Wheels and Tires...compiling a list...ever so slowly

[vwthingboy]

So, has anybody put together a list of issues related to changing wheels and tires?
Below is an initial cut at it, to be updated with input from the gallery...i.e. your expertise. (Items with "?" are in question)

Ideally we could put a list together of all wheels that will fit a stock setup and go from there.
Potentially, we could have a gallery of different wheels, listing any mods that have to be made in order to use them.

If I understand properly, the concerns are:

Wheel diameter: 14" vs. 15" or larger (some disk brake setups require 15" wheels due to large diameter brake rotor).

1973 and 1974 Mexican-built for the U.S Things came stock with 14" Thing-specific wheels, but 15" were available as an option. As early models were never mass imported to the U.S., the 15" rims are very rare. (from VeeWiki)
From TheThing.org: http://www.thething.org/frame37.html

From 1 March 1973 onwards VW 181s had unique 5JK x 14" wheels fitted with 185 R14 tyres. These VW 181-only (they have a 181- part number) are different from other 5JK x 14" VW wheels in two major respects:
1. The off-set dimension is greater than the other 14" wheels such as those used on the type 2. Use bus wheels on your VW 181 and everything will scrape a bunch.
2. The original VW 181 wheels are un-slotted, solid centred. All other 14" VW wheels are slotted.
From Hanno's site: http://www.geocities.com/vwtyp181/index.htm

Wheel width: Stock 14" wheels were 5" wide
Optional 15" wheels were 5.5"? wide (and can safely hold up to a 235mm? wide tire).
Aftermarket wheels range from 3.5" to 10" wide or more.
The issue with wide wheels and tires is rubbing on the front suspension, how the load is placed on the hub or lugnuts, and fender coverage.

Max tire size = ??
Tire Width: The original stock tire size was 185SR14. Both Continental and Goodyear were OEM suppliers.
1968-1972 German models had 165/15 tires on 4.5 x 15" rims; later models had 185/14 tires on 5 x 14" rims as original equipment.
It is commonly said that the widest tire that will fit on the front of a Thing with stock wheels, fenders, and ride height is a 205mm/75mm/15".
Additionally, a 185mm-width tire is about all that will fit under the hood as a spare.
The variables of tire size, wheel diameter, wheel offset, and front end ride height, all effect the maximum tire size without rubbing.

Stock lug diameter or "bolt pattern" or "bolt circle" is 5 x 205mm (or 8.07") also known as "Wide 5"
http://www.tirerack.com/wheels/tech/techpage.jsp?techid=92
(The lug configuration can change with the use of different brakes or wheel adapters)
Wheel adapters change the lug pattern and add "unsprung" weight to the wheel/tire combo. Some people feel they are unsafe.

"Offset" which is the distance from the wheel's inner hub mounting surface to the centerline of the wheel.
http://www.tirerack.com/wheels/tech/techpage.jsp?techid=101
(Stock Thing offset is ?? positive)
If the offset of the wheel is not correct for the car, the handling can be adversely affected. When the width of the wheel changes, the offset also changes numerically. (From Tire rack)
Offset that is not correct can improperly distribute the car's load.
Wheel spacers change the offset, may require longer lugnuts and add "unsprung" weight. Some feel they are unsafe.

"Backspacing" is measured by laying the wheel face down and laying a straight edge across the diameter of the wheel then measuring to the wheel's hub mounting surface. The distance between the straight edge and the inner hub mounting surface is called "backspacing" or "backspace." That's where the measurements such as 4 .25 backspacing etc come from.

Old VW wheels can be difficult for tire shops to balance as the shops don't have an adapter to fit the wheels.
(If you have an old brake drum you can bring it with you to use for balancing?)
Old VW wheels are "Lugcentric":
http://www.tirerack.com/wheels/tech/techpage.jsp?techid=91
The big hole in the center of the wheel gives the tire shops fits.
Improperly balanced wheels can create the "wobbling" phenomenon which creates shaking in the steering components and vibrates the steering wheel at around 50-55mph.

Lug seats of different wheels: the shape of the metal where the lug contacts the wheel
http://www.tirerack.com/wheels/tech/techpage.jsp?techid=102

Stock lug nuts are 12mm? long
Wheel studs can be installed in brake drums or rotors. The wheel is held in place with wheel nuts that fit the studs.

Valve stems. Metal versus rubber?

Tire inflation levels. Stock PSI settings (19lbs in front) were based on old tire specifications, and may not apply to, and be too low for, modern tires. Or maybe the front tire pressure is spec'd so low because the weight of the Thing's front end is relatively low. This is a point of some (mild) controversy.
In general, a higher tire pressure improves steering response and handling, but also increases ride stiffness.
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=1

Overall tire diameter should be selected based on type of engine and transmission used. A motor with more torque will offset the greater tire diameter just as well as lower gearing.
Some people use tires that are too large for the Thing's transmission. Offroad applications may use lower-geared transmissions.
In general, smaller tires have less rolling resistance and improve gas mileage.
Also, larger tires will effect the mph number shown on your speedometer.
If you are using larger tires, the number on the speedometer is lower than your actual speed. (Are there different speedo cables that account for this?)

Additional modifications that effect wheel and tire selection/applicability:
Front:
Different front beam (narrowed or widened)
http://www.thething.org/frame26.html
Beam adjusters which can raise and lower the front beam
Spindles different than stock - people switch out to lower the car
Rear:
Rear suspension modifications -
Adjusting the "splines" refers to the rear torsion bars and adjusting how the torsion bar plate attaches to them. Normally this method is used to raise the rear, for offroad applications or to correct the rear "sag" that occurs over time.
3" wider and 3" longer trailing arms are used on some offroad setups. Suspension mods can add "travel" to the system, which allows it to travel more vertically, up and down.

Ideally there could be a table correlating the variables of tire size, wheel diameter, wheel offset, and front end ride height, all of which effect the maximum tire size without rubbing.

I've probably left out a bunch of stuff.
Feel free to correct or add info.

-Sean in NYC

[Captain Spalding]

I love the idea of a single thread that answers all these wheel related questions. Perhaps once this thread has run its course, you could distill all the info into a single post, and ask that it be made into a sticky.

[LEJ]

[vwthingboy]

Mental exercise du jour:
The largest tire that will fit under a Thing is 205/75/15.
That tire should be 27" tall and 8" wide, so those would be your max dimensions.
(Math: 205mm/25.4=8.07"...8.07x.75=6.05...6.05x2=12.1"...12.1"+15"=27")

In theory, then, wouldn't a 205/60/17 tire be the same size overall?
That tire should be 26.7" tall and also 8" wide.

So, as long as the offset is correct, a 17" wheel could fit, no?
Or an 18", 19" or 20" wheel with lower profile tires, as long as you don't exceed the 27" by 8" limits.
And doesn't it also mean that you could use any wheel width, up to as large as 8" in the front without narrowing the beam or getting wider fenders?
(That French Thing in the classifieds, which may never sell, got me thinking)

[Captain Spalding]

Don't run out and buy those tall rims yet . . .

Theoretically speaking what you are saying is correct. You can relax and forgo the mental exercise by using this nifty Tire Size Calculator. I compared three different sizes, and here are the results:

But theory and practice are often at odds, and such is the case in this situation. I sidled over to TireRack.com and did a search for 205/75R15. There were 31 tires available in that size. I also did a search for 205/60R17 and 205/55R18. There were ZERO results. That doesn't mean that tires in those sizes aren't available anywhere, but certainly your choices will be limited. Compromise will likely be required.

[scamutz]

While we're on Tires/Wheels...does anyone know of a supplier that is familiar with Thing wheels and the offsets?

I'd like to order some new wheels..Radars, or something similar. but don't want to go through the headache of having to explain the offset etc.

Anyone?

TIA

Mike in Tampa
'74 Thing - "Verna"

[scamutz]

http://www2.cip1.com/SearchResults.asp?Cat=1932

For instance....would these fit? They are apparently all 5x205mm

TIA

Mike in Tampa
'74 Thing - "Verna"

[fisheye]

I just purchased some wheels from CIP. I have not mounted them yet though. The backspacing is the key item you need to look at. I have 15x6 wheels with only 2.5 inches of backspace right now and they rub in the front. I just bought the 15x6.5 BRMs with 4.125 inches of backspace. This should move the outer edge of my tires in by nearly 1.5 inches (in theory). I will post the results when I get the tires mounted.

[Stevec6x6]

this thread rocks..

sticky this bad boy.

[Ian Epperson]

[Towel Rail]

With Things, I think tire width becomes a problem before tire height. If you go out and peek under the fenders, there's plenty more room above, to the front of, and behind the tire. However, the tire can only get so wide before it gets close to the suspension-limiter-parts (dunno the real name) in back, and rubs against the front fenders when turning. Of course, make your front tires tall enough, and they'll rub on turns no matter how skinny.

[vwthingboy]

To me, the most confusing part of the issue is the backspace and offset.

I haven't found a definitive answer to what the stock Thing backspace and offset are.
I assume it's different for the 14" and 15" rims because they are different widths.

Those Rader rims from Cal Imports have a 3.25" backspace.
They are 5" wide rims, so the wheel centerline is at 2.5".
That must mean they have a .75" positive offset.
(Impressive math, eh?)

[fisheye]

If they are marked 3.25 in backspaced, the 5" rims the center would be 2.5 inches, however the face of the wheel that attaches to the drum will be 3.25 inches in from the outer edge of the inside lip of the wheel or 1.75 inches in from the outer edge of the wheel. How is that for a long run-on sentence?

[fisheye]

Here are my results on the 6.5 inch BRM style wheels from CIP1. I have 215x65x15's and they seem to fit in all areas except one. They rub very slightly on the end of the upper beam when the steering is turn all of the way to the right or left. The tires run - not the wheels. So far no fender rub in the front though! I may put 205's on the front to stop the rub if becomes a problem.

[emersonbiggins]

[Towel Rail]

[emersonbiggins]

Drilled drums, no adapters.

On the back I had to countersink one of the spring plate bolts and cut a little off the snubber plate.

On front, I didn't have to change anything. Not even the stops for the steering box.

I am installing front discs now with beetle spindles.

[Towel Rail]

[emersonbiggins]

[scamutz]