Spare and larger rotors

[pitzel]

I upgraded from the smaller rotors to the larger rotors by changing the knuckle assemblies, and the rotors themselves.  The calipers now ride very close to the edge of my 15" rims, and going to a smaller rim would permanently not be an option.

Will I have an issue installing the donut spare that the vehicle came with?  

[Amanita]

If you have the same size spare I do, then it is very likely. It wouldn't hurt to do a test fitting, but I wouldn't expect it to fit.

Edited February 26, 2020 by Amanita

[Schurkey]

On 2/26/2020 at 1:52 AM, pitzel said:

I upgraded from the smaller rotors to the larger rotors by changing the knuckle assemblies, and the rotors themselves.  The calipers now ride very close to the edge of my 15" rims, and going to a smaller rim would permanently not be an option.

Will I have an issue installing the donut spare that the vehicle came with?  

Doesn't matter.  You'd never install the "donut" spare on the front anyway.  If you blow a front tire, you put the donut on the rear, then put the rear tire/wheel on the front.

[vipmiller803]

9 hours ago, Schurkey said:

Doesn't matter.  You'd never install the "donut" spare on the front anyway.  If you blow a front tire, you put the donut on the rear, then put the rear tire/wheel on the front.

Maybe, but do you know anyone who has actually done that? I've done roadside work professionally and we never even think twice about putting a donut on any corner.

Scientifically speaking, it's actually a tough call. Lower available patch area on the front increases your braking distance significantly in dry weather. But less tire in the rear can easily cause more harm in the form of oversteer in a panic move.

Sorry. Little bit of a thread jack/tangent. To the OP: I'd test fit, and if you have clearance issues just buy a donut from a yard for the vehicle you swapped knuckles from.

[Schurkey]

2 hours ago, vipmiller803 said:

Maybe, but do you know anyone who has actually done that?

 

Me.  My wife ('cause I've shown her.  Remains to be seen what she actually would do.  Call a tow-truck so someone else gets dirty, is my guess.)

 

 

 

Given that the vehicle is equipped with a piece-of-crap spare tire, yes, it's a lesser-of-two-evils choice.  The lesser evil is to put the donut on the back, and get a real tire up front.  A FWD vehicle does ALL of the steering, ALL of the driving power, and MOST of the braking with the front wheels.  Mis-matched front tires are hard on the differential, which has to spin the side-gears to resolve the different rotating speeds of left and right wheels.  The front of the vehicle is significantly heavier than the rear.  By comparison, the rear wheels of a FWD car primarily serve to keep the rear bumper from scraping the pavement.  The shitty tire belongs on the rear; and hopefully the driver knows to not over-speed into a corner, or abuse the brake pedal in a way that causes oversteer.  The 60-mph speed limit on donut spares is not because the tire can't take higher speed.  It's to limit the likelyhood of oversteer when the tire is on the rear; or to limit the amount of understeer, and reduce overall stopping distances if the donut gets mounted on the front.

Of course, just as the owner's manual says, you get the faulty tire repaired or replaced as soon as practical, so that the crappy donut spare can be removed.

Edited February 27, 2020 by Schurkey

[pitzel]

Oh trust me, driving on the donut spare is a real treat on the passenger front position, and I had to do that one night being ~200 miles away from civilization when I had a blowout in rural western Canada.  With the donut spare not even properly aired up.  I kept it under 40mph the whole way.  And then when I got home, rotated it the rear passenger side, aired it up properly and drove another 40 miles in daylight to have a brand new set of 4 tires thrown on at Costco.

That was prior to the rotor upgrade...

If I blew out one of the fronts, I could jack up a good rear, remove it, install the spare, and then jack up the front...  Of course that'd add considerably more time to the whole operation.

Can definitely pick up a larger donut from like a 97 Lumina or something.  But just wondering if, by chance, anyone knows whether that'd be necessary or not..  I guess I'll just have to try it out..  

 

[vipmiller803]

7 hours ago, Schurkey said:

The shitty tire belongs on the rear

Again, different schools of thought apply. It's the same reason why many tire places will not put a set of two new tires on the front. Oversteer potential. We see it all the time here. It doesn't take much of a corner, just a slightly crappier set on the back with the right conditions (rain or snow) and you find yourself turned around in a hurry, especially in cars with no stability control - i.e. pretty much all W's. I'm not saying you're wrong about the donut being better for you specifically or for the car on the back, but the argument can be made the other way around. For equally sized tires, no argument can be made for putting the better ones on the front.

[pitzel]

6 minutes ago, vipmiller803 said:

Again, different schools of thought apply. It's the same reason why many tire places will not put a set of two new tires on the front. Oversteer potential. We see it all the time here. It doesn't take much of a corner, just a slightly crappier set on the back with the right conditions (rain or snow) and you find yourself turned around in a hurry, especially in cars with no stability control - i.e. pretty much all W's. I'm not saying you're wrong about the donut being better for you specifically or for the car on the back, but the argument can be made the other way around. For equally sized tires, no argument can be made for putting the better ones on the front.

Yeah for sure, the fronts in a FWD car have the benefit of the heavy engine providing force to keep the wheels on the road, and hopefully going straight.  The rear, which has relatively little weight applied, relies heavily on the tread of the tire in lieu of the weight.  

Sure, having the 'better' tires on the front might make for better starting out on ice, but that's about the only benefit, and once you're up to speed, lateral stability is far more important.

My long drive on the spare was in dry summer conditions on a divided highway at lower speeds.  If it were winter, on a single lane highway, I may very well have found the closest small town and stayed the night.  

Edited February 28, 2020 by pitzel

[Cutlass350]

Can't you just buy a spare that came with a vehicle that uses those spindles?

Like one from an Olds intrigue or Aurora?

Ebay search:
olds intrigue spare
Note: Check the donor car year/model before you buy.

$49 - From an '96 Olds Aurora
https://www.ebay.com/itm/Wheel-15x4-Compact-Spare-Fits-92-05-CENTURY-754962/193308045164


When I did the brake upgrade to my Mustang (in the mod 90s), there were very few cars even sold with 17" rims.
I had to go to a body shop, swear on my life with my hand on a classic car, that if they found a spare, I would pay "up to $xxx" and I'd pay before ordering, and with in 2 days of being told they found one.
What a PITA.
I could buy the bare rim from Ford. But, only Ford sold the tire. And, they would only replace tires on existing rims, or if someone owned and brought in a correct car, and gave them enough of a story on why they no longer had even a bashed up rim.

Iirc, it cost me $300, even way back then.
But, playing around doing a "wheel swap" is a great way to double the chance of being plowed right over by Mass and Conn drivers. And, I quickly got sick of having a full-size tire sitting in my hatch area.


Good Luck!

Edited February 28, 2020 by Cutlass350

[bluecalais79]

I sacrificed trunk space for a full size spare tire, lug wrench, scissor jack in the trunk in both my CS rides. Agreed those donuts are all but worthless but they do make a great anchor for extra weight where they are. If I get a flat I change the tire, off I go instead of limping to the next closed station, etc.

I've gone so far as to place in sound deadener clean over the entire trunk area (without using the adhesive so if I really need to get in there I can) and got one of those Lloyds carpet mats for each car to kill some noise that would otherwise go right into the cabin.

 

[Schurkey]

On 2/27/2020 at 2:11 PM, Schurkey said:

  The shitty tire belongs on the rear

Evidence:  Nine dead in Texas, because a spare tire that some moron mounted on the FRONT blew out.

https://nypost.com/2022/03/17/ntsb-child-was-driving-pickup-that-struck-van-killing-9/?utm_campaign=nypdaily&utm_source=sailthru&utm_medium=email&utm_content=20220318&lctg=607d91b1373dd11b6ec2ef72&utm_term=NYP - Morning Report

Naturally, the media is focusing on the WRONG thing. They're making a big deal over the age of the driver instead of the faulty spare that blew out causing the loss of control.  The tire was a bigger cause than the driver.  (The underage, inexperienced driver had adequate control of the vehicle UNTIL the tire popped.)

Being that this was a spare on a pickup, it may have been a full-size tire.  Point being, it wasn't taken care of, the spare was in-use for too many miles, and the kid didn't have enough experience at the wheel to control a vehicle with a flat.  But that could have been just as true for his dad.  Plenty of adults/experienced drivers lost control of Ford Exploders when the defective-junk Firestoned tires popped.

The shitty tire belongs on the rear.  The LAST place you want a shitty tire is Left Front--so when it pops, the drag from the blown tire puts you into the lane of oncoming traffic.  At least with the shitty tire on the right-front, you're more likely to hit the ditch and only kill people in your own vehicle.

Edited March 19, 2022 by Schurkey