DOCOL R8: The State of the Art in Advanced High-Strength Steel

A few years ago, while attending PRI (the Performance Racing Industry trade show in Indianapolis), the guys at CMS Performance were introduced to a newly-developed steel tubing product called Docol R8. It was designed to replace 4130 Chrome-Moly -- a World War II-era product -- in race car chassis and safety cage construction. They were intrigued. 4130 has always had its drawbacks as a metal used for impact absorption. It tends to get brittle when welded, and it lacks ductility (the ability to sustain plastic deformation under tensile stress before failure.)

Docol is a modern, engineered Dual Phase Advanced High-Strength Steel (AHSS), replacing 4130 as the state-of-the-art material for race car chassis and safety cage manufacturing. CMS found that racing fabricators were switching to Docol R8. Engineered specifically for motorsports applications, Docol R8 is an improvement over 4130 in every way:

• Docol R8 is considerably stronger than 4130 CrMo. Tensile Strength of 116,000 psi vs 95,000 psi, Yield Strength of 100,000 psi vs. 75,000 psi.
• Docol R8's heat-affected zone (HAZ) is much smaller, meaning much less joint embrittlement from the heat of TIG welding.
• Docol R8 has a higher resistance to fatigue.
• Docol R8 is much more tolerant of heavy fabrication (such as tube bending and forming).
• Docol R8 is far more dimensionally consistent, with tube diameter variance of 0.3% vs. 10.0% in 4130 and wall thickness variance less than 1/3 that of 4130.

So after extensive research, consultation with testing engineers, and discussion with professional race car fabricators, Competition Motorsport was the first major manufacturer to transition fabrication of all our bolt-in roll bars and harness bars from using 4130 CrMo to Docol R8.

That was in 2018, and five years later Discovery Parts and CMS have had nothing but great experience with, and feedback about, Docol R8. Fortunately, we haven't had many customers tell us about accidents they've had that put the strength of their CMS Performance roll bar to the test. But we have had a couple. In one case in particular, a customer told us his CMS roll bar saved him from significant injury. He was hit broadside at an angle just behind the driver seat -- basically, right into the meat of the main hoop of his roll bar -- and the offending car didn't protrude into the cockpit even an inch further.

Competition Motorsport drivers have been amazed at the strength of Docol R8 under race conditions. Having had their fair share of race car "rubbing", the chassis structures fabricated from Docol are always amazingly intact.

Is Docol more expensive than 4130? A little. But CMS Performance prices have remained unchanged. They believe in delivering a superior product at a competitive price, and that very much fits Discovery Parts' philosophy. It gives us an edge, and it gives our customers an edge. CMS Performance designs and manufactures every roll bar in-house, starting with straight bar stock and ending up with a beautifully TIG-welded roll bar. They powder coat each one in their professional powder booth, on-site. And they're proud to use advanced materials like Docol R8.

None of it is farmed out. When CMS puts their name on a piece of safety equipment, and we ask you to bolt it in your car and take it to the track, we don't take chances. The result is superior design, quality, and service, that you simply can't find anywhere else. You can pay more for a roll bar, but you can only get the best from CMS Performance. Check out all the CMS Performance Roll Bars here.

And, as always, feel free to give us a call at (888) 748-7223 or drop us an email if you want more info about Docol R8 vs 4130 CrMo, and if you want to discuss what roll bar is right for you!