31 replies to this topic

[pn6]

What kind of foam are they made of? Neoprene, real rubbber? I know a few sources but have no idea what the compounds are. I don't want to sell any I just want some rubber I can mount and true up for my own cars. Someone knows the secret formula!!
 
Most of the ready to run wheels/tires are the wrong size or are on ugly wheels or drag rubber which is too soft. I'd really like to cut my own donuts.

[mreibman]

If it is indeed a "secret" then no one is going to come forth with an answer.

 

HOWEVER, many of the manufacturers of tires sell donuts, some in various sizes and compounds. I think you're much more likely to find success in this route.

 

I wish you the best of luck in your endeavor.

[Mark Onofri]

I hear you. Want to loose your mind and hair? Try to match Cox hubs with Cox (or any) Tyres. It's the same for almost all of the vintage tyres and hubs (in my case all) I've purchased.

[Bill from NH]

Are the hubs too big or too small to fit the tires you bought? If too big, turn them down to a smaller dia. or buy a circular rasp sold by some slot car companies to enlarge the hole dia. in donuts.

[Mark Onofri]

I've had some success with a drum sander on a motor tool and, I've even made a 5/40 adapter for my Huddy. Still, I've been guessing about.
" will these fit ANYTHING?"
I'm sure someone here knows. Even if dozen people each know what a couple a to tree combinations work, we'd all be farther ahead.

[pn6]

Settling for something I dont want or dont want to do isnt what Im about. I had a supplier here but hes dropped off the planet I guess.

[Phil Hackett]

If you have suppliers lined up,  they know what the compound is. Most likely they want *you* to tell them so there's no "confusion". This is where knowing who to send a sample to be analyzed is useful. Look for friends who may have lab access or Google analytical laboratories near you.

[JimR]

I've often day-dreamed about having a sheet of slot car foam and being able to cut out tires of any o.d., i.d., and width. Then again, I've also day-dreamed about me and Mary Ann and nobody else on that damned island...

[James Wendel]

I think some additional detail would be useful from Paul in order to give him meaningful help.

 

So, Paul:

What qualities are you looking for in tire rubber?  You said foam and firmer than "drag rubber".  Anything else?  You said you're not the type of guy to "settle", so you must have some pretty specific requirements.

 

You said that most RTR wheels/tires were not sized for your needs.  What sizes do you need?  (inside and outside diameter plus width)  What kind of cars are you outfitting?  Are these for a racing program?

 

You mentioned ugly factory wheels; you have a fair point.  Have you considered inserts?  You could try a search on this site.  There is some amazing stuff here.

 

You said that you really want to cut your own donuts.  I buy donuts and mount all my own tires and I shudder at the thought of attempting to cut donuts from a sheet of foam.  Have you actually done this successfully?

 

I buy most of my donuts from JK Products, also from Mid-America, and I think I have also used Chicagoland and PCH and even Professor Motor.  Have you checked out their websites?  Maybe shoot them a text or Email and arrange a phone call to discuss your needs.

 

As for the guys suggesting analyzing rubber samples... really?  for what end?  producing custom foam for Paul's personal slot cars?  ... really?

 

Anyway... I hope these questions lead to useful solutions....  And have you tried Wonder Rubber?

[Mark Onofri]

I always dreamed about Jeannie and Ginger,I
would like them anywhere.

[pn6]

Back in the day , mid to late 60's , the fast "kit" cars (Dynamic, LaCuc,Russkit) had "foam" tires that accepted tire goo of different types and worked much better that the "sponge" tires or natural rubber tires being offered. So the compound isn't anything new. Improved upon sure but I've raced RC cars with the same basic type of rubber all through the 70's and 80's and I see premounted slot car tires and donuts today with the same kind rubber.

 

I have a lathe and make my own wheels for my "project" slot cars. Right now I'm doing a Porsche Carrera 6 bodied car and made the wheels for the Russkit wheel inserts I have. Yes I could've scoured Electric Dreams or Ebay for Russkit wheels but why when I can make my own. So while the rubber sizes available aren't too critical and the compound shore number isn't too critical (I'm not racing these cars, just playing with them) it would be nice to have some rubber that I can cut up for whatever I'm doing at the time that will work reasonably well on the track.

I'm assuming that "wonder" rubber is probably similar to the tires we used on the 1/8 scale "gas" cars. Good traction and better tire wear. I think they had more"rubber" in the compound because they needed to warm up on the track for maximum grip. 

 

My "supplier" is a fellow Slotblogger that was buying sheets of rubber and would cut donuts to size for me. Mostly .410 id x 1.25 od x at least .75 wide. Usually they came over 1 1/4 wide so sometimes I could get 2 donuts out of one. I've contacted him but no response unfortunately. I'm sure this was a hobby thing for him as it is for all of us so he may have moved on.

[Thom]

Have you ever tried looking at the hobby shop for RC plane landing gear tires. We had a 1/24th drag strip here in Omaha and I wanted some tires for a vintage rail and a big tire class. I found Dave Brown Products “lite flight wheels” and cut them down to size. They worked great with goo, seemed to have bigger pores to hold the glue.

[Mark Onofri]

In 2003-4 I bought a sheet of 24 pair? Of Parma doughnuts. It was about $6.00 wholesale/$12.50 retail. I'll post a picture later. Still haven't used them all.
The compound is satisfactory but, the size is awkward. There's a lot of waist and some hubs just won't fit.

[Bill from NH]

Thorn, at one-time, German Graupner rubber from aircraft tires was "the rubber" to use for slot car drag racing. Well-stocked RC shops in the US should still carry it.

[Dave Crevie]

Cox and/or Ruskit even made special wheels to use those donuts. They had a hollowed out inner profile to match the shape of the airplane tires.

[pn6]

Still not giving up on this quest but I found JK selling some Natural tires with a small enough hole and large enough od that should grow big enough when mounted on my wheels to get me to scale size. These will hold me over until I find what Im looking formy wife has a gardening knee pad that looks promising but its bluestillI wonder if shell notice a piece missing? Maybe they make it in blackI have some old thick flip flops that could be the missing link as well..

[Bill from NH]

An Ohio friend once gave me a 1/12 scale RC tire foam inner liner to try. It cut okay with an arch punch but I didn't used them because  they seened too stiff, but they were black. This was about 20 years ago. I have no knowledge if these foam inner liners are still available or if their rubber is/was available in sheets. My kneeling pad is blue like your wife's. It seems soft enough for donuts. 

[Dave Crevie]

These are the wheels I was referring to. The German rubber is stiffer, but we used them because the softer tires tended to explode. The natural JK donuts are what I use for all my old timey restorations. Work perfectly by my judgement.

 

[pn6]

Bill I raced 1/12 scale for years and those liners you refer to were probably the actual tire that we used. That rubber is probably the same thing used in natural or whatever the next guy calls them tires.

[Mark Onofri]

Armaflex is the closest thing I've found. The the sheet stock that I use is a little too low density and high density is in round.
I've been meaning to get the high density sheet , oh since 80 or so. I'll try to get the Parma photo out tonight or tomorrow.

[Bill from NH]

Armaflex = pipe insulation, or another material.?

[Mark Onofri]

Pipe insulation. They have it for other uses but, I've just used it for Pipe

[Bill from NH]

I have lengths for 3/4" pipe, Foam King advertises some for 1/2" copper that may be more donut size. 3/8" might be even better if it was available.. 

[Phil Hackett]

Pipe insulation. They have it for other uses but, I've just used it for Pipe

This is what the original SBR from Rubatex was used for. It also met the needs of slot cars for many years.

 

Somewhere in the vast (j/k) Sonic facility there exists a die that cuts donuts with a small hole (1/4" if I remember correctly) for .300 diameter wheels. Some day I might post a picture of it....

[grooverunner]

Phil,
If you could show a picture of it, I love to see it! Tools, dies and jigs to build and make things are very interesting to me and I'm sure others on here also.
Ken