Jeep Tech: Monotube vs. Twin-Tube Shocks

By Christian Moe - July 2, 2015

It’s one of those random questions that every Jeep owner has pondered at least once: What’s the difference between monotube and twin-tube shocks? Sadly, its also one of those questions that lots of people seem slightly afraid to ask, as if we will shun them for their ignorance. Well, one of our fearless forum posters, RN M OVR, decided it was time to ask his fellow Jeep-lovers. He was given sound advice almost immediately.

Since I love to do my part to help out, I decided I would throw some of my knowledge in with what has already been posted and do what I can to make sure the next guy or gal has all the information they need to make an informed decision.

Let me start off by making a few things clear. Like all things relating to Jeeps and upgrades, think of this information as a simple base from which to build. Not everything here will apply directly to every application. These are just the generally accepted truths regarding two basic shock designs. I am also going to try to keep this as friendly as possible and skip as much of the really nerdy stuff as I can. Don’t worry if you don’t have an engineering degree. With that out of the way, let’s get into the good stuff.

Twin-Tube Shocks

These are what come on almost every single mass-produced car in the world. Twin-tube shocks are relatively affordable to make and they have a great balance of ride comfort and control. This design has some faults that are related to excessive/extreme use and cost savings. Twin-tube shocks feature a gas and a fluid combined in a single chamber; a valve controls most of the damping. There’s a secondary chamber in this shock that holds excess fluid to be added or removed as needed during usage. The gas in these shocks is usually standard air or nitrogen. Air shocks are cheaper, but are more prone to performance fade.

In the grand scheme of things, twin-tube shocks are more than most buyers will ever need and they offer a great combination of off-road ability, on-road comfort, and affordability when they need to be replaced.

Monotube Shocks

Monotube shocks are much nicer, much more expensive, and, depending on your usage, much better performers. One of the biggest changes here is that the fluid and gas are in separate chambers inside of the shock tube. This prevents aeration problems, helps to dissipate heat faster, and means that the shock is less prone to performance fade. The monotube design was created for racing applications and it’s used in all modern race cars, including those that compete in Formula One.

The big downsides to a monotube shock are its levels of comfort and cost. On average, a monotube shock will provide a much stiffer and less forgiving ride than a twin-tube shock. A monotube unit is also far more costly to produce and, therefore, much more expensive to buy. Such shocks do last longer on average, so they won’t need replacement as often as their less exotic cousins. If you’re in the business of fast off-road travel, though, they really can’t be beat. Thanks to their resistance to fade, these are the preferred shocks for anyone traveling at high speeds over rough terrain. If you’re building a trophy truck or a Baja racer, these are what you need.

Which is Better?

This is where things get weird. For a lot of weekend rock-crawlers, a set of monotube shocks would just be a waste. If you’re a semi-professional desert racer, you can blow a set of twin-tubes every race and that cost will outweigh the cost of a good set of monotubes which would work better for you. It all comes down to your needs and budget.

It’s also important to remember that not all monotubes are better than all twin-tubes. For the most part, just stick to the “paid what it’s worth” mantra. A really nice and pricey set of twin-tube shocks will most likely be much better than a cheapo set of monos. That said, a great set of monotubes will, on average, be much better than a similarly priced set of twins. You just need to lay out what you want to do, how much you want to spend, and then go from there. I hope this little bit of info can help you make the right decision.

A huge shout-out goes to RN M OVR for asking the question in the first place. Another big thanks to everyone who posted info in the main thread (below). If you have more questions about the topic or if you have more information to share, please head over to the thread and get to commenting. This is one of those times in which we can’t have too much information.