Re: Duke, et al. Bias Ply Tires...
Whatever tire safety or quality standards that existed prior to DOT standards were either industry promulgated or left to the manufacturer, so it's tough to compare DOT tires with pre-DOT tires other than personal experience, however, I stand by my contention that the current minimum DOT standards are INADEQUATE.
A tire that is only designed to survive 85 MPH at max design load and pressure could disintegrate at 60 MPH if a slow leak allows pressure to drop below the minimum required to sustain the load and speed in prevaling ambient temperature condtions. Plus you have the normal statistical distribution. Just because a given make/model tire passes a specific standard does not mean all of the like tires have the same durabililty. It's all about SAFETY MARGIN, and the only thing that keeps our cars on the road are those four little contact patches. If one of them suddenly evaporates, loss of control and its potentially disasterous consequences are a potential result. You only need to recall the recent Ford Explorer fiasco to understand the possibilites. Those tires only met minimum DOT standards and subsequent manufacturing defects due to shoddy quality control yielded tires that would not even pass the minimum durability certification test. The cost in lives was over 200!
I keep harping about high speed rated tires because (in almost all cases) "H" or above speed rated tires have a spiral wound nylon cap belt that will nearly always prevent the tire from disintegrating if there is an internal structural failure due to excess head buildup or a manufacturing defect. A three tire structural failures that I have personally experienced all occurred during track events and in each case the tire stayed in one piece and held are due to the presence of the spriral wound nylon cap belt.
On a long stretch of high speed highway driving a slow leak can develop and the tire can disintegrate suddenly and catastrophically before the driver realizes there is a problem. This can occur to even informed and astute drivers who are senstive to their vehicles handling characteristics.
It's the same reasoning why we Maganflux inspect crankshafts and connecting rods or replace or "upgrade" any parts (like early 327 connecting rods) that are remotely suspect during an engine rebuild. We don't want it to blow up, even if we thing we will never rev to 6500. Likewise, nothwithstanding the handling benefits, it is wise to procure the highest quality tires to reduce the possibility of a failure, which could lead to a serious accident - significant damage to the car, personal injury to us or our passengers, or even death.
I would never, ever install anything less than a "H" speed rated tire on any vehicle I own, other than, perhaps, a "period" tire that I would only use for shows and local driving. For general driving and road trips I have modern high speed rated tires that allow me to drive my cars to their maximum potential, traffic conditions permitting, and not worry about the possiblity of low quality tire disintegating.
For those who just want to show their cars and just drive to local shows or trailer them to shows, bias reproduction tires are fine, but if you want to DRIVE your car, especially in a manner that sports cars are designed to be driven, then don't shortchange yourself by installing anything less than the highest performance/speed rating tires available.
Duke
Whatever tire safety or quality standards that existed prior to DOT standards were either industry promulgated or left to the manufacturer, so it's tough to compare DOT tires with pre-DOT tires other than personal experience, however, I stand by my contention that the current minimum DOT standards are INADEQUATE.
A tire that is only designed to survive 85 MPH at max design load and pressure could disintegrate at 60 MPH if a slow leak allows pressure to drop below the minimum required to sustain the load and speed in prevaling ambient temperature condtions. Plus you have the normal statistical distribution. Just because a given make/model tire passes a specific standard does not mean all of the like tires have the same durabililty. It's all about SAFETY MARGIN, and the only thing that keeps our cars on the road are those four little contact patches. If one of them suddenly evaporates, loss of control and its potentially disasterous consequences are a potential result. You only need to recall the recent Ford Explorer fiasco to understand the possibilites. Those tires only met minimum DOT standards and subsequent manufacturing defects due to shoddy quality control yielded tires that would not even pass the minimum durability certification test. The cost in lives was over 200!
I keep harping about high speed rated tires because (in almost all cases) "H" or above speed rated tires have a spiral wound nylon cap belt that will nearly always prevent the tire from disintegrating if there is an internal structural failure due to excess head buildup or a manufacturing defect. A three tire structural failures that I have personally experienced all occurred during track events and in each case the tire stayed in one piece and held are due to the presence of the spriral wound nylon cap belt.
On a long stretch of high speed highway driving a slow leak can develop and the tire can disintegrate suddenly and catastrophically before the driver realizes there is a problem. This can occur to even informed and astute drivers who are senstive to their vehicles handling characteristics.
It's the same reasoning why we Maganflux inspect crankshafts and connecting rods or replace or "upgrade" any parts (like early 327 connecting rods) that are remotely suspect during an engine rebuild. We don't want it to blow up, even if we thing we will never rev to 6500. Likewise, nothwithstanding the handling benefits, it is wise to procure the highest quality tires to reduce the possibility of a failure, which could lead to a serious accident - significant damage to the car, personal injury to us or our passengers, or even death.
I would never, ever install anything less than a "H" speed rated tire on any vehicle I own, other than, perhaps, a "period" tire that I would only use for shows and local driving. For general driving and road trips I have modern high speed rated tires that allow me to drive my cars to their maximum potential, traffic conditions permitting, and not worry about the possiblity of low quality tire disintegating.
For those who just want to show their cars and just drive to local shows or trailer them to shows, bias reproduction tires are fine, but if you want to DRIVE your car, especially in a manner that sports cars are designed to be driven, then don't shortchange yourself by installing anything less than the highest performance/speed rating tires available.
Duke
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