Coil Spring Buffers/Spacers (aka Spring Rubbers)

[K_Clack]

On my last trip from SoCal to Tucson for the 2024 24 Hours in the Old Pueblo mountain bike race, I loaded my '90 2WD Westy, "Maria," (with GoWesty lift springs and 225/70R16 tires) with 4 of my buddies, our bikes, gear, and all of our food, water, and beer.

We were quite loaded down. A few pics below for fun:

It was a fantastic trip and Maria handled great across the desert. However, my front springs were almost fully compressed and left me with little remaining upward articulation. I took it easy and avoided any large bumps I could. The trip left me wanting the ability to adjust the spring force proportionally to my anticipated gross weight.

My understanding is that spring buffers/spacers are sometimes used in racing applications to give incremental boosts in the overall available spring force with each buffer/spacer applied (10-15% per buffer for a standard vehicle).

Here are a few examples:
https://www.rubbershox.com/collections/universal-coil-spring-buffer-block
https://www.summitracing.com/parts/lng-61015?seid=...UrEALw_wcB
https://www.etrailer.com/Vehicle-Suspension/SuperS...JGEALw_wcB

I searched the forums and couldn't find any mention of "spring buffers, "spring blocks," or "spring spacers" that were related to the items discussed here. Does anybody here have experience using these on Vanagons or any other vehicle? Is there a reason they have not been discussed in past forums (Barring my oversight)? Is there any reason not to spec them out properly and install them in between the coils as needed?

Cheers 🍻
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'90 Vanagon GL Westfalia, "Maria" / Manual / GW 2.5
IG: @clackanis_kevinus

[MarkWard]

I would reach out to Christopher at T3 Technique. I’ve seen pictures of the GW progressive front springs installed and I don’t know how they even work. If you have coils binding the spring rate is too soft and honestly ride height is a by product of spring rate. Buffers will just make the ride harsher than it is. Best to have proper rated springs for you installed.
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[4Gears4Tires]

You want air springs, just like on a mtb, so you can adjust the sag fully loaded and get the right amount of travel without blowing through suspension.

The rear is really easy, there are bags that go inside the springs that are easy enough to install. Something like this https://airbagman.com.au/collections/999800312-air...dnr=106711 This is the easiest part and maybe transferring more load to rear is going to be the easiest solution.

The front is going to take some creativity. I don't think anyone makes any off the shelf parts to fit. You're going to need something like this part. https://www.ebay.com.au/itm/382942986928 and you'll need to measure the outer diameter of the strut, the inner diameter of the spring, and find something that can fit between the two. There has to be a lot of info on air bag suspension mods for Vanagons, but I don't know it.

Another option is going with GoWesty's Fox Suspension kit. It's the same IFP tech they use in all their shocks, including mtb. I don't need to tell you the difference better suspension makes. https://gowesty.com/products/fox-shock-absorber-set?_pos=1&_sid=2a5a50aec&_ss=r
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'87 Syncro
Ferric Oxyhydroxide Superleggera Edition

[Sodo]

Your trip looks like loads of fun.
Do it while you can. We used to drive from Seattle to Moab like that.
Great friends, 1000 miles, 15 hours, one shot - pedal to the metal.
Some of the funnest times of our lives.
Moab was a sleepy little town back then.

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A coil spring accommodates a specific weight.
There is a 'tolerance' around that specific weight.

A progressive spring tolerates a specific weight, and the "tolerance band" is narrower.
But while the gross weight is within that narrow tolerance band the performance is "higher" (smooth ride).
Compressed beyond that narrow 'tolerance brand' ....
a progressive spring gets much stiffer. This feature can prevent bottoming but the ride is real stiff.

Again.... coil springs are tuned to a "known weight".
Progressive springs are "more tuned", but if the weight goes outside that (tighter) band, the ride gets real harsh, but has better resistance to bottoming.
Got that?
Red it as: "no free lunch".

The only way you can get your van to perform in the conditions you described is to find air shocks.
4G4T mentioned an air shock for the rear.
I don't recall any air shock available for the front of a Vanagon.

Fox Shocks have an adjustable spring perch for the front.
For this case you would load the van with all your favorite 180lb meat-bombs and their gear & food then "adjust ride height"
with screw-collars
....to that meatbomb count.

I predict that you will LOVE your Fox Shocks..... but....
You will only do this 'ride-height adjustoment once.
It's difficult. Never again.
You have to use spring-compressors and you have to fabricate special tools etc.

Anyway the short answer is, you can't spring a Vanagon to (variably) accommodate such a wide range of gross weight.
"Avoiding large bumps" is basically all you can ever do.
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[Christopher Schimke]

The front springs in question are not progressive, they are dual-rate. What this means is that as they compress from zero load, they have one rate (which in this case is fairly low) until the closely wound coils bind, then the rate jumps way up (in this case).

This is an extremely hard condition for shocks to handle since the shocks need to be soft enough for the first part of the travel to offer a decent ride quality, but they need to be stiff enough to be able to control the higher spring rate at the same time. The wider the discrepancy between the softer rate and the stiffer rate, the harder it is to tune a shock to handle both scenarios effectively.

Adding spring rubbers will increase the spring rate which will most likely make this condition worse.
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"Sometimes you have to build a box to think outside of." - Bruce (not Springsteen)

*Custom wheel hardware for Audi/VW, Porsche and Mercedes wheels - Urethane Suspension Bushings*
T3Technique.com or contact me at [email protected]

[K_Clack]

Thanks for the responses. I like there term "Spring Rubbers" rather than "Spring Buffers/Spacers." Sounds like if you are to add spring rubbers (especially to a dual-rate spring), it should be done so methodically to try to achieve a stiffer more linear spring curve when under load.


Link



Link


Shorter rubbers should first be added to the more tightly wound (softer spring rate) portion of the spring to increase the spring rate of this section (and avoid harsh transitions).
-Perhaps something like this: https://www.rubbershox.com/products/universal-modular-coil-spring-buffer

Next, if the ride height and overall spring rate is still too soft, thicker rubbers (of desired hardness) can be added to the sections of wider-wound (stiffer spring rate) portion of the spring as needed.
Thicker rubbers like these: https://www.rubbershox.com/collections/universal-coil-spring-buffer-block

I really like the idea of air bag-over-strut suspension for the front, but as mentioned, I haven't seen anything available and/or rigorously vetted. I hope not to provide too much dilutive discussion.

This discussion goes back pretty far, but has most recently been discussed in the threads below. MarkWard and Sodo both contributed to these topics. Looks like the second thread from 2020 includes the bags mentioned by 4Gears on a syncro strut modified to a 2wd Vanagon.
https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0
https://www.thesamba.com/vw/forum/viewtopic.php?p=9458022&highlight=front#9458022

I do see that X2 Industries claims to offer a "complete bolt-on kit" used to lower the vehicle. The website mentions to contact them for applications designed to lift the vehicle above stock ride height. But again, I've never seen them mentioned anywhere else.
https://www.x2industries.com/product/1980-1992-vol...10567206-2

This thread also mentioned a kit that used to be provided by MyHotVW, but I don't think they exist anymore.
https://www.thesamba.com/vw/forum/viewtopic.php?t=455089

I also like the idea adjustable spring perches, but I dont't think these exist for 2WD front suspension. @Sodo, I believe only the Syncro front suspension has the adjustable spring perch, correct? Are there any 2WD front shocks that offer an adjustable spring perch?

[Addition]: Sounds like you can install the syncro struts on a 2WD Vanagon. Seems like an excellent option.
https://www.thesamba.com/vw/forum/viewtopic.php?p=5631163
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'90 Vanagon GL Westfalia, "Maria" / Manual / GW 2.5
IG: @clackanis_kevinus

[Mateo83]

[Christopher Schimke]

[MarkWard]

Once the coils are binding either metal on metal or with inserted solid buffers, in my opinion that section is no longer a “spring”.
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[E1]

^^^ Interesting and true.

Does the rubber collapse enough to at least cushion harsh “bottom out” a little? That’s a condition begging for other major wear, in my book.

Great topic though and Thanks for starting it. I could see the value of rubbers if the spring isn’t prone to full compression to start with, i.e., more than enough spring length to fully accommodate the corner weight in worst-case demands.
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‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[Christopher Schimke]

[E1]

^^^ Awesome, Thanks.
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‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[ALIKA T3]

[Christopher Schimke]

[MarkWard]

Christopher is correct in my experience. I tend to interchange progressive and dual rate when talking about springs that aren’t linear. If we had the space we’d be running dual springs one on top of the other. Baja racers use this setup. For an example. You could run a 6 inch free height 250 pound spring and a 500 pound 6 inch free height spring. Here’s where I need to check my notes. You don’t end up with a 750 pound spring. I recall it’s actually the opposite direction. On the smooth you are riding on the 250 pound spring. As it compresses its rate goes up till the coils bind, now you are on the 500 pound spring. The transition is hardly noticeable. When the suspension unloads, The softer spring helps to absorb the tension of the 500 pound spring releasing,

This conversation comes up often. Tuning ride height is only one part of the equation and is the least informative way to discuss springs and rates. I’m still running our original springs on our 82. They work for us.

Dual rate or progressive. Once the coils bind, you remove the section from the rate. This is not good for consistent handling. As I stated originally, if you desire to go with a different spring, work with Christopher at T3. He has done the homework. One last point. The ideal ride height at rest would have the shock strut at mid point. This gives you the maximum range of compression and rebound. This is not Vanagon specific. This is true of all coil spring suspensions.
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[Sodo]

[Mateo83]

[Mateo83]

I've never had a good experience with dual-rate coils in any application. Single rate applied properly works great.
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83 Air-cooled 2.0 Tin Top

[E1]

We’re soon to buy from T3, and am not even interested in anyone else on suspension bits.

Don’t scare me like that!

https://t3technique.com/collections/springs-shocks/products/schwenk-2wd-and-syncro-spring-sets
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‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[Christopher Schimke]