10/11th Gen Civic Sway Bar Info Guide

One of the first suspension modifications we usually recommend for Civics is a rear sway bar. The purpose of a sway bar is to reduce body roll when the car is turning. A larger diameter bar results in a stiffer spring rate which decreases roll more as diameter increases. One of the nice aspects about upgrading sway bars is they provide more capable handling without decreasing ride quality, because they are not very active when the vehicle goes over bumps. With these cars being FWD we always recommend to start with a rear sway bar upgrade to reduce some of the inherent understeering nature of the chassis. Front sway bars are a driver preference, some prefer a larger front bar, others prefer the factory front bar or even no front sway bar.

Before we dive into what options there are we're going to look at some aspects and adjunct parts that go along with sway bar upgrades.

Solid vs Tubular

Sway bars are either constructed from solid round bar, or from tubes that have a set wall thickness. Solid bars will have a higher spring rate, but also be heavier than a tubular bar of equal diameter. The relationship between wall thickness and spring rate is somewhat of an inverse of outside diameter's relationship with spring rate. As outside diameter increases the spring rate will increase by the difference in area (πr^2), so as wall thickness increases the spring rate will only go up by the difference in area as well, but since growing wall thickness means a shrinking inner diameter the gain in stiffness is not nearly as much as growing the outside diameter. In more simple terms, the spring rate goes up much more by increasing the outer diameter of the bar by 1mm versus increasing the wall thickness 1mm.

Adjustment Holes

The other large influence on sway bar spring rate is how long the arms of the bar are, basically the distance from the main straight section of the bar to where it meets the end link. The longer this arm is the softer the spring rate gets and the shorter it is the stiffer the spring rate gets. Having multiple holes at different distances allows for tuning of the sway bar because each hole changes the spring rate of the bar. This allows you to tailor the performance gain from a larger sway bar to better suit your desired handling characteristics of the car by making the bar softer or stiffer as desired.

Mounting Brackets

Sway bar mounting brackets are often an overlooked piece of the puzzle but important nonetheless. Factory sway bar brackets are made of relatively thin stamped steel, when a larger bar is put inside of them they are prone to twisting. When these brackets twist and deform the sway bar gains space to deflect, which reduces its ability to transfer load, essentially reducing the spring rate of the bar. So we always want to make sure that our sway bars are securely mounting for maximum efficiency when transferring load. Most of the larger rear bar options for the Civic come with billet or reinforced brackets for this reason. The front bar runs through the front subframe and is nestled inside of it so is no need for a stiffer bracket because it doesn't really use brackets.

A note on 11th gen rear mounting brackets, the rear brackets are integrated with the bar from the factory and are not serviceable so if you are installing a larger rear bar that doesn't come with new brackets you will need to buy brackets separately to install the bar on your car.

End Links

End links are another small but important part of the sway bar puzzle, they are responsible for transferring the cornering load from the control arm to the sway bar and vice versa, without them the swaybar is useless. With aftermarket sway bars that have multiple adjustment holes the factory end links are usually only able to utilize one of the mounting holes because they're a fixed length. This is where adjustable end links come into play, they are length adjustable so they can be used on multiple holes in the sway bar arms. It is important to set the end link length with the vehicle at ride height to ensure that the end links aren't too short or too long which would preload the sway bar (not desirable).

Both Eibach and Whiteline offer quality adjustable end links:

Eibach Rear | Eibach Front | Whiteline Rear | Whiteline Front

Sway Bar Options

The rear sway bar is interchangeable across all trim levels so any of these bars can be put on any 10/11th gen Civic. The stock rear bar size depends on the trim level of the car and is as follows:

• 16.5mm solid for EX, LX, Sport (2016-2021)
• 17mm solid for Touring (2016-2021), all trims except Touring, Si, Type R (2022+)
• 17.5mm solid Touring (2022+)
• 18mm solid for Si (all years)
• 20.5mm solid for Type R (all years)

Aftermarket rear bars go up from there and are as follows (links provided as well):

• Eibach - 22mm or 25mm | tubular | 2 adjustment holes | billet brackets (25mm only)
• RV6 - 25.4mm (1") | tubular | 3 adjustment holes | billet brackets
• Whiteline - 22mm or 26mm | solid | 2 adjustment holes | billet brackets (26mm only) | 26mm includes end links
• Karcepts - 25.4mm (1") | tubular (2 options) | 5 adjustment holes | billet brackets | solid bushings
• Cusco - 22mm | solid | 2 adjustment holes | billet brackets
• Progress Technologies - 21mm or 22mm/22mm | solid | 1 or 3 adjustment holes | reinforced brackets | adjustable 22mm version includes end links
• aFe - 25.4mm (1") | tubular | 2 adjustment holes | billet brackets | Only sold with front bar
• Hardrace - 22mm | tubular | 1 hole | no brackets

Due to the drastically different front suspension setups the Type R front sway bar does not interchange with the rest of the Civic lineup. The stock front bar sizes are as follows (for 10th gens):

• 25mm tubular (4mm wall) for LX (2016-2021)
• 25.5mm tubular (4mm wall) for EX (2016-2018) Touring coupe (2016-2018), all hatchbacks (non Type R, 2016-2021)
• 26.5mm tubular (4.5mm wall) for Touring (all years), EX (2019-2021), all trims except Si and Type R (2022+)
• 27mm tubular (4.5mm wall) for Si (all years)
• 29mm tubular (5mm wall) for Type R (all years)

Non Type R aftermarket front bars go up from there and are as follows:

• Eibach - 29mm | tubular | 1 hole
• Whiteline - 27mm | solid | 2 adjustment holes
• Hardrace - 28mm | tubular | 2 adjustment holes

Type R aftermarket front bars go up from there and are as follows:

• Eibach - 32mm | tubular | 1 hole
• Cusco - 30mm | solid | 1 hole
• aFe - 32mm (1.25") | tubular | tubular | 1 hole | Only sold with rear bar
• Hardrace - 30mm | tubular | 2 adjustment holes

And that sums up everything you need to know about sway bar for your 10th or 11th generation Civic. If you think we missed anything let us know down in the comments. Be sure to check out our social medias for new product announcements as well as more of these informative blog posts that specifically look at the Civic platform. Thanks for reading along!

- Austin and the Wunderladen Racing team