rear shocks - monotube vs twin tube - Defender Source
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  #1  
Old June 26th, 2015, 12:27 PM
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rear shocks - monotube vs twin tube

Trying to select between monotube and twin tube shocks. Need them in 14 inch travel eye to eye for the rear on rockware mounts.

Twin Tube:
If I go twin tube, the current plan seems to be to go cheap. It doesn't seem to make much sense to me to go for an expensive adjustable twin tube (a la RS9000) when they cost as much as a rebuildable monotube (Doetsch Tech M2R, M2S, or Fox 2.0). There's a variety of cheap twin tubes with decent performance, including the Rancho 5012.

The general price seems to be around $100 +/- $10 for a pair.

Monotube:
I've seen the demonstrations of the advantages of monotubes vs twin-tubes.
The general price for entry-level rebuildable monotubes seems to be around $250 for a pair.

My Rear springs:

360 lb/inch

I already run OME Nitrochargers in front and they seem to be fine. Is the monotube vastly superior to the twin tube for someone who isn't a Baja racer and only drives off-road at speeds under 5mph? I'm not really a hardcore rock crawler, but I am usually tempted to buy expensive stuff because I am one of those losers who instinctively thinks expensive == better.

Any words of wisdom?
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  #2  
Old June 26th, 2015, 12:29 PM
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Are you referring to monotube vs twin tube being standard vs remote reservoir? Or twin tube as in 2 tubes with the nitrogen and oil?
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Old June 26th, 2015, 12:36 PM
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good question, Zack. Sorry I wasn't clear.

When I refer to "Twin Tube", I mean:

Shocks with an internal sleeve that the shaft piston rides in. A valve at the bottom of the internal sleeve separates the inner sleeve from an outer sleeve, which contains additional shock oil and pressure nitrogen or air, which are free to mix.

When I refer to "Monotube", I mean:

Shocks with one tube. No internal sleeve. A free-floating piston below the shaft piston totally isolates a volume of pressurized air or nitrogen from the shock oil. There is no mixing of the shock oil with the pressurized air or nitrogen.

AFAIK, both twin tube and monotube shocks can be converted to remote-reservoir operation. However, I am excluding remote reservoir shocks from my choices as I am totally convinced that I don't need them.
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Old June 26th, 2015, 12:41 PM
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Quote:
Originally Posted by sonoronos View Post
I'm not really a hardcore rock crawler, ...
No need to sell yourself short.
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Old June 26th, 2015, 12:48 PM
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Ranchos I had were junk; 3 of the 4 were blown when removed. Go with FOX!
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  #6  
Old June 26th, 2015, 12:57 PM
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I had Rancho 9000's, they blew. Now have Fox 2.0 Emulsions, much mo better.

14" travel? What are you doing with your rear trailing arms? You'll never utilize that 14" of travel on stock pin-style trailing arms. If you try you'll be eating bushings left and right.
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Old June 26th, 2015, 01:05 PM
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Quote:
Originally Posted by sonoronos View Post
good question, Zack. Sorry I wasn't clear.

When I refer to "Twin Tube", I mean:

Shocks with an internal sleeve that the shaft piston rides in. A valve at the bottom of the internal sleeve separates the inner sleeve from an outer sleeve, which contains additional shock oil and pressure nitrogen or air, which are free to mix.

When I refer to "Monotube", I mean:

Shocks with one tube. No internal sleeve. A free-floating piston below the shaft piston totally isolates a volume of pressurized air or nitrogen from the shock oil. There is no mixing of the shock oil with the pressurized air or nitrogen.

AFAIK, both twin tube and monotube shocks can be converted to remote-reservoir operation. However, I am excluding remote reservoir shocks from my choices as I am totally convinced that I don't need them.

That makes sense, it's just sort of rare to hear someone use it the correct way haha.

That being said, I am a huge fan of both sets of Fox shocks that I have. They're very well made and ride great.

I'm with Brett though, 14" is a ton!
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Old June 26th, 2015, 01:12 PM
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Unless you are building a completely different linkage and spring system, you will never use 14" of travel. Not that there is any use for it to begin with.

As to the shock question, you are not saying at all the intended use. Makes a big difference.
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Old June 26th, 2015, 01:22 PM
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Quote:
Originally Posted by fishEH View Post
14" travel? What are you doing with your rear trailing arms? You'll never utilize that 14" of travel on stock pin-style trailing arms. If you try you'll be eating bushings left and right.
My setup is rockware rear shock mounts, RTE trailing arms.

On stock shocks (8" travel, I believe), even with slight drop on the upper mount, I don't have enough shock travel to unseat the rear springs after my lift.

I remember talking to huff and he mentioned limit straps to prevent bushings from getting destroyed so your point is well taken.

------ Follow up post added June 26th, 2015 01:24 PM ------

Quote:
Originally Posted by Red90 View Post
Unless you are building a completely different linkage and spring system, you will never use 14" of travel. Not that there is any use for it to begin with.
Quote:
Originally Posted by Z.G.
I'm with Brett though, 14" is a ton!
points taken!

Quote:
Originally Posted by Red90 View Post
As to the shock question, you are not saying at all the intended use. Makes a big difference.
The intended use is slow speed off (sub 5mph) east coast rock crawling. Rausch Creek / Cove mostly.

ok...so I'm getting a lot of responses saying that Fox is better. But is it $150 better?

------ Follow up post added June 26th, 2015 01:31 PM ------

BTW I'm really confused about fox's 2.0 emulsion shocks. Why would Fox sell an emulsion shock, which is basically a twin-tube shock without the packaging efficiencies of an internal sleeve? What's the advantage of this design over Fox's own IFP monotubes which completely separate the oil from the gas? It just seems like a big step backwards and the cost is much higher than standard twin-tube shocks.
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Old June 26th, 2015, 01:36 PM
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It is a step backwards. You definitely want the oil and nitrogen separated, unless you're into that. I think the only benefit would be slightly better heat dissipation.

Edit- and yes it's $150 better
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Old June 26th, 2015, 01:43 PM
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It blows my mind. The Emulsions cost $40 more a corner than an IFP. There must be something I'm missing other than simply profit-mongering by the off-road industry.
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Old June 26th, 2015, 01:51 PM
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Quote:
Originally Posted by sonoronos View Post
My setup is rockware rear shock mounts, RTE trailing arms.

On stock shocks (8" travel, I believe), even with slight drop on the upper mount, I don't have enough shock travel to unseat the rear springs after my lift.

I remember talking to huff and he mentioned limit straps to prevent bushings from getting destroyed so your point is well taken.
Sure, but that does not take you from 8" to 14"..... the stock linkage geometry can't take that much movement. Going to 10" would be fine, giving two more inches of droop.

I thought really long travel died off ten years ago when people realised drooping wheels 2 feet did nothing other than look cool in pictures.
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Old June 26th, 2015, 01:56 PM
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Quote:
Originally Posted by sonoronos View Post
It blows my mind. The Emulsions cost $40 more a corner than an IFP. There must be something I'm missing other than simply profit-mongering by the off-road industry.
IFP's weren't a thing when I bought my Fox shocks. That said, I sprung for quality shocks because they are 100% rebuildable and can actually be resold for a decent amount of money.

The RTE arms will help a little with bushing bind, but nowhere near enough to use all the shock you have. I don't have your measurements to work from but I'm guessing that with a 14" shock you will have VERY little uptravel, even with Rockware mounts.

12" shocks, 3" RTE springs, Rover Tracks cranked arms, and 315/75/16 tires for reference.
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Old June 26th, 2015, 01:59 PM
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With 14" drop, you better have some good driveshafts, cause they gonna bind!!

And I switched to Fox a couple years ago, and yes- that much better IMHO. I even run them on my F-350 over Bilsteins and others....
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Old June 26th, 2015, 02:03 PM
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Quote:
Originally Posted by fishEH View Post
IFP's weren't a thing when I bought my Fox shocks. That said, I sprung for quality shocks because they are 100% rebuildable and can actually be resold for a decent amount of money.
Understood, Brett. This was not meant to be a criticism of your choices in equipment. Full confidence there. More of an abstract discussion of why such systems exist. The rebuildability and incremental improvements in construction make a case.
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Old June 26th, 2015, 02:04 PM
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Quote:
Originally Posted by Red90 View Post
Sure, but that does not take you from 8" to 14"..... the stock linkage geometry can't take that much movement. Going to 10" would be fine, giving two more inches of droop.

I thought really long travel died off ten years ago when people realised drooping wheels 2 feet did nothing other than look cool in pictures.
That's not exactly true. Having wheeled the same truck with open diffs on OME Nitrochargers and then long travel Rancho 9000's I can tell you keeping your tires in contact with the ground improved things a LOT. Adding lockers lessens the need for long travel suspension but not entirely. That said with a lot of travel in the rear and a stiff front(inherent to the design) you end up being sorta tippy in off camber situations. My current build will utilize jointed rear trailing arms and a rear sway bar for stability without affecting travel.

Quote:
Originally Posted by sonoronos View Post
Understood, Brett. This was not meant to be a criticism of your choices in equipment. Full confidence there. More of an abstract discussion of why such systems exist. The rebuildability and incremental improvements in construction make a case.
No sweat. I didn't take it as an insult.
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Old June 26th, 2015, 02:14 PM
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Originally Posted by down_shift View Post
No need to sell yourself short.
Hahah! That was a long time ago
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  #18  
Old June 26th, 2015, 02:20 PM
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Given the amount of binding going on when dropping over 10-12" and the spring preload is gone, just what is the benefit? Yea, the tire is on the ground, but with little beyond is own dead weight keeping it planted. But does it provide any traction when locked?
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Old June 26th, 2015, 02:46 PM
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It also allows the shock to do its job.

My understanding is that without droop, the shock no longer controls body roll, wheel hop, or suspension travel and the truck basically goes all over the place.
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Old June 26th, 2015, 04:06 PM
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What's Galpin running?
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