# Aurora Sheriff's Car Front Tires



## Grandcheapskate (Jan 5, 2006)

Hi Guys, 
I have an original Aurora Sheriff's car which is sitting on the special magna-traction chassis with the bubblegum lights. The chassis still has the original front tires which are the wide, low profile variety - not the more common, taller O-Ring version. These are the tires that came on the G+ cars; I'm guessing Aurora started putting these on AFX chassis once the G+ came out.

The Sheriff's car front wheel wells do not allow me to install the taller O-Ring front tires because there is not enough clearance. However, the lower profile tires will not touch the track; the tires are not tall enough for fully compressed pickup shoes when the shoes are on the rails. I've noticed that the Aurora 4 gear chassis I have (picked up at a show - may be used) also use that same G+ tire but don't have same problem. Why just this one chassis has a problem I cannot understand. 

At first, I discovered I had to remove a bit of plastic on the underside of the chassis. With the low profile tires, the chassis was hitting the track in the area right in front of the "Made in Singapore" lettering. Once I filed off some plastic, the tires contacted the ground when placed on a piece of glass with the guide pin removed. 

However, if you place the chassis on the track with the pickup shoes on the rails (no guide pin installed), the tires do not touch the track. The little bit of extra height of the rails is enough to lift the front end. If I remove the body and install standard O-Rings, the chassis runs great. 

The chassis uses short step pickup shoes. I tried it with ski shoes and it made no difference - in fact, it may have been worse. 

I don't want to alter the body in any way. Is this a common problem? What are my options? Is my only option to grind down some O-Rings until they fit under the wheel wells?

The O-Rings I'm using are a little taller than the original AFX Goodyear front tires and they work great, even better than the originals. I guess it's possible that an original AFX front tire may also work, but after all these years, most are hard as a rock.

Thanks...Joe


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## kcl (Dec 27, 2009)

Joe

These are the tires that belong on that chassis
















They are slightly larger than the G-Plus tires and have a small rib on them
just enough to touch the track. Also they have a groove inside that fits
the rib on the wheel so they can't fall off.

kcl


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## Grandcheapskate (Jan 5, 2006)

KCL,
Those are exactly the tires which are on this chassis, yet they do not touch the track. In fact, my car has the same style pickup shoes as in your picture. The tires look nearly new.

Note in your first picture, there is a small circle molded into the chassis right behind the guide pin. I had to file that section down a bit as it was hitting the surface when I placed the chassis on a piece of glass. Before I filed that down, the tires did not touch the glass. That's how low these tires are. Right now, that whole area of the chassis is real close to the track when using these tires.

The wheel wells do not leave a lot of room for a taller tire. This is really cutting the tolerances close.

Thanks...Joe


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## kcl (Dec 27, 2009)

Joe

After looking at several different cars I find that there are
different styles of that type of tire. One is a little larger in
diameter and has a larger rib on it than the ones on the
car. I don't know the exact size but I know they are taller.
I think they are older tires , they also have GoodYear on them.
Perhaps you can find a set of those and may solve your 
problem.

kcl


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## Grandcheapskate (Jan 5, 2006)

KCL,
I looked through my excess tires and could not find another tire that would fit under the wheel wells and yet be tall enough to let the chassis run correctly. It seems the only solution is to open the front wheel wells to get enough clearance for a taller tire. Hard to believe there is so little tolerance in this front end. I really don't want to alter the body, so this car may never be able to run.

One thing I noticed today that I had never noticed before. I thought all Aurora AFX chassis used the independant front end - where one hub was loose on the axle and the other hub was pressed on, the axle having a head on one end. In looking at this chassis and all my four gear, I see that there is a different axle setup where both hubs are pressed onto the axle like a T-Jet. I have a few Magna-Traction AFX with this same setup.

When did Aurora switch over to the non-independant front wheels? It seems these types of axles use the lower profile, ribbed front tires, although you can use a standard O-Ring if the clearance is there.

Thanks...Joe


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## kcl (Dec 27, 2009)

Joe

When aurora went to the slotted mag,turbine and steel type wheels
they stopped being independent. Just what time frame that was I
don't know. It would be a shame to cut the body though. I have
some that are new in the package that appear to be taller.
They are in original AFX package never opened although the
rear tires don't look to be much good. If you would like to try 
them before you cut the body, PM me with your address and
I'll send them to you. Just a thought but maybe with age the
tires shrunk even though they look new?

kcl


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## plymouth71 (Dec 14, 2009)

Heres a side profile I have of 2 different AFX front Tires


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## alpink (Aug 22, 2010)

don't cut the body. we will find a solution without that.


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## TGM2054 (May 14, 2011)

Could you just pull the wheels off and file the backside of the hub off a little so the wheel sits closer to the chassis. I do this on my drag cars to get the tires in closer to the chassis so I can drop the nose of the car down. Just a thought.


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## Bill Hall (Jan 6, 2007)

alpink said:


> don't cut the body. we will find a solution without that.


AGREED!

What's the rush to gash it? How about some pix?


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## Grandcheapskate (Jan 5, 2006)

KCL,
Thanks for the offer. There's no need to send me another pair of tires as I found some larger ones on the four gear chassis - tires which are as big as I can go.


Hi Guys,
I won't be cutting the body. I'm much more a collector than racer. If all else fails, I'll just eventually put it in a display case.

I'll try to post a couple pics if I can. Yesterday I took the front tires off one of my four gear chassis whose tires are just a hair taller than those on the Sheriff's car.

While they are the same type of tire, this pair was slightly larger. I put them on the Sheriff's car and it ran a little better but they barely touched the track, and only in spots. I'm guessing this may be due to rail height differences. However, this is the tallest tire I will ever be able to put on this car as they completely fill the wheel wells. For the most part, the car is riding on the pickup shoes and not very well.

In looking at the four gear cars, I can see they have a lot more clearance in the wheel wells. It just seems this particular body style doesn't allow for a larger front tire and the one you need to use isn't tall enough.

Thnaks...Joe


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## Bill Hall (Jan 6, 2007)

*I have many questions...lol*

I'm not familar with the underside of this body so I gotta axe a few.

Howz the body fit Joe?

Front stand offs in tact?

Rear standoffs tipping the body forward due to some unseen impingment?

How about the lower collet of the guide pin? Malformed or "puffy"?

Do the wheels touch properly with the shoes removed...or the guide removed?

...or does the chassis still touch?.

Strip the chassis, and drop it on a lil mirror yet? To check for flat.

I love a good slotcar puzzle! :thumbsup:


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## kcl (Dec 27, 2009)

Joe

Took a couple pictures of the same car as in the previous pictures.
It's sitting on a section of aurora lock and joiner track. I checked 
the rail height with a depth mic and it measures between
.012 to .014. 

















Just trying to show chassis clearance and small tires touching and wondering why you have none? Perhaps your rails are higher I 
don't know but was just a thought.

kcl


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## Grandcheapskate (Jan 5, 2006)

Hi Bill,
I will answer your questions in a follow-up post. Just a quick response; the tires do touch the ground if the pickup shoes are not on the rails (ie. on a piece of glass). The height of the rails is enough to lift the car off the track. See KCL's pictures in the previous post and note the completely compressed pickups. There's just no excess room.

KCL,
In looking at the photos of your car, do you see how the pickup shoes are completely compressed? There's absolutely no room left for them to compress. If the rail is any taller, it would lift the front of the car up and the tires wouldn't touch.

I don't have a mic to measure my rail height. I am using the new style Mattel track (and my 6" and 15" curves) which I'm guessing use the same rail height as Tyco.

I will try to get some pics. I just have to get out the camera.

Thanks...Joe


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## NTxSlotCars (May 27, 2008)

I guess this is why most departments switched back to Dodge in the late 70s.





































I always liked the roar of a Mopar cop car.



















Just a Mopar fan...


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## Bill Hall (Jan 6, 2007)

Yuppers, Got it Joe. Thanks KC.

The trick below doesnt really address all the whys and whats....but it does get your car down the track. 

Just "un-restrict" your pick up shoes with some careful file work. Most all pick up shoes have extra meat at the bottom sill that can go away with no ill effects; in fact quite the contrary if it gets ya rolling and handling smoothly. A few thou' is all ya need.

Just take out the face of the bottm sill with a hobby file. I just keep cutting until I start to scratch the topside of the footprint. Then be sure to dress the front edge with a couple of carefully placed cross strokes to clean the leading edge where ya ragged it up with the file.

It's one of my get out of jail tricks after I've gotten too greedy and dumped a chassis too low, like the set up below. While I had some clearance it was proven to be insufficient as the variation in rail height of my sectional track exceeded the clearance; thus creating some quirky handling, because the shoe is pinned between the rail and the chassis. Sorry I dont have a before pic...


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## Grandcheapskate (Jan 5, 2006)

Hi Bill,
That is a great suggestion and seems so obvious. I'll take out the file and start to do a little surgery - hopefully sometime today, but maybe tomorrow, and then report the results. Today I'll try to get out the camera and take some long awaited pics.

We'll have to see if after I give the pickup shoes a little extra room to compress (which means the chassis will get lower) whether the chassis itself hits the track. I already filed a bit off the chassis bottom because I think it was hitting when I tried the chassis on a piece of glass. 

On a somewhat unrelated topic, your picture is a great side shot of how you have the pickup shoe riding on the rail. I see the front of the shoe is a little off the rail and the remainder of the shoe "step" is on the rail. A picture IS worth a thousand words.

Thanks...Joe


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## Bill Hall (Jan 6, 2007)

Joe, I have my fingers crossed that the wheels touch first and the front axle holds the chassis up before you run out of clearance!

...and yes, I bend shoes around whatever way I think they need to be....until I get it right...LOL! The shoe hook bend, the zee bend, the toe roll, and a few others are an everyday part of shoe tuning around here. 

I make a lot of radical alterations in some of my builds, tire sizes up or down, forward and backward body rakes, front and or rear drop axles. Every time I change the chassis geometry beyond the shoe geometry's ability to compensate, I gotta start bending things around. The shoe voodoo is purely out of neccessity. I found out early on that I'd also be altering some shoes if I wanted my stuff to have the looks AND actually work too.

1. I just pick a shoe style that's close and start by twisting the contact patch parallel to the rail...sometimes ya gotta do the full Z bend if you've really monkeyed with tire profiles. 2. Then I adjust the shoe hook to a sane tension....most stuff is way oversprung IMHO. (The drag on the contact patch created by forward motion is where ya really get your current transfer, gunning the shoes down harder just slows ya down!) I only use two types of spring... T-jet and AFX...any adjustment beyond that is done by adjusting the hook 3. Finally I toe roll the front of the contact patch. This makes the clickety clacks go away and prevents those wild blunt force deslots by assisting the contact patch across any rail joint irregularities instead of banging them head on with too much front angle.

For the same reason that any ski has a rolled lead.


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## Rolls (Jan 1, 2010)

Grandcheapskate said:


> On a somewhat unrelated topic, your picture is a great side shot of how you have the pickup shoe riding on the rail. I see the front of the shoe is a little off the rail and the remainder of the shoe "step" is on the rail. A picture IS worth a thousand words.
> 
> Thanks...Joe


I was noticing that exact same thing! 1000 words, for sure!


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## Grandcheapskate (Jan 5, 2006)

To All Who Helped,

I got the car running successfully! But probably not how you would think.

I first took Bill's advice and shaved off some metal from the front of the pickup shoe so there was a little more travel room. I did this with a pair of used ski shoes so that if I messed up, there was nothing to cry about. I installed the shoes and noticed that they would compress to the point where the shoe itself would hit the bottom of the chassis under the front motor magnet - I was at the limit.

The front tires now touched the track!!! Could this be success? Alas, it was not to be. Although the front tires touched the track, the car sometimes barely moved, and then would move in stops and starts. If I took off the body and put on larger fronts, it ran great.

Then, in honor of Monty Python, I tried something completely different. I put a much larger set of rear tires on the car. These tires have a significantly larger diameter and completely fill the rear wheel wells. I put the car on the track and it ran great. I then switched back to the unmodified original pickup shoes and it still ran great, even with the smaller set of low profile fronts. The fronts now touch with the larger rears.

I looked at the tires that were on the car and they are the same as on my other AFX chassis. Apparently with these low profile fronts, you need larger rear tires.

Who woulda thunk it?

Thanks to all for your help.

Joe


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## alpink (Aug 22, 2010)

larger rear tires? ... now, ... why didn't I think of that? ... LOL


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## kcl (Dec 27, 2009)

Joe

Glad you got the problem solved. Another crisis avoided :thumbsup:

kcl


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## NTxSlotCars (May 27, 2008)

Bigger rear tires always help. :thumbsup:


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## plymouth71 (Dec 14, 2009)

Sigh


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## Bill Hall (Jan 6, 2007)

D'doh!


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## Super Coupe (Feb 16, 2010)

That's a funny car.....hahahaha
>Tom<


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## tabcomary (Jun 2, 2010)

We all should have remembered the "big tire solution". After all, as kids we spent a lot of time improving our t-jets by hogging-out the wheel wells and installing A/FX tires! What Fun!!! 
Great Thread Guys!!!!


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## thunderjetgene (Apr 1, 2004)

Hey, Where's the Bluesmobile? (-:


NTxSlotCars said:


> I guess this is why most departments switched back to Dodge in the late 70s.
> 
> 
> 
> ...


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