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Well, I don't know why Hoosier would make such a large selection of Race Rubber that's bias ply if they didn't perform well. I know we have them on our Formula SAE car, but that might be due to cost more than peak grip.Jersey Tom wrote:If by "you cant slide the car as much" they mean you cant be a sloppy driver, then yes.
Other than that I can't imagine any reason to go back to bias ply tires. There's no way it will return to high level motorsport.
Most racing radial tires are closer to a belted bias ply tire than a passenger car radial tire. This gives the racing radial tire traits from both bias & radial tires (good feedback & higher breakaway traction). Which tire is best for you, it depends on your needs. The bias tire is good for applications where negative camber is limited, but only if a wide enough rim is available. Radials are good where transient handling is primary concern, and adequate negative camber is available.
Bias Ply vs. Radial performance
Bias ply tires differ from radials on the following items.
* Static negative camber requirements are less, usually about 1 to 1 1/2 degree negative is sufficient.
* Rim width selection is more critical, because the tread face is flexible, the rim helps support the tire. The rim width should be as large or larger than the section width of the tire.
* Air pressure can not be used to reduce sidewall flex (rollover). Excessive air pressure will cause the tread face to bulge, reducing the contact patch.
* Bias ply tires give more warning (than radials) about traction limits and have excellent feedback of what the contact patch is doing.
* Bias ply tires operate at larger slip angles than radials. This larger slip angle is what makes bias tires feel sloppy on initial corner turn in. What this means to the driver, you have to 'lead' the corner more to account for the slip angles.
* Because of how bias tires react to cornering loads, the tread can be thicker than radial tires.
Radials differ from bias ply on the following items.
* Radials generally need more static negative camber than bias tires.
* Radials generally provide more breakaway grip than a bias tire.
* Radials give less warning before 'breaking away'. This causes radials to be harder to drive at the limit.
* Air pressure can be used to reduce sidewall rollover, without having the tread bulge like a bias tire. The may allow you to use a larger sized tire.
* Radials are usually heavier than bias tires due to the over wrap plys.
* Radials operate at lower slip angles than bias ply tires. The is the main reason Radials have better transient response than bias tires.
Yea, I won't argue that radials are here to stay and offer better grip when setup properly. But some people do like a forgiving tire that isn't camber limited, and that's why bias ply are nice for autocross tracks. Personally, it works out good for me because I don't like to run a lot of negative camber on my daily driver so I can put on a set of bias-ply R-compound hoosiers (not DOT legal of course) and run my 'street' suspension setup on the track with little compromise.Jersey Tom wrote:Look at any top-end motorsport.. Formula 1, ChampCar, GP2, hell even NASCAR. All on radials. There's a reason for that.
And FYI even in FSAE, Michelin and now Hoosier have been quietly developing radials for the competition.
Going back to bias tires in F1 would be like saying "Well lets go back to not having aero. Sure we wont have as much peak grip but the car will be a little basic and easier to drive"
Roland Ehnström wrote:Here's an awesome clip of Patrick Depailler driving a Tyrrell on a very wet Montreal track in 1978, on what to me looks like (bias ply) SLICKS, even though the commentator (Murray Walker) sais they are rain tires. I don't know why he would go out on slicks in these conditions - maybe he just wanted to show off for the camera?! But anyway, this clip shows the kind of driving skill that I wish we could see more of in modern formula one: http://www.youtube.com/watch?v=KqZBJCFS_Ng Crank up the volume!
He is indeed on rain tyres, you just don't see it from the low quality youtube video. The grooved tyres are very apparent on the dvd.Roland Ehnström wrote:I Here's an awesome clip of Patrick Depailler driving a Tyrrell on a very wet Montreal track in 1978, on what to me looks like (bias ply) SLICKS, even though the commentator (Murray Walker) sais they are rain tires.
Of course they were going slower in those days, MILES slower! The cars had so much less grip in every possible way, especially in tires and aerodynamics, and they had less than 500 hp compared to almost 800 today. (And that Tyrrell didn't have ground effect, only Lotus had ground effect in 1978.)ginsu wrote:To be honest, while that is a good clip, it looks like he was going pretty
slow to me, at least compared to today's speeds. Also, he may have had full ground effects with side skirts, too.
Canada
Fastest Lap 1978: Alan Jones 1'38.072
Canada
Fastest Lap 2005: Kimi Räikkönen 1'14.384
I quite agreeRoland Ehnström wrote:But the point I'm trying to make is that high SPEED doesn't in itself provide good racing. In fact, I think F1 cars today are even a bit too fast to provide good racing and a good show. They're even so fast in the corners that it sometimes looks completely unrealistic. With lower cornering speeds, drivers could easier run side by side. With longer braking zones, drivers could easier outbrake another car. With less downforce, awesome bends like Eau Rouge, 130R, and so on, could not longer be taken flat out, which would make them much more challenging again. With lower cornering speeds and higher slip-angles (bis ply tires!), the audience and TV-viewers could easier see what the drivers do, and why. And so on...