended. It's just two pieces of metal held together by some oil. When moved, it squishes the oil through one set of orifices or another (compression or rebound damping circuits) and the force transmitted depends on the specifics of the damping and the speed with which the two shock halves are being pushed together or pulled apart.

The shock also doesn't care if it's straight up or at a 45 degree angle. It's still got the same oil and same holes to squish it through in order to resist movement. BUT - fortunately smart engineers DO care about shock angle because by tilting the shock they can get more suspension travel without raising the ride height/center of gravity of the vehicle.

Can you imagine a dirt bike with 12" of suspension travel and vertical shocks? The shocks would have to be over 24" long. When you consider the reservoir, mounting eyes, etc. the shock would actually end up being nearly three feet long. Add half a wheel diameter to that and we've got a seat height of at least 4 feet....

It's the same with 4 wheeled stuff. In most cases, low c.g. is the way to go.

I guess theoretically it could reduce the life of the oil in the shock slightly. Since canted shocks travel less, the shaft velocities will be a little higher than if the shock were mounted vertically. The oil might thin a little sooner. If that's the case, I'd say the trade-off is worth it. Not just for high performance applications either. I wouldn't want the bed of my GMC any higher than it is. So I'm glad the shocks are tilted. And they seem to last just fine that way. 300,000 miles and only had to replace the shocks once.

If VX shocks are going bad at 30,000 then there's something else going on besides the fact that they're tilted - especially if they're leaking. Sure would like to get my hands on some and see what the problem is...

OK, Mr. Transio - I've flogged this horse enough. How about you?

[transio]

Originally posted by SlowPro48
OK, Mr. Transio - I've flogged this horse enough. How about you? Not at all! :) I'm actually learning something!

Re: "more travel", you're right. After looking at my diagrams a bit, I realized that I put the rotation point of the axle directly beneath the frame mounting point of the shock absorber. By putting it at an infinity, it changed a lot. My bad! :)

Re: fluid dynamics, you say that all that matters is the speed with which the shock is compressed. What you're missing, though, is that the axial load placed on the shock is specifically what determines the compression rate. Bigger load = faster compression. Internally, the bigger load translates to higher pressure placed on the fluid, which simultaneously increases flow and outward pressure, tending (I guess?) to make the container of the fluid want to burst. If the container is of inferior manufacture, it will rupture?

[SkidPlate]

Originally posted by SlowPro48
Wonder if they've still got them...



Actually, they do have them, it seems that trash doesn't go till Friday. So let me know before then if you still want them, also which ones you want.

One of the fronts is blown and leaking fluid, the other is dry but will not recover from compression by itself. The rears looked ok, the one I compressed by hand was leaking air(?), I could hear it rushing as I worked the shock, could be normal, not sure. I didn't even look at the other rear, but it was dry. One thing for sure, these were all on their way out, large dips on the highway sent me for a little boat ride on the waves, if you get my meaning.

Let me know ASAP, they said they'll save these for me, if you really want them.

-Rob

[transio]

I've got 2 bad rears. They're yours if you want to pay shipping.

[SlowPro48]

Originally posted by transio
..... Re: fluid dynamics, you say that all that matters is the speed with which the shock is compressed. What you're missing, though, is that the axial load placed on the shock is specifically what determines the compression rate....

Haha! Man you're not going to let me slide on outta this discussion are you? Here's the deal - I'm missing a lot of things in life but that little tidbit of info is not one of 'em! I was just using the million pounds to illustrate the point that it doesn't matter how much "force" you apply to one end of the shock body, the other end of the shock will only transmit as much force as the internals will allow (i.e., as much as the damper is resisting the movement of the rod). What YOU'RE missing ;> is that in that example I specified a rate of 1 inch per second - as if the shockwere being compressed by a huge ram or something. It was just for demonstation purposes if you will - another gedanken experiment.

I can see why you might think I was missing something though because I used "pounds" to describe the force - which assumes acceleration due to gravity. I'm not an engineer or physics guy so I talk of force in pounds instead of proper terms like "Pound Force" or "Newton". Sorry. We both know if you put a million pounds on top of an extended VX shock here on earth and let it drop it would (for all practical purposes) fall at 32 ft/sec squared since the resistance generated by the damper would be nil compared to the force of 1 million pounds. But of course while it was falling through the travel of the shock, the bottom of the shock would only be pressing down on the earth the amount the compression damper could resist the shock rod's movement. If you had on steel-toed shoes you could - for an instant - be a hot dog and balance a million ponds on the end of your foot! And about a 30th of a second later - when it reached the end of the travel and the shock bottomed out - well then you'd have a crushed shock and a million pounds on your foot. Ouch!

But the heck with all that outrageous stuff. In the real world our VX shocks only have a thousand pounds or so above them. And practically speaking, that weight doesn't vary much during the typical drive. What determines the shock rod speed is simply the speed of the vehicle and the slope of the obstacle it's rolling over. If you hit a six inch high, four foot wide speed bump and you're doing 30 mph the shock will compress at a speed of about 11 feet/sec (just ignore tire sidewall flex, the car pitching up, etc .) I have no idea how a VX shock plots out on the shock dyno but let me tell you from personal experience - a speed bump like that will give the ol' shims a workout but the VX copes just fine. Haha - I hit that exact speed bump at 30 mph today - was tooling around Duke Univ. Med Center - late for an appt - never been there before - looking for the parking garage - not paying a bit of attention to the road - WHAM I nailed that hump. Fluid dynamics in action...

And to answer the other part of your question - yes, if you have a cheap shock with welded body and the rate of compression is extremely high you can end up in a "hydraulic lock" scenario and the shock body can rupture. This is much more likely with old style damper rod type shocks since they use a fixed orifice. There is a velocity squared relationship between flow and resistance - that is - if rod velocity is doubled you get four times the amount of resistance - quadruple the rod speed and you get 16 times the resistance. It adds up in a hurry and pretty soon you end up in a situation where the fluid won't pass through the damper quickly enough and internal pressure builds and if you've got a weak weld the shock could split. That hardly ever happens though. Most of the time the seal will blow or the shaft will bend before the body will split. With cartridge style dampers like what we've apparently got (don't know for sure since I've never taken one apart but I think someone on this board reported shim stacks) the shims flex away from the piston in response to increased speed thus increasing orifice size and preventing hydraulic lock. Heck they could probably even handle a million pounds without blowing up!!! ;>

[SlowPro48]

Originally posted by SkidPlate
Actually, they do have them, it seems that trash doesn't go till Friday. So let me know before then if you still want them, also which ones you want.

One of the fronts is blown and leaking fluid, the other is dry but will not recover from compression by itself. The rears looked ok, the one I compressed by hand was leaking air(?), I could hear it rushing as I worked the shock, could be normal, not sure. I didn't even look at the other rear, but it was dry. One thing for sure, these were all on their way out, large dips on the highway sent me for a little boat ride on the waves, if you get my meaning.

Let me know ASAP, they said they'll save these for me, if you really want them.

-Rob


Great googly moogly man those things sound completely trashed!!! They're dry? What in the world is going on here?! How many miles on them?

I'll gladly pay shipping if you're sure you don't want them. It sounds like you're pretty sure if you left them at the shop but if you ship them down here just know it's going to be like the French Revolution and my suspension guy's Port-a-Band is the guillotine!!!

[transio]

Originally posted by SlowPro48
Haha! Man you're not going to let me slide on outta this discussion are you? Just trying to learn, man :D


With cartridge style dampers like what we've apparently got (don't know for sure since I've never taken one apart but I think someone on this board reported shim stacks) the shims flex away from the piston in response to increased speed thus increasing orifice size and preventing hydraulic lock. Heck they could probably even handle a million pounds without blowing up!!! ;> Gotcha. That kind of blows my theory.

PS - iirc, even engineers and physicists use pounds as a measure of force. A pound of force can exist independant of gravity. It's when pounds are used as an identifier of mass that they become gravity-dependant.

PPS - thx for taking the time to explain everything :)

[t2p]

Can you imagine a dirt bike with 12" of suspension travel and vertical shocks? The shocks would have to be over 24" long. When you consider the reservoir, mounting eyes, etc. the shock would actually end up being nearly three feet long. Add half a wheel diameter to that and we've got a seat height of at least 4 feet....
.
I basically stated this (in this thread or another similar thread) a month or two ago. Oh well.
.
For the historians ....... Suzuki put a spotlight on this around 30 years ago when they introduced the 1975 RM125 with the long travel rear with canted shock absorbers.

[SkidPlate]

Originally posted by SlowPro48
Great googly moogly man those things sound completely trashed!!! They're dry? What in the world is going on here?! How many miles on them?

I'll gladly pay shipping if you're sure you don't want them. It sounds like you're pretty sure if you left them at the shop but if you ship them down here just know it's going to be like the French Revolution and my suspension guy's Port-a-Band is the guillotine!!!

Hehe, yeah, they are in rough shape, which is probably why I like the Bilsteins so much. There is only about 50k miles on them, but the freakin potholes around here just tore them all to h3ll. Im actually glad to hear that your tearing them apart, I wouldn't want to see anyone try and put them back on. I do expect a full report of what you find once the guillotine hits them.

I'll call the shop today and tell them to hold these shocks for me. I probably won't make it over there to get them till the weekend, hopefully your not in a hurry. I'll send you an email to work out the shipping details.

Actually, I see your from Winston-Salem... I'm going to be on Cape Hatteras for a week starting 8/28, want to stop and pick them up?

-Rob

[VR4-Quest]

OK, stupid question....so the H1's are stiffer, so why do they list them for the Rodeo and Amigo, and the H2's for the heavier Trooper?

[transio]

VR4, I was wondering the same thing. I got the info from the people at Bilstein, though.

[transio]

Just to get this thread back on topic:

Originally posted by SkidPlate
I had the H1's installed this weekend and I have to say I am impressed. They are VERY close to stock performance... I would highly recommend these to anyone looking for a reasonably priced shock replacement with damn near stock performance. Once again, the model numbers are:
Bilstein
F: B46-1738-H1
R: B46-1739-H1
That's two of us who concur! Who's next? :D

[SlowPro48]

Originally posted by SkidPlate
Actually, I see your from Winston-Salem... I'm going to be on Cape Hatteras for a week starting 8/28, want to stop and pick them up?
-Rob

Hatteras is about 8 hours away so shipping would be preferable. But now that I think about it, the female unit IS starting to make those 'summer's almost over when are we going to the beach' noises. And she likes the Emerald Isle/Beaufort area. Hmmm...

[SlowPro48]

Originally posted by transio
Just to get this thread back on topic:


whooops! sorry for the hijack!

[transio]

No need to be sorry! I learned a lot from your posts!

[SlowPro48]

OK Mr. Skidplate - she's not going for the Outer Banks trip because of a tennis tournament. Dang it. I wanted to try the hang gliding thing up at Jockey's Ridge. ( http://www.kittyhawk.com if you're interested and have time for a little side trip while you're at Hatteras)

Anyway, looks like shipping is the easiest way. Just email me whenever you get a chance so I can give you my address. I'll send money order or paypal you or something for the shipping and whatever you need for your time to pack/ship. Thanks.

[SkidPlate]

No problem Mr. SlowPro. I'll pack these up and get them out to you this week, once I have your address. I did send an email to your yahoo.com account, did you get that? If not just contact me on my ptd.net address. You can cover shipping via PayPal once I know what it is.

Oh, and thanks for the tip on Jockey's Ridge. I will check that out if I find time between fishing, drinking, and laying around in the sun. :snooz:

I'll wait to hear from you.

[Maugan_VX]

Skidplate: Drive up Rt. 12 until you run out of pavement. Then you'll still have miles of open beach and dunes to drive all over.

[SlowPro48]

Originally posted by SkidPlate
I did send an email to your yahoo.com account, did you get that?

Ha! I had forgotten I used the rarely checked yahoo account to set up vehicross.info. Sorry about that! Just sent you the info.

[VR4-Quest]

OK, so I order an H1 and actual got the trooper H2, just a single front shock to try. I tried the H2 and it felt great, almost like stock. SO I returned it to try and H1 which is supposedly stiffer, however, it actually feels softer. And that lines up with the fact its for a rodeo (lighter) and the H2 for a trooper (heavier). Other than Bilsteind saying the H1 is stiffer, has anyone compared the side by side? I order a H2 again and will compare to my H1 to put this question to bead!

[VR4-Quest]

OK, did the old hand calibration with a H1 and H2 front against a good OE front shock. H1 is stiffer than H2, and the OE is stiffer than H1. So the H1 is close, but noticably less stiff than stock. But for the money, its the closest thing to stock I have tried to date. Maybe the VX would behave better with a full set of the H1's on it, but I can tell a slight difference in stiffness while driving (a little more bounce out of the H1 side), plus the simple jounce test shows a difference, the stock shock settles after one bounce, the H1 maybe 1.5.
Not sure what I'm gonna do now, I just might shell out the $$$ for a OE front and hope all the others last for some time.