Big Wheels < Small Wheels

fanfoy wrote: Yes and no I guess that should reassure the ones complaining that you can't find 13" tires anymore. If you can still buy tires for those cars, I cannot imagine it is THAT hard to find a 13" tire. Heck, coker tire has 29 choices just in radial.

Ha! Maybe the fad was 13" wheels and we're just getting back to normal now!

I bet it was helpful to have large outer diameter wheels/tires when those car were new because the roads were so rough. Like the difference between a 26" wheel mountain bike and a 29er.

EDIT: I think we were just joking Vigo (hence the eye-wink-smiley) sorry if interjected something into the thread, I haven't actually just read it through. Just commenting on fanfoy's old-timey photos.

There's less demand for them because the OEMs stopped putting them on cars. Not because people necessarily didn't want them. I had a Honda Civic with 13" steelies. Great car.

Now, 13" whitewalls are getting really hard to find in a decent radial for a reasonable price, but I will grant you that WW tires are possibly not as much in fashion currently as they were in the 1960's. ;-)

I'm not sure why we've seen the "U" shaped curve of wheel diamter over the past 100 years. Cars went from large, spoked wheels down to 13 and 14" steelies and are now going back up again. Fashion? Trend? Or a legitimate engineering reason?

I think there is genuine logic behind it. 100 years ago, the roads and the suspensions were rough. So a large wheel with a large sidewall made a lot of sense. Than in the late 30s, cars started to have IFS, and the roads got smoother and more often paved. So the manufacturers saw they could get away with much smaller wheels while retaining the same comfort level.

I think today, it has a lot to do with braking performance. As the cars are getting more and more powerful, you need bigger brakes to slow them down. And it's not like back in the days when you could slap tiny 10" drums at all four corners of a 5000 lbs land yacht. Now a days, more and more regulations (like TUV) ask the braking performance to be on par with the straight line performance.

Wheel and tire construction methods are why things started the way they did. Remember, tires werent even pneumatic in the beginning, and car wheels were built similarly to wagon wheels.. You cant pull off a 235/75/15 of solid rubber without it weighing 100 lbs. You cant put a non-pneumatic tire on a small rim without horrendous ride and inadequate ground clearance, either.

Also, i have never had a car with 13" wheels that had good brakes, ever. Sure, ALL of them had brakes that were good enough that normal people wouldnt notice the difference, but none of them had brakes an enthusiast would like. Even my insight which came with 14" wheels (not sure if 13s would clear the brakes or not but i suspect yes) probably could not make one 100-0 panic stop without me having to buy another set of rotors. I admit that that is outside the envelope of normal use, but it's one reason why i cheer the continual upsizing of brakes. One wonders: if germany did not have the autobahn, would german cars have the reputation they have today? I doubt it. But maybe we would have more 13" wheels!! Fair trade?

Wheels got smaller because the cars started getting larger and needed a wider contact patch. With the tire manufacturing technology of the time for a tire to get wider it needed a taller sidewall at the same time.17 or 18 inch wheels with a 6-8 inch tread width would get upwards of 34" tall with the bias ply or early radial tires available. Go down to a 13 or 14" wheel and packaging gets easier with the same widths.

I have an old article from a car mag in the 70's that talks about waiting impatiently for the super low profile 60 series tires that had been promised for years so they could take advantage of some 8" wide wheels.

My Precious.

15x6 mx6 gt? I recommend 205/55/15. Or if you can slam it like a boss, 205/50.

205/50 would be crappy on gearing for that car unless you swapped the 3.0 Probe final drive.

I like the 225/50/15 fatty sidewall option. Those are my wheels. I also have a NIB set in the 90-92 style. They will be used one day.

JamesMcD wrote: I like the 225/50/15 fatty sidewall option. Those are my wheels. I also have a NIB set in the 90-92 style. They will be used one day.

That size looks awesome on the FC BBSs, that's what eric was running.

Those are also wide enough so it works halfass decent. I wouldnt run 225/50 on a 6.0

Small cars had small wheels to help with acceleration. A small 1960s or 1970s car with 50 to 75 (gross) horsepower would have been even slower (acceleration wise) if it had to turn 15 inch wheels (few car had bigger at the time). Packaging, cost and technology limited tire size (diameter and width) at the time. To me, a small car with big wheels looks out of proportion. That being said, big wheels do provide improved performance. I think that 17 inches is about as big as one can go on a small car without it looking out of proportion, but that is just my preference. Fender size and shape also matter. In my opinion, the shorter the wheelbase and/or the further the wheels are from the corners of a car the more out of place large wheels look.

Many race cars in the 70's had 13" and 14" wheels. No trouble getting decent brakes. As wheel/ tire size increases, so does mass. And unsprung, rotating mass contributes much more significantly to the effective "weight" of the car for stopping. Adding 10 pounds per tire/wheel is the equivalent of adding ~150 pounds to the car body, in terms of stopping the car.

You don't see too many Chump/ LeMons cars out there wearing rubber-band tires. 45 seems to be about the bottom end for aspect ratio there, with most in the 50-60 range, although as we've seen already the aspect ratio isn't the be-all end-all for a tire having a short sidewall. Aspect ratio being dependent upon section width, of course.

Technology has improved many things in automobiles, but probably the biggest two improvements over the past 40 years have been in the fields of a) lubrication, and b) tires. Slap a modern set of 165SR15's (if you can find them grin) and compare them to a set of 165SR15's from the 1960's and the difference will be probably more than "upgrading" the car to larger tires.

I noticed no one so far has debated the assertion that tires with larger sidewalls are easier to drive and more predictable a the limits.

Well, if the difference in traction between 0 slip angle and too much slip angle is smaller because the traction at 0 slip angle was not much to begin with, than i suppose that makes losing control a lot less dramatic.

I'll say this: vehicle dynamicists HATE the trend to larger wheels. It's largely style that drives the current trends, you just have to peek through the standard 18's and 19's to see that it's rarely driven by brake size.

Vigo wrote: Also, i have never had a car with 13" wheels that had good brakes, ever. Sure, ALL of them had brakes that were good enough that normal people wouldnt notice the difference, but none of them had brakes an enthusiast would like. Even my insight which came with 14" wheels (not sure if 13s would clear the brakes or not but i suspect yes) probably could not make one 100-0 panic stop without me having to buy another set of rotors. I admit that that is outside the envelope of normal use, but it's one reason why i cheer the continual upsizing of brakes.

F1 Cars use 13" wheels and seem to have great brakes.

With proper pads/fluid/bleeding and/or a properly designed system, its easy to have brakes an enthusiast would love that fit under a 13" wheel (provided you don't have tons of HP and or Grip). Up-sizing makes everything more expensive and heavier. Plenty of LeChump cars have brakes that would probably fit under 13" wheels (14" for sure) and they stand up to endurance racing that pushes them well beyond the levels of an average enthusiast.

I'm not a huge fan of upsized brakes on cars that don't need them.

All you need to see to become a believer in skinny tires and tall sidewalls:

my 1963 IH has factory 20's on it, all of your arguements are invalid

ProDarwin wrote:

Vigo wrote: Also, i have never had a car with 13" wheels that had good brakes, ever. Sure, ALL of them had brakes that were good enough that normal people wouldnt notice the difference, but none of them had brakes an enthusiast would like. Even my insight which came with 14" wheels (not sure if 13s would clear the brakes or not but i suspect yes) probably could not make one 100-0 panic stop without me having to buy another set of rotors. I admit that that is outside the envelope of normal use, but it's one reason why i cheer the continual upsizing of brakes.

F1 Cars use 13" wheels and seem to have great brakes. With proper pads/fluid/bleeding and/or a properly designed system, its easy to have brakes an enthusiast would love that fit under a 13" wheel (provided you don't have tons of HP and or Grip). Up-sizing makes everything more expensive and heavier. Plenty of LeChump cars have brakes that would probably fit under 13" wheels (14" for sure) and they stand up to endurance racing that pushes them well beyond the levels of an average enthusiast. I'm not a huge fan of upsized brakes on cars that don't need them.

Yes.

Comparing carbon/carbon, ducted brakes on a race car with a pair of calipers that could buy a nice new car...........yes, that is a fair comparison.

I will say this, I have enough braking force with my stock rotors and stick master cylinder and stock calipers with Performance Friction pads to not only stop my FSP Neon in a hurry, but a few years ago at an NEPA event, I snapped the braking surface of the rotor from the center hat section. Bigger brakes would do me no good and would not fit under my 14 inch Diamond wheels.

In reply to Moparman:

Big brakes often have less to do with raw stopping power than with brake fade over hard use during a long track session.

F1 Cars use 13" wheels and seem to have great brakes.

Comparing carbon/carbon, ducted brakes on a race car with a pair of calipers that could buy a nice new car...........yes, that is a fair comparison.

Glad im not the only person who noticed that.

Big brakes often have less to do with raw stopping power than with brake fade over hard use during a long track session.

Or coming down from a high speed even one time! Which is why i said ive never had a car with 13" wheels that had good brakes. Any brake an oem puts on a car and sells will stop that car in some reasonable distance, from a reasonable speed. But that does not make them any good by enthusiast standards.

As for neons, 13" wheels wont fit over my factory neon brakes. Im actually swapping them out with an older k-car spindle/brake setup that has a slightly smaller diameter rotor, GASP! But it's much thicker and i suspect the pad swept area is larger as well.

Vigo wrote:

F1 Cars use 13" wheels and seem to have great brakes.

Comparing carbon/carbon, ducted brakes on a race car with a pair of calipers that could buy a nice new car...........yes, that is a fair comparison.

Glad im not the only person who noticed that.

Yeah. That was sarcasm... doesn't always translate well across the internet.

My point about the LeChump cars stands though.

Vigo wrote: Also, i have never had a car with 13" wheels that had good brakes, ever. Sure, ALL of them had brakes that were good enough that normal people wouldnt notice the difference, but none of them had brakes an enthusiast would like. Even my insight which came with 14" wheels (not sure if 13s would clear the brakes or not but i suspect yes) probably could not make one 100-0 panic stop without me having to buy another set of rotors. I admit that that is outside the envelope of normal use, but it's one reason why i cheer the continual upsizing of brakes. One wonders: if germany did not have the autobahn, would german cars have the reputation they have today? I doubt it. But maybe we would have more 13" wheels!! Fair trade?

Really? I've had a Civic with 13, an Accord with 13s and an early RWD Corolla. I beat the living crap out of each and never had brake fade problems.

Is this a K-car thing?

Slightly off topic, but I had a rare sighting today on my way into work. Civicus Stockrimicus! A DX rocking 13's with a set of brand new Tiger Paws!