Around the Rim (Part 2)

Today's post continues the saga of rotating the rims around the various cars in the yard so we can get rid of the donor ZX we picked up a few weeks ago. This time, I focused on the spacer to get the replacement rims for the MGB (from a mid 90's Honda Accord) to fit.

Space Case

1" spacer added

ET and backspace are kind of confusing topics. To really get it, you first need to imagine the rim and consider that the spot where the rim bolts to the hub is almost never at the centerpoint between the outer and inner edges of the rim. The ET (Einpress Tiefe) is the distance in mm between that centerpoint and the spot where it actually bolts to the hub. This measurement is interesting and important when calculating how well different rims will fit. It gets more complicated as you change the wheel width. I have spent lots of time trying to figure this out (see Wheels, Studs, Chrome and Backspace), deciphering the RAtwell page on tires, and finally building a spreadsheet to help me compare rims and tires. If you have the measurements for your wheel arches, and suspension, you can jump straight into the 1010Tires offset calculator. I've played with that thing quite a bit while trying to figure out what rims I could fit on the old bus. Of course, I didn't discover it until after I'd spent hours building and refining a spreadsheet calculator. Ha! And after all that, I just bought a set of 16" rims from a guy who had them on a Vanagon (See New Shoes), so I didn't have to test my spreadsheet or other measurements in the end.

rear view w/spacer

Anyway, I believe that the ET for the crummy chromes is lower (moving the rim further out) than the stock MGB rim and much lower than the Honda Accord rim. Or the other way: the Honda ET is higher than the MGB rim which is higher than the ZX. Even if we factor in that the Honda rim is an inch wider, the offset/ET is actually a bigger factor in the math, based on the pictures.

I didn't take pictures showing how close to the wheel arch the crummy chrome rims are, but the rubber on the wheel just barely extends out past the outer edge of the arch. In the photo in my last post, you can just make out the front tire and see how it is pretty far out towards the wheel arch. Technically, this isn't legal, but with the way big trucks are allowed to drive around with tires multiple inches out past the wheel arch, I guess the traffic cops have bigger issues to handle. I can support that.

The Honda Accord rims, on the other hand, are pretty recessed into the well when compared to the old crummys. I have at least an inch of space before I'm getting near the wheel arch, and as you could see from the picture on my last post, I couldn't even get my index finger between the rubber and the spring.

Math? Why Math?

spacer on, better fills wheel well

So, after all that figuring, thinking and prior planning I'd done before, you'd think I would use the same cautious approach to solving this need. Nope. Instead, I hit the eBarf and found a set of 1-inch thick aluminum integrated-lug wheel spacers for $85US delivered. My logic:
1) I need a good inch between the rubber and the spring.
2) I have at least an inch between the rubber and the wheel arch.
3) There is nothing in the front suspension, hub nor wheel arch that is more restrictive than the rear spring to rear wheel arch.
So, if I can get a rim into the rear wheel well with one of these spacers and it doesn't rub (and it shouldn't), then we can get all 4 mounted without issue. As you can see from the top picture, there's much more room for the tire on the inside and from the middle picture, it doesn't protrude out past the wheel arch on the outside. Barely. They look right on the car now.

Now that I have proven that they can fit, and look nice in their native state, I'll be spending the next wheel-related post walking through my steps and experiments to clean them up. That's it for today. Its a little short since it's my birthday. Have a great week and as always, thanks for following along-

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.

Offset
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-

Wheels, Studs, Chrome and Backspace

Today's post is about wheels, rims and going larger-than-stock. There are so many opinions on this topic, that finding the gems of key information in the sea of religious wars is really hard. Case-in-point, there are literally thousands of threads each dating back years, covering hundreds of pages on TheSamba. Seriously, try a search for "tire" in the Samba search engine. Ridiculous. Trying to find actionable intel is virtually impossible, but, frustratingly, it is in there. There are some great sites, though, and Google can help. I'm putting everything I figure out here so I can find it again later.

RAtwell
I've mentioned Richard Atwell before. He's like the new Bob Hoover for bay window buses. I've never met him, but we've emailed over the years. His site (www.ratwell.com) has a section on tires, and it, like the rest of his site, is much more geared towards those who wish to keep their bus as stock as possible. There is a short section about going larger than stock, and the show-your-work math helped me build a spreadsheet to figure out what rims would work. If I can figure out how, I'll upload that spreadsheet so you can leverage it too. If I don't, this is a neat calculator I stumbled upon after I'd already created the spreadsheet.

Chromed

Anyway, with the info from RAtwell in my head, I found a set of Mercedes 15" aluminum 5x112 rims with flaking chrome. Yucky looking but the $50 price was right for perfectly round, undamaged rims. I started my usual way: learn how to remove the chrome first, then see if it makes more sense to pay someone else to do it. Well, with muriatic acid, it is possible to remove the chrome at home. This is strongly discouraged. No matter how many sites say that it is easy and you can handle muriatic acid safely with the right gloves, etc, the resulting chemical (Cr-6) after the stripping is highly toxic. Think "your own personal super-fund site" or Erin Brockovich. There is a reason why chroming companies are disappearing across the US. The waste produced is some of the nastiest stuff around. In short: don't do this.

So, if I can't do it, I can pay someone else to do it, right? Yes. In Portland Oregon, August 2015 it will cost $100 per wheel for an environmentally responsible shop to do it and it will take up to 6 weeks to get them back. So, my $50 rims just became $450 rims. Hmm.. Maybe I can simply scuff them up a bunch with sandpaper and paint them?

That's what she said
With the reality of stripping the chrome still stinging, I thought I'd test fit these things while I thought about it. The memory of the failed jacks (see Santa Clara by way of Wheeler) still in my mind, I slid a 2-ton floor jack under the shock absorber mount and pulled the driver-side front wheel. The kinda grody 15" rim's holes aligned, but the rim couldn't slide home. This brought up my first new discovery: many MB rims, like the ones I got, have 12mm bolt holes, some have 14mm holes. VW buses need 14mm, so the stud is too thick for the hole. This can be resolved with a 9/16" or (better yet) 37/64" 19/32" drill bit, shaving that little bit of material out of the hole so the stud's fit.

Yes, Size Matters
I also noted that the thickness of the rim at the bolt-hole is much thicker than the old steelies. Yeah, that's obvious, but its about 20mm thick. The existing studs aren't long enough to stick out the other end with enough threading for the wheels to be safely held onto the hub by lug nuts. These studs aren't very expensive, and many people claim swapping out the studs isn't that hard.

used without an "ok"
from AirCooled.net

For posterity, I derived these numbers from GermanSupply.com. The bay-window bus studs are all press-in, after 1970:
Rear (drum brakes): 37mm long, 14mm thick
Front (disc brakes): 44mm long, 14mm thick

If I were to replace the studs with a set that would fit, I would need 57mm rears and 64mm fronts (stock plus 20mm) plus or minus. AirCooled.net has studs available which are close, and after conferring with John, the 2.2" (55.9mm) should work on the rear and 2.5" (63.5mm) should work on the front. I know my history enough to know that it could take me a day per wheel (I'm slow. I make mistakes and I don't like doing too much at once). Once I run that math, I expect mounting these $50 rims to cost me thousands in my usual charge-myself-$50/hour planning. Before I take that plunge, I switched my focus to thinking about simply buying rims from Cip1 or jbugs.

Rub Rub Rub

nicked from JBugs

There are all kinds of really nice looking, shiny rims on the market. They so pretty. Unfortunately, the new rims out there are not designed for the rear fenders of the bay window bus. Those rear "flares" don't flare out very far, and most of the rubber above the top of the rim is covered by it. This limits the ET the bus could support.(from RAtwell's tire section: ET is German for Einpress Tiefe. and it's the measurement in mm from the rim center line to the mount where the brake drum or hub contacts).

The websites don't publish the ET of these new rims. They talk in terms of inches of backspace. Backspace is the distance from the inner lip of the rim to the wheel mounting face. Since we know the backspace and the ET for the stock wheel, we can figure out the ET, though. Ha! The stock rim has a backspace of 4.75 inches and an ET of 39mm. Most of the new ones have a backspace of 3.75 or 3.5 inches. These lower numbers push the wheel further out from the hub, lowering the ET. If you've ever tried to put tire chains on the stock rear tires, you know there simply isn't that much room. Once we add in the section width, pretty much any tire that isn't one of those extreme low profile (requires special tire-mounting equipment) tires won't fit. Still, let's do the math: 1 inch equals 25.4mm, so shifting the ET of 39mm down by an inch puts it around 14 (39-25=14). I ran another math model where it was closer to 20, but the point is the same: the new rims are designed for a Vanagon at best, but more likely a beetle or squareback. Some metal work, either to the rims or your rear flares, will be required to make them fit.

Hope Glimmers?
There's one last glimmer of hope for a relatively quick swap rim: the newer Passat rim. The newer Passat, and some Audi's, were shipped with a 15" steel wheel on the 5x112 base. Unfortunately, the center hole for these rims are closer to 1.5" than the required 2.5" needed to clear the grease caps and castle nut on the old bus. I happen to have a set of these 15" rims. Of course I do. You knew I would. I've read about expanding the center hole, but tire shops won't do it out of fear of getting sued. Gotta love the American system sometimes. Anyway, it is entirely possible to figure out the right line to cut and then cut it with a special drill bit, or a Dremel. Frankly, that sounds like a bad home-mechanic idea. The probability of making the rim unusable is pretty high. And, while the tire shops fear lawsuits, they fear someone getting hurt or killed because of one of their rims failing even more. That fear is contagious; now I fear that too. I suppose, if I knew a tire guy who could assure me that it could be done right, maybe my fear could be eased. Until then, that set of rims will sit, and eventually fall onto craigslist for someone to use for snow tires.

So...
I'm back to the original grody-looking rims. I picked up a 9/16 drill bit last night, and tonight I'm going to have a go at one of the rims.

UPDATE (August 24th, 2015): 9/16 is too small. While it did shave some material away, 9/16" is 14.29 mm and the threads are bigger than .29 mm. I have since ordered a 37/64" (14.68 mm) and a 19/32" (15.08 mm) bits. I'll update once I've determined which one worked best, removing the least material.

test fit success

UPDATE (August 29th, 2015): 19/32" is right. 37/64" didn't make a large enough hole for the rim to fit. 19/32 made it fit without wrestling, and the rim isn't flopping about sitting on the studs. As you can see from the picture, the 15x6 MB rim should look pretty good, once that chrome is covered up. Next, I'll have to get after the studs, etc. I'll post about that separately, when I get to it.

Thanks for following along... if you did. There's many hours of research distilled down into about 1400 or so words.