# Axle and Wheel Measurements



## Grandcheapskate (Jan 5, 2006)

I have been measuring the various axle, wheels and armature shafts of selected Aurora, Tyco (440 and HP-7), Tomy (Turbo, SRT and SG+) and Lifelike (M&T) chassis. I have been putting them into a spreadsheet.
If anyone has done this before I would like to compare the measurements I took with those you may have taken.

Just send me a PM offline.

Thanks...Joe


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## yellerstang (Feb 20, 2012)

Please post this info when you get it done! Thanks


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## Frank Broughton (Jan 31, 2016)

Yes, please do post it!


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## Grandcheapskate (Jan 5, 2006)

I can see why no one has done this before. The axle sizes are pretty standard but the wheels sizes, even on the same type chassis, can vary by a hundredth or more.

I am pretty much done with taking most of the readings but sure would like to compare my measurements with others.

Joe


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## Rich Dumas (Sep 3, 2008)

Many of the stock wheels that I have measured actually have a slight taper, the diameter is greater near the inside. Even some CNC wheels have a taper, that happens because the plastic flexes more where the wheel is dished. Some makers compensate for that effect, others do not.


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## Grandcheapskate (Jan 5, 2006)

An interesting point on tapering. That may account for a few thousands, but the differences I am seeing appear to be larger than would be explained by a slight taper.

As an example, I measured the O.D. on a few rear wheels on Lifelike M cars. I got a low of .277" and a high of .288". So when buying tires for Lifelike M stock wheels, I guess you would have to assume the smallest O.D. (at most .275") to be sure the tires are snug enough so they won't slip off.

Joe


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## tabcomary (Jun 2, 2010)

*Taper*

The Aurora A/FX rear wheel samples I am looking at might only taper a thousandth or two from inside to outside, if they taper at all. That small a difference can easily get swallowed up in imperfections in the casting. The small imperfections were all covered-up by the foam tires anyway.

Aurora Specialty Chassis "narrow" rims appear to taper from 0.375" to 0.372" pretty consistently.

Aurora Specialty Chassis "wide" rims appear to taper from 0.380" to 0.372".

I also have some AW 4-Gear rims that appear to get larger from inside to outside (0.378" to 0.382") That might be a result of the thick coat of silver paint that appears to much heavier near the outside of the rim. 

I expect that the un-coated AW rims have a taper similar to the Specialty Chassis rims. That is just one of the things you have to do when you mold plastic.


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## Rich Dumas (Sep 3, 2008)

I expect that injected plastic shrinks a little when it cools. If you are trying to make parts to specific dimentions you would have to take that into account when you design moulds. 
I know that in the case of Super Tires they are designed to fit specific wheels. The ID of the tire is slightly less than the OD of the wheel so that the tires will stay on and the OD of the mounted tire will usually be the same as a stock tire for a particular car. If you put a tire on a different diameter wheel the mounted diameter could be bigger or smaller. If you put a tire on a taperd wheel the tire might also have a taper, but I don't think that a very slight taper would affect performance.


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## Grandcheapskate (Jan 5, 2006)

I was surprised at the difference in rear wheel size I found on the Lifelike M chassis. I did find other chassis types with slight variations but I think the span from smallest to largest M chassis wheel was the most significant.

I doubt this could have been from just a variation in shrinkage out of the same mold...unless they used different materials, with different shrinkage rates, at different times.

So what is the "standard" I.D. for a replacement Lifelike tire? The stock replacement tires I have for Lifelike allow a 15/64" (.234") drill bit to pass through but not a 1/4" (.250") bit. Which kinds of goes back to my previous comment about the I.D. of the tire needing to be smaller than the smallest rear wheel O.D., which in this case would be .277".

Joe


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## SuperDave321 (Mar 10, 2015)

Just a guess but the wheel taper would make it easier to remove them from the mold.


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## Grandcheapskate (Jan 5, 2006)

I have the chart pretty much complete. All my measurements were done with a manual Micrometer so they may be off a little, but certainly close enough for toy cars.

I don't how to post it here in a readable format (it is in an Excel spreadsheet). If someone can tell me how to convert it from Excel to something I can post here, send me a PM.

Thanks...Joe


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## alpink (Aug 22, 2010)

you might find that this site is what you need

https://www.dropbox.com/gs?oref=e

.


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## Grandcheapskate (Jan 5, 2006)

alpink said:


> you might find that this site is what you need
> 
> https://www.dropbox.com/gs?oref=e
> 
> .


Thanks for the link Al, but I want to stay away from any more websites where I need to join.

I have a question on wheels. During my measurements, I came up with a few different O.D.s and widths spread across Aurora, Tyco, Tomy and Lifelike. I would like to know the "standard" O.D.s and widths for which there are common tires available. 

My measurements show basically one front axle size: .047"

Front wheel O.D./width combinations are:

Tyco Narrow Pan: .255"/.205"
Lifelike M/T: .276"./.180"
Tyco HP-7/Wide Pan: .280"/.205"
Tomy Turbo: .295"/.175"
Tomy SG+: .295"/.185"

Rear axle sizes are:
.059" (Tyco)
.062" (Lifelike, Tomy Turbo)
.065" (Aurora, Tomy SG+)

Rear wheel O.D./width combinations are:

Tyco 440: .255"/.305"
Tyco HP-7: .280"/.215"
Lifelike M: .276"./.305"
Lifelike M/T: .284"./.305"
Tomy Turbo: .276"/.255"
Tomy SG+: .342"/.255"

So what are the most common tire sizes and which O.D. and width combination do they work with? In other words, if you were going to make generic rear wheels to work across all these brands, what size(s) would you do?

Thanks...Joe


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## Frank Broughton (Jan 31, 2016)

Grandcheapskate said:


> I was surprised at the difference in rear wheel size (snip)...
> 
> Joe


Plastics and thousands of an inch -- can it ever get that accurate?


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## Frank Broughton (Jan 31, 2016)

Grandcheapskate said:


> I have the chart pretty much complete. All my measurements were done with a manual Micrometer so they may be off a little, but certainly close enough for toy cars.
> 
> I don't how to post it here in a readable format (it is in an Excel spreadsheet). If someone can tell me how to convert it from Excel to something I can post here, send me a PM.
> 
> Thanks...Joe


Google sheets! http://www.google.com/sheets/about/?gclid=CM_OlsfZ0ssCFYI9gQod6VUGHA


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