I first met Bret Voelkel back in 1990, when he was operating the support truck for Blower Drive Service. It was obvious that he was a knowledgeable guy and a real gearhead, so it didn’t surprise me at all when, years later, I found out that he had started his own company. Only it wasn’t about superchargers, but rather air springs for hot rods.
That was in 1996, when air bags for cars, or hot rods at least, were in their infancy.
Sure, big rigs and heavy equipment had used them for years, the Lincoln LSC and some other luxury cars had air springs, and drag racers used air bags inside their rear coil springs (or on top of leaf springs) to control suspension preload, but not many people thought to replace the entire spring assembly with an air bag.
Bret’s company, Air Ride Technologies (which changed to RideTech in 2008) changed the face of hot rodding.
Today, airbags are widely used, from the sport truck set that likes to “lay frame” to customs and hot rods that want to make sure the stance is perfect, the ride is decent, and there’s enough suspension adjustment to get over speed bumps and driveway approach angles.
Somewhere along the way, Bret got caught up in the hardcore pro touring scene that focused on handling performance combined with trick parts that look good.
As part of that experience, he got neck-deep in autocrossing and began to sponsor the performance handling events such as the Goodguys autocrosses and the Optima Ultimate Street Car Invitational, as well as all of its qualifier events.
This was the perfect arena to showcase that his air springs can work well in a performance situation, and it also got him looking at the whole of a car’s suspension. That led him to talk to his friends at Fox Shocks, who had been supplying many of the shock cartridges for his air springs, and they worked together to develop coil-over shocks for the performance aftermarket. They also work just well, if not better, on street rods.
RideTech’s coil-overs are made entirely in the USA, including the springs, and there is a lot of science in the design. This story will go into detail about each coil-over design, and offer some recommendations on usage.
What Is A Coil-Over?
Just what it sounds like. Traditional suspensions use shocks separate from the springs, whether it’s a set of friction shocks on a solid-axle Model A or a shock inside (but not connected to) a coil spring on a ’69 Camaro.
A coil-over puts the shock and spring in one linear unit; the shock body is threaded and the spring is held in place around the shock with collars/mounts that allow for significant adjustments in ride height, something you can’t do on a traditional suspension without changing the spring and/or other suspension settings.
Just as with regular shocks, there are several types of coil-overs. The most economical is a non-adjustable design, with factory preset compression (bump) and rebound (extension) valving.
Single-adjustable shocks allow you to adjust the stiffness of the shock’s rebound function, a double-adjustable allows adjustment of both bump and rebound, and then there’s a triple-adjustable that includes an additional high-speed bump setting.
The combination of tires, shocks, and springs are what dictates the car’s handling and ride quality, and of those three parts, the shocks are primarily responsible for the harshness of the ride quality.
A stiff spring and a stiff shock might handle well on a smooth surface, but that combination will knock your fillings out on a typical pothole-filled city street. In many cases, the harshness of a stiff spring can be tamed down a bit with a soft shock.
About RideTech’s Coil-Overs
RideTech didn’t just decide to build shocks via trial and error. They have years of association with Fox Shocks, who provide the shock cartridges to RideTech, but also provide shocks to the OEs (the Ford Raptor truck comes stock with Fox Shocks, for example), the military, and to the bicycle industry, so they know what they’re doing when it comes to trick shock technology. They build shocks for bicycles?
Musclecar guys like the single-adjustable shock. I’ve got some fairly quick cars that are real serious about road course and autocross racing that are using the single with really good success.
As Bret said, “If you think about it, you’ve got a 25-pound machine with a 150- to 200-pound rider, so you need a wide range of adjustment to accommodate that. There’s some serious rocket science going on in bicycle shocks that’s for sure! Car shocks are easy compared to that.”
The RideTech shocks are all a monotube design, which is far more efficient than the twin-tube design of a cheaper shock. The monotube shock uses a bigger piston for much better oil control, which translates into a better ride and more consistent performance. The shock body is a one-piece impact-forged tube that’s hard-coat anodized for long-lasting durability and appearance, and the guts are state-of-the art shock technology.
A big 5/8-inch hardened and precision-ground shaft, Teflon piston wiper, Kevlar-lined bearings…take our word for it, it’s all top-quality stuff. The 2 ½-inch (diameter) springs are made for RideTech by its neighbors at HyperCo in Indiana, and come in a bunch of different rates (stiffness) and lengths.
The non-adjustable coil-overs are preset from RideTech for the best ride possible while still maintaining as much handling performance as possible.
“The street rod guys gravitate toward the non-adjustables because they usually don’t know how to adjust the thing anyway, and they don’t want to,” Bret told us. “They just want something that goes on the car and makes it ride good so their wives don’t bitch about how the car rides.”
The non-adjustable is the least-expensive coil-over in the RideTech line, but according to Bret the price doesn’t seem to be as much of a consideration within the street rod community—it’s the ride quality that matters.
“Most of them are running around with an old worn-out Aldan or Strange shock, that’s way too short with too stiff a spring on it, and the valving is 40-year-old technology.
When we give them something a little longer with the appropriate spring rate, and the monotube design, the ride quality is, well, it’s really tough to describe the ride difference until you’ve experienced it. It’s night and day,” Bret said.
When your car hits a bump, the wheel/tire moves up and the shock compresses. When the car comes off the bump, the shock extends, or rebounds. In the single-adjustable design, this extension can be adjusted for its stiffness of movement. A stiffer adjustment means the shock has more resistance at moving, and the ride will be harsher.
A softer setting means the shock extends easier, which is generally rewarded with a softer ride. There are about a million variables involved here, but that’s the gist of a shock setting.
The bump/compression is set at RideTech and is non-adjustable, but there are a whopping 24 levels of adjustment on rebound. A double-adjustable shock, like many you’ll see in the aftermarket, allow adjustment of both bump and rebound settings.
Non-Adjustable: Least expensive of the RideTech shocks; greatly improved ride quality; a bolt-it-on-and-forget-it deal; the most popular coil-over for the street rod market.
Single-Adjustable: Allows 24 different settings for rebound; the most popular shock for the muscle car market.
Triple-Adjustable: Adjustable settings for rebound and two different levels of compression, high- and low-speed. Aimed more at the high-end market, these are great shocks for open track cars, serious autocross racers, or even the street guy that likes to dial in his car to perfection.
Select Coil-Over: In reality, 99% of people don’t need more than one adjustment in a shock: firm and softer-than-firm. These trick coil-overs allow you to cycle through those two settings without ever removing your seatbelt.
RideTech skipped right over the double-adjustable design and went with a triple-adjustable, since most other shock companies have flooded the market with doubles, and they wanted to be different. As Bret said, “The price of the triple isn’t a whole lot more than the double, and it gives us something better than what everyone else has.”
Where is the third adjustment? The triple has the traditional adjustability for bump and rebound, 24 adjustments in each direction, and it features an additional level of compression adjustment, a high-speed and a low-speed circuit. The low-speed circuit is similar to other double-adjustables in that it tunes the handling transitions, curves, dips, and things like that. The high-speed circuit adjusts, via 12 different settings, the impact harshness, anything above about a 15- to 20-inch-per-second piston rod velocity.
An example of when that could be useful was provided by Bret; “We were running a car at Nashville last year, and the transition from the straightaway to the infield was about a 10-degree transition, and it bottomed the shit out of the car. So I dialed about six clicks of high-speed compression into the car and it resolved that transition, but didn’t effect the car on the rest of the track.”
While it’s probably overkill for the street, that high-speed adjustment could prove handy when driving on really rough roads with potholes and other crap making the suspension cycle rapidly. The triples, and most other monotube shocks, come with a remote reservoir that contains the gas chamber, compression valving, and adjusters. This remote reservoir increases oil capacity and cooling, and also allows the shock body to be short enough to fit a variety of applications. Plus it looks racy, which is nice.
Bret told us, “A lot of people come in asking about the triples and I probably spend more time talking them out of the triple than I do into it. The triple is a wonderful piece and is state-of-the-art…I use the analogy of electronic fuel injection. BigStuff3 is really cool and it’ll do everything you could possibly ever want it to do, but you have to know what you want it to do. But, with a Holley or an EZ EFI system, they’ve made a bunch of those decisions for you, and for 99% of the people it does everything they want it to do. So why spend the extra money and go thru the extra hassle?”
Still, there are a lot of people running the triples in road course, autocross, and even some drag racing action. If you like tuning your car to the Nth degree, these are the shocks you should consider.
Have you driven one of those newer cars with cockpit-adjustable shocks? At the flip of a switch, you can change the shock valving from firm to soft. Pretty cool, right? The Select series of coil-overs are RideTech’s aftermarket version of that.
It’s a steel-bodied monotube design like the other RideTech shocks, but it comes with two sets of internal valving that you can change between a soft, compliant, cruise mode and a firmer sport mode, with a switch mounted in the car.
They’re a few hundred dollars more (each) than the single-adjustable shocks, and must be used with RideTech’s controller, which is another $100, but they’re the easiest to adjust on the fly.
There is also an optional control switch that allows you to change the valving of the front and rear shock pairs independently.
The Conclusion on Coil Springs
As mentioned above, the coils for RideTech’s shocks are made by HyperCo in Indiana, making these 100% American-made coil-overs. When buying the coil-overs, first you need to pick which model shock you want, as described above, then choose the spring, and RideTech will package it together for you.
The springs are available in a huge variety of lengths and rates, from 6- to 14-inches, and from 125 to 800 lb/in. RideTech’s website has a spring rate calculator and a vehicle weight table to help you determine the right springs to get. You’ll need to do some measuring of your car, but it will get you on the right track.