I-Beam and Tube Axles - On The Straight And Narrow

Borgeson manufactures Vintage Chassis Works tube axles, with forged steel ends for maximum strength. Available with or without spring perch bosses, and drilled with bosses, all three versions have a 4-inch drop, are designed to work with '37-48 Ford spindles, and are available in 46-, 47-, and 48-1/2-inch kingpin center widths, though custom widths are available, too.

Magnum's dropped tube axles accept '37-48 spindles, as well as their own, and are available in a 4- or 5-inch drop. They use 1018 forged ends with a 2-inch diameter, 1/4-inch wall 1018 seamless tubing, and have 1- to 1-1/4-degrees positive caster built in. A variety of widths are available, with custom widths at extra cost, and all are available plain or chromed, and with 2- or 2-1/4-inch perch bosses. The I-beam axles are also available in 4- and 5-inch drops, in four widths to fit '28-48 Fords. Again, both perch-boss sizes are available, as are the choices of plain or chrome finish.

Super Bell introduced its first dropped tube axle in 1975 and has since gone on to develop both tube and I-beam axles, including aluminum I-beams. The I-beams are available drilled or un-drilled with the ends filled or standard. Cast from high-strength ductile iron, Super Bell's I-beams are designed to accept '37-48 Ford or Econoline spindles. The company's 2-inch-diameter tube axles accept the early Ford spindles and are available in standard widths of 46 1/2 and 49 inches kingpin-to-kingpin center with perch centers of 36 1/2 or 34 inches, as well as perch boss thicknesses of 2 or 2 1/4 inches, though custom axles can be ordered with widths between 42 and 49 inches, a choice of drop distances, and spindle applications, including Chevy. For those wanting something a little different, Super Bell's aluminum I-beam comes in a 4-inch drop, with 34-inch perch centers, 2-1/4-inch perch bosses for Ford spindles, and a 29-inch spring. It's available fully polished or just highlighted, and comes with a drilled option, including the neat oval drilled version.

Speedway Motors' dropped tube axles are available in many styles, such as 4- and 6-inch drops, '37-48 Ford, or '49-54 Chevy spindles, spring-behind or spring-over, stainless, plain or chrome, and in any combination of the above. They have a 2-inch diameter and 1/2-inch wall thickness, and 48-inch-wide kingpin-to-kingpin center, designed for use with a 26-inch spring. The straight-axle can be had with or without spring pads, for Chevy or Ford spindles, and will soon be available in varying widths in addition to the standard 46-inch kingpin centers.

The GT2 line of stainless steel components offered by SO-CAL Speed Shop now includes an investment-cast 316 stainless steel axle designed to look like a 4-inch dropped I-beam with filled ends. At 46 inches wide, it's available fully polished or as-cast, and it can also be had drilled.

Not strictly a straight-axle, though it was once, here's something a little different. Fatman Fabrications offers this Vintage IFS system, which is essentially an I-beam split in the center. It preserves the look of the axle but offers ride and handling on par with a true double A-arm IFS. There is some camber change, but as the body rolls out of the turn, the axles lean into it like a bike. There is absolutely zero bumpsteer. With the 4- to 5-inch travel common to straight-axle shocks, camber change is limited. The camber rate is about 20 percent faster than an IFS.

Total Cost Involved Engineering tube axles feature forged steel ends with a 2-inch diameter and 1/4-inch wall tube. The axle, designed to fit for '28-34 Fords, is available with 46- or 48-inch kingpin centers. As with most manufacturers mentioned here, Total Cost Involved can supply the remainder of the components required to build a complete frontend.

Another in the "not quite a straight-axle but almost" category, the DominAtor from Flaming River/Dominator Motorsports is a dual-pivot straight-axle with rack-and-pinion steering that offers improved suspension performance over a regular straight-axle. The use of the dual-pivot, independent twin-arm design delivers improved front suspension travel, while eliminating bumpsteer inherent with the straight-axle suspension. The DominAtor axle system uses early Ford spindles. The twin arms have been deliberately designed to retain the appearance of the time-honored straight-axle, with the steering rack hidden as much as possible behind the assembly. The DominAtor is offered in a standard 48-inch track with a 5-inch drop and coilover shocks, is available in a narrowed (or pinched) design, and includes a wishbone or four-link suspension with manual or power steering. It can be either installed into new construction or retrofit into existing cars or trucks.