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Building a Better Foundation

The Roadster Shop Breathes New Life Into Tri-Five Chassis

Dec 9, 2003

To be honest, many shops around the country wouldn't be in business if it weren't for late-model IFS swaps and rearend updates--that's the bread and butter of their whole gig. At the same time, there are many owners (and even builders) who would prefer to not have to go through the hassle of whacking off the old front suspension and grafting on a new clip of crossmember, not to mention the additional chores of bringing the rear suspension up to par. This includes the popular Chevy Tri-Five crowd that has been slowly but surely migrating into the custom rod arena. Problem is, there aren't many vehicle-specific aftermarket chassis on the market worth their salt. (For instance, having to locate and attach new body mounts isn't the easiest task in the world.)

Bill O'Rourke at the Roadster Shop, Inc. in Elgin, Illinois, saw the need for not only a user-friendly '55-57 Chevy chassis, but also one that was more adaptable to modern componentry. Not your average square-tube frame, this platform is constructed to physically resemble the factory GM foundation it is replacing, but with two main advantages: lowering the car 4 inches (without affecting suspension travel!) and allowing the use of larger/wider wheels while maintaining a proper turning radius. The drop in ride height (actually car height--like channeling without the channeling!) is achieved by lowering the chassis center main rails, which are constructed out of 4x4 1/4-wall tubing, while narrowing the front frame horns, which are constructed out of 1/8-inch mild steel but still retain the factory appearance and mounting tabs (bumpers, core support, etc.). Each chassis also comes complete with body mounting tabs that require no modifications for remounting your sedan or wagon--this is a literal "bolt-on" deal!

Baseline, the complete chassis retails for $7,995, and that gets you pretty much everything besides engine, trans, and rollers. Starting with the front, the package includes a Heidt's SupeRide II IFS complete with 11-inch disc brakes, rack-and-pinion, sway bar, and Aldan coilovers. Upgrades to chrome-plated and stainless components are also available. Like their hot rod chassis, Roadster Shop equips these with 1 1/2 x .120-wall tubular center crossmembers, complete with drop-out trans mounts. The rear suspension consists of a standard 9-inch Ford housing (with all new parts, excluding third member), 11-inch drums, triangulated four-bar, Aldan coilovers, and sway bar. Third member options range from standard-type to Posi, in a wide variety of gear ratios. And while engine mounts are included, that doesn't just mean your run-of-the-mill SBC mounts, either. Roadster Shop can equip the chassis with any engine/trans mount combo the customer desires...and set them up so no firewall modifications will be required. Other notable options include mechanical clutch linkage that will allow the use of the stock swinging clutch pedal, rack location that will allow the use of a stock steering column (or aftermarket), and Wilwood disc brake upgrade.

While en route from Des Moines to Columbus (the long way), we stopped by O'Rourke's Roadster Shop to check out his new chassis for ourselves. For the mid-'50s Chevy guy looking to take his car or wagon to the next level with minimal effort (and not have to take a second out on the house), this is the way to go. Check it out for yourselves.


Which would you rather work with--a stock '55-57 Chevy chassis, with its antiquated suspensions, or a brand-new, modernized Roadster Shop chassis with all the bells and whistles?

No cutting, splicing, or welding to do...just add the finishing ingredients, set 'er a-roll, and drop your body on and go!

This new chassis is also proof that you can lower your car 4 inches without affecting any ride characteristics or having to cut your floor out!

The Roadster Shop dropped the center main rails to accommodate the drop and also narrowed the front section to allow the use of wider/taller wheels without sacrificing turning radius--and it still retains all the factory mounting points.

Standard equipment on the '55-57 chassis: 9-inch Ford rearend with all-new components (third member optional), triangulated four-link, and Aldan coilover shocks. For those wanting a bit more flash, chrome and stainless upgrades are available, as well as Wilwood disc brakes (front and rear).

The goal was to retain as much of a factory appearance with the framerails as possible, and the Roadster Shop did just that. The frontend is anything but OE '55-57 Chevy--try Heidt's Superide II complete rotor-to-rotor IFS.

The frames are not built in a mass-production manner, rather, each one is pieced together the old-fashioned way--by hand, no CNC'ing involved.

Steel sheet is used for the front and rear frame horns, which attach to the 4x4 square-tube center main rails. Chad Glasshagel (background) shows Jeremy Gurber how things are done.

Unlike your average full square-tube chassis, the Roadster Shop's offering is precisely bent with no sharp edges.

Along with offering a nicer looking frame, the seamless front horns are narrowed for improved steering with today's larger-diameter wheels tucked up in the wheelwells.

Each chassis also features a tubular center crossmember, very much like that used in a '32-34 Ford chassis, complete with a drop-out tranny mount. Among other things, this makes exhaust routing easier.

Using a rotisserie jig to assemble each chassis one at a time ensures each one gets the attention it deserves--no mass-production here. Having many '55-57 Chevy resources available (stock chassis, various body components) allows the Roadster Shop to construct frames with special provisions, such as varied engine/trans combos.


Roadster Shop, Inc.
Elgin, IL 60120

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