32 replies to this topic

[Steve Okeefe]

 

 

 

[Martin]

Most of the cars I restore have a maximum width at the tires of 3'' and that is well documented here with the 1970 NCC rules.

 

So now I am restoring some mid to late 70s cars maybe even 80s. My question is when did the rules change to 3.25" at the rear tires.

Is there any rules written that would date this change?

Thanks for any info on this.

[Bill from NH]

In USRA-East, we went from 3" to 3 1/16" during the mid-70s. I don't know when it expanded to 3.25". I recall the 3 1/16" width because I widened one of the red Champion Check-Tech tools.

 

I checked on a couple items, my modified Check-Tech tool is 3 1/8", rather than 3 1/16" as I thought. My first USRA-East membership card was issued in 1975, so they had no impact on the increased width as I had thought. I took 1976 & 77 off from racing after having raced several years at the increased width. In '78 I moved to NH.

[Pablo]

Steve's timeline indicates the change from 3" to 3 1/8 was 1972. Timeline ends in 1973 still at 3 1/8.

 

I know that doesn't answer your question. Maybe Swiss or Hershman would know.

[Martin]

This is great info guys, thanks.

I though there might be a progressive shift. 3" to 3 1/8" then at some point it went to 3 1/4" till today.

 

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[Martin]

I found this Arco Tek Chek tool in a slot box from the mid to late 70s.

It has a 3'' space and a 3 1/4'' (3 .240") space. Nothing in between. Also the wheels spaces are 3/4"X3/16 for front and 7/8" X 11/16" for rear.

Interestingly it is made from .058" material. For 1/16'' ground clearance I presume with a bit of leeway ?

In this tool all the space's are a few thou undersized except the 3'' .

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[88honcho]

Dad (Gator Bob) built this tribute Group 12 car to the above rules.

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[Martin]

Nice car Nicholas, but the answer I am looking for is when the rules changed from 3" to 3 -1/16" to "3 -1/4" on the outside of rear wheels.

Maybe there is not one answer.

Bill, was there, so thank-you for this "In USRA-East, we went from 3" to 3 1/16" during the mid-70s"

Would be great to see something in print. They do not call it the dark ages for nothing.

[Pablo]

Here is an idea: send a PM to PdL in his trailer and ask him. He was there.

Or a PM to Steve Okeefe. If those two guys can't nail it down, nobody can

[Martin]

I sent a PM to Steve a couple of days ago, but he has not read the message yet.

Then I ask Frank a friend who owned Slot car raceway and he called PdL (I did not realize he had his number) Frank said PdL said it changed 3" to 3 1/4" at the wheels in USRA rules in1969.

So I am not sure if the question was worded correctly or if PdL was saying the overall width of the cars was 3 1/4" so I am still in the dark.

 

[Phil Smith]

PM Philippe.

[Martin]

thanks, waiting for a reply now.

[Bill from NH]

Ken Stevens in Houston might know also. He was my racing buddy in the '70s at Modelville Hobby & C&C..

 

I'd wait for Steve to get back to me.

[Martin]

Thanks Bill, I am starting to believe that the rule change is lost to the "Dark ages" of time.

All the people I have spoken to, dropped out early 70s only to return when the 3 1/4" was already in place.

 

As a side related question, when were tracks made with 4 1/2" lane spacing. It was always 4" when we had 3" wide (at the rear wheels) cars.

[MSwiss]

Tracks went to wider lane spacing when Sweden's Hasse Nilison started building King tracks, in either the late 70's or early 80"s.

 

The wider King tracks from Hasse and Steve Ogilvie started at 4 1/4" or 4 3/8".

 

4 1/2" lane spacing probably didn't start until the 90's , IIRC, with Chris Dadds.

 

We even ran on a Hillclimb/Grandstand style track, with 4 5/8".

[Bill from NH]

That;s a good second question Martin but I'm, not going to be of any help. The tracks I ran on in the late '60s into the '80s were a variety of old tracks. The first new tracks I recall running on were Steve Ogilvie tracks in 1996. When on the old tracks, I paid little attention to lane spacing.

[TSR]

The NCC rules are clear: max 3" width outside to outside of the wheels (FR and RR), with the front axle (which at the time was alwaus solid) able to slide 1/8" out on each side.
Maximum BODY/CHASSIS width taken outside of the body including mounting tape and pins: 3-1/4".

The 3-1/4" width never changed as far as I know, but the wheel width dimension from outside to outside did, to 3-1/8", I only said 3-1/4" to Frank regarding the body/chassis combo, I just do not know when was the change, and it could have been different from raceway to raceway...

That's all I know or remember.

[Martin]

Thanks Philippe, I thought my question to Frank might have got mixed up. I clearly ask him about the rule change to 3/14" at the rear wheels.

 

So we know it was 3 1/8" in 1973.

My "Tek chek" tool ( post 6) is 3 1/4" and 3" I wonder if that was 3" for the out side of wheels and 3.25 for the out side of body?

[Phil Smith]

Tracks went to wider lane spacing when Sweden's Hasse Nilison started building King tracks, in either the late 70's or early 80"s.

 

The wider King tracks from Hasse and Steve Ogilvie started at 4 1/4" or 4 3/8".

 

4 1/2" lane spacing probably didn't start until the 90's , IIRC, with Chris Dadds.

 

We even ran on a Hillclimb/Grandstand style track, with 4 5/8".

 

Were there rules for the tracks?

[jimht]

The 1979 USRA Rulebook states 3 1/4" width overall with no width for the tire track.

 

Bob Rules' proposed Group 7 rules from 1973 is where I see a change from NCC 3" tread & 3 1/4" max width to 3 1/8" tread.

 

I think we ran 3 1/8" tread at my 1974/1975 Nats but I'd have to dig out some pics of the cars to verify that (unless there's something here on SlotBlog?).

 

So, 3" tread up to 1973/4. 3 1/8"up to the Bicentennial race (?), 3 1/4 tread in 1979 for sure.

[dc-65x]

Not sure if this is helpful but I found this:

 

 

[Bill from NH]

My "Tek chek" tool ( post 6) is 3 1/4" and 3" I wonder if that was 3" for the out side of wheels and 3.25 for the out side of body?

 

That's how the tool was used here in New England.  That's also the reason why I lengthened the 3" notch to 3 1/8" when the rear tire width increased,

 

If you can find somebody with copies of past USRA rules in the '80s & '90s, you might be able to determine when the 3 1/4" rear tire width was first approved.

[jimht]

Not sure if this is helpful but I found this:

Right. As Martin said earlier, it was a progressive shift.

 

I'm pretty sure the California USRA adopted 3 1/8" tread well before the TSRA did.

 

It was only when we and the East coasters agreed to use the USRA rules that they became "National", even though the East Coasters kept their "Wagon Wheels".

[Bill from NH]

The first wing car I built in 1970 had 3/4" fronts & 7/8" rears. Those might have been considered wagon wheels. The second wing car I built in 1970 & others built since, had 5/8" fronts & 13/16" rears. These were not wagon wheels at the time, though they would be considered that today. 

[Martin]

Thanks to all the folks that have given this some memory jogging we start to get a clearer time line on the shift to 3 1/4" outside of wheels.

 

This car is 3 1/8" at the rear tires. Can anybody tell from the components, wings etc. what year this would have been made.

I was always thinking it was 76 but I may be putting too much stock in the number on the car?

 

P.S. this car was raced Oakland, San Leandro area.

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