 Tauranac built the BT19 around a mild steel spaceframe chassis similar to those used in his previous Brabham designs . The use of a spaceframe was considered a conservative design decision ; by 1966 , most of Brabham 's competitors were using the theoretically lighter and stiffer monocoque design , introduced to Formula One by Lotus during the 1962 season . Tauranac believed that contemporary monocoques were not usefully stiffer than a well @-@ designed spaceframe and were harder to repair and maintain . The latter was a particular concern for Brabham , which was the largest manufacturer of customer single @-@ seater racing cars in the world at the time . The company 's reputation rested in part on BRO – effectively the official ' works ' team – using the same technology as its customers , for whom ease of repair was a significant consideration . One mildly novel feature was the use of oval @-@ section , rather than round , tubing around the cockpit , where the driver sits . In a spaceframe or monocoque racing car , the cockpit is effectively a hole in the structure , weakening it considerably . For a given cross sectional area , oval tubing is stiffer in one direction than round tubing . Tauranac happened to have a supply of oval tubing and used it to stiffen the cockpit area . The car weighed around 1250 pounds ( 567 kg ) , around 150 lb ( 68 @.@ 0 kg ) over the minimum weight limit for the formula , although it was still one of the lightest cars in the 1966 field . The race starting weight of a 1966 Brabham @-@ Repco with driver and fuel was estimated to be around 1 @,@ 415 lb ( 642 kg ) , about 280 lb ( 127 kg ) less than the more powerful rival Cooper T81 @-@ Maseratis . 
