Tuesday, February 13, 2018

Around the Rim (Part 1)

Today's post looks at rotating tires, one set at a time and some planning / thinking around how to rotate tires from car to car, ending up in a better place than where we started when the music stops. This got really long, so I'm splitting it up into sections (again). Today, we'll focus on how this rim job got started.

The Catalyst
rusty rim
A couple months back, I pulled out the studded snow tires and my floor jack, to get Flash the Jetta ready to be our snow tank when winter turned nasty. While I swapped my 3-season tires for my studded snows, I got thinking about how we were going to finish the stripping work on the donor, and then getting the remaining shell removed. "If we pull the wheels, how will they get it out of here," I asked myself. By the time I'd gotten the winter tires on the Jetta, and the 3-season tires stored, I thought I had a plan.

My Logic
When we got the part-donor 280ZX, it was originally because C wanted the rims. I did a little research and found that most of the time when you have a yard pick up a scrap car, they give you less money if the car doesn't have wheels. I guess this is because they can't use their usual tricks to get the car, and someone has to pay for the nuisance. That someone is you. The interweb says that there are some yards that simply won't accept a junk car without wheels. I'm not fully sure that's true because sometimes the Interweb is wrong, but with that thought, I started thinking about how we could resolve a potential rim shortage.

The 280ZX and the MGB run the same size rim: 4 holes by 4.5 inches (or 114.3mm) apart. The backspace / ET is different, but they are close enough that they mostly fit each other. In fact, I'm fairly sure the rims currently on the MGB are 280Z aftermarket rims. But they're crummy fake wire-spoke rims that has the chrome flaking off, leaving large rust swathes around the lugs (see picure above). They're awful, and within a few days of getting the MGB I decided I wanted to replace them. To avoid possible junk-yard-wont-take-it issues, we're going to put them on the donor ZX. With that settled, the MGB will need rims before the donor shell gets removed. Well, the rims on the keeper 280ZX would fit, but as I described in the post about how we got the donor car (See 280ZX*2=Y), they just aren't our style. We are going to keep the smaller front rim/tires as a spare for each of our cars (one each 280ZX, MGB). This leaves us short one set after we move the donor ZX rims onto the keeper 280ZX and the crummy chromies from the MGB to the donor.

The Rims
Honda rim
I hadn't intended to keep those crummy chromy rims in the MGB anyway. I'd been looking, but original-looking aftermarket rims are, like $175US each. I'd been leaning towards getting a set from Acme Speed Shop, but I needed to corral $800US to make that happen. Knowing that simply wasn't going to happen soon, and having rims would enable us to ship the donor to the wrecker.... I went a different way. I had been trolling craigslist like I do when I stumbled upon a set of alloys that used to ride on the mid-90's Honda Accord. They looked okay in the posting, and the seller assured me they held air, so I took off to nab them. $100 later, I have a set of rims (with trash rubber) I can put on the MGB. I didn't go into this blindly. There is a great resource on the MG Experience identifying rims that fit. I figured with a savings of nearly $700US, I could clean up the Honda set, maybe apply some paint and still be ahead cost-wise. Or, I could just clean them up and sell them to fund one of those Acme sets.

Test Fit First
This sounds obvious, but so often we'll get all excited about something and tear right into the doing without first checking to see if what we're about to do makes any sense. Case-in-point, I could have started repairing on the curb-rash before even checking that the rims even fit. Again, the Interweb sometimes is just wrong. Okay, maybe I did get excited a little. But, it was no more than a few minutes of cleaning before I realized that I hadn't verified the linked resource. So, I pulled off the rear passenger (right) side wheel and slapped on one of the new-to-me Honda rims. The bolt-pattern was a perfect fit, so with very little wrestling the rim was on, nutted down and on the ground. So far so good in terms of the linked resource.

crummy chrome backspace
I took one of the other new-to-me Honda rims and set it next to and then on top of the crummy chromy rim I'd removed. The rubber (tire width) is about an inch thicker with the new rim, which aligns with what I was expecting. The new rim is 15" diameter and 6" thick. The one I removed was 14" diameter and 5" thick. The thicker rim supports a wider tire, so checking clearance both at the leaf spring and at the wheel arch is important.

As you can see from the pictures, the crummy chrome rims sat much further out towards the wheel arch than these Honda rims. There is almost 3" between the leaf spring and the tire sidewall. In contrast, the Honda rims sit quite close to the leaf springs, so close I can't even fit my index finger in-between the spring and the tire (see the lower picture). This leads me to believe that I am going to need spacers to center the rim between the leaf spring and the wheel arch. Spacers aren't nearly as expensive as I'd feared, running $10US per corner for off-the-shelf spacers. I just need to determine how much space I need and then figure out what lug nuts I need to make sure there's enough thread to hold the rims on well. To clarify... consider that the lug bolt (stud) is a fixed length and the more space you put between the hub and the backside of your rim, you are potentially taking away threads. The holes in the spacers for the lug studs are usually loose enough for you to get extension nuts that will thread between the spacer and the stud so you can still use most of the stud threading to hold on your rim. This takes care. If the extension on the nut is too long, you will bottom-out before the nut can be torqued on. If you use a nut that has too little (or no) extension, there may not be enough thread to safely hold your rim on.

Honda backspace
Or, there are slightly more expensive spacers which have lug studs integrated into them. T got a set of these when he was going to fit old (80's) Mercedes rims onto his not-quite-as-old (90's) Subaru. In fact, I used one of them to make the camping table attach to my spare on the bus (See Camping Table) after he got rid of that old Subbie. This style also lets you change the bolt pattern, if you want. You could run 5-lug rims on a 4-lug car without a whole lot of work. The upside for my application is that the spacer is nutted down onto the hub and the rim is then nutted down onto the spacer. This leaves plenty of meat on the respective lug studs to make sure your wheels are on safely. I have found 4-wheel sets delivered for under $100US, so while it's more than double the slide-on style I described first, if you add in the expense of getting the right lug nuts to be safe, the prices could nearly wash-out. Plus the added headache of time lost getting one set only to need something different, etc. Of course, the sense of security that comes from knowing that your wheel isn't going to fall off makes the decision much easier. I just need to figure out the right amount of backspace. I'll address that next.

That's it for today. Thanks, as always, for following along-

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