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This is a place to share knowledge related to 1/12th scale racing. It is not to be used for conversations.

Click links to go to manufacturer product page. If any are missing please add them!

Pre-mounted tires readily available in the US:
Pre-mounted tires readily available in the Europe:
  • Hot Race ??

Gluing your own donuts:
https://www.youtube.com/watch?v=hm7z1rz-74s - Special thanks to Edward Pickering!
Truing tires:
https://www.youtube.com/watch?v=8wqHOLWq6Uc - Special thanks to Edward Pickering!

The following information came from HERE, with some editing and information added. Thanks Christian!


BSR, CRC, Jaco:
Pro One is no longer selling to the public, but it and the brands above are all mounted by BSR and use the same foam. The nomenclature of the BSR vs Jaco/CRC is a little different in a few instances but is otherwise the same. The BSR foam consists of three families, and can be identifed as synthetics, naturals, and blends.

Synthetics - The old school, light weight, easy to true "dry feeling" tires. These include tires like CRC/Jaco Yellow (BSR White), Black, Gray, etc. These tires offer the highest wear rate and lowest grip. Many racers continue to use these nder high bite conditions.

Naturals - These tires are usually the best alternative for low bite and asphalt. They include Pink, Magenta, Double Pink, Lilac (BSR Team Purple), Purple, and other tires. These tires provide a ton of grip, but tend to get sticky in high bite conditions. This rubber does not wear as easily, and the cars will pick up gunk and fibers from the carpet under most high bite conditions. This is especially bad if the humidity is high.

Blends - These are the tires most people run today. They were initially called "JFT foam" by some, as it was believed that the tires were the same as the JFT tires. We can divide the blends further into two groups: high rubber and low rubber content. The high rubber would be the new rear Orange and Red from the BSR family, and the low rubber would be the Green and Blue varieties. When, asked about the difference, John Foister from BSR Tires said they came from the same "family" of foam, but they offered different grip. According to John, the Green/Blue has more bite than Orange/Red, but from track testing Oranges offer more bite than Green (being equivalent to in hardness) when the grip is high and absolutely no grip when it is lower. The Orange foam has a denser pore structure and the tire is not as prone to chunking. It is also important to note is that BSR Blue rears are not the same as the BSR Blue fronts!

JFT stands for Japan Foam Tire. They started the new wave of foam tires we are all using now (Blue/Blu, Green/Greene, Dbl Blue, etc). These tires are a little different than the BSR tire family, but work in very similar conditions. They offers four varieties A (asphalt), C (carpet), S (???), and R (???). This does not mean that those types only work on that surface, but this is what they recommend.

JFT uses the same foam for fronts and rears if the color is the same.

A: Used on asphalt, considered close to the natural rubber variety and are named consistently with other natural tires.
C: Used on carpet, considered a blend.
S: Used on carpet?, tires are ???
R: Used on carpet?, tires are ???

For setup, the JFT foam seem to generate more bite than the BSR, therefore the car tends to be a little more aggressive.

Ulti is another Japanese brand that offers an array of compounds. They have their own way of rating tires, and are difficult to equate to other brands. They have 4 different varieties, each in varying degrees of hardness.

J: High rubber content tire, similar to Pink/ Magenta. Soft would be close to a pink. These offer the most bite and are great for asphalt/carpet front tire. (J hard being very popular)
X: "Balanced" blend, similar to JFT Blue/ Green. Soft is equivalent to Green, medium to Blue in hardness. Great for carpet!
Y: High synthetic blend with lower grip, and is not a very popular variety.
Z: A very expensive "special" foam that is supposed to be magic on asphalt. Only make it in soft shore.
European tires:
There are many great European foam tire brands that use their own types of foam, as well as traditional foams. SOmeone with more knowledge about them will need to fill this in!

Tire Diameter:
If you are racing on carpet, you have to evaluate how much grip your track has. If your track is low to medium grip, you can run bigger tires. If you are on higher bite you have to cut them smaller, there is simply no way around it. Bigger tires are needed for asphalt, especially in the rear. The larger tires provide much needed lateral bite.

Carpet (mm):
Low - Medium Bite
Front: 42.0 - 42.5
Rear: 42.5 - 43.00
Medium - High Bite
Front: 40.5 - 41.0
Rear: 41.5 - 42.0
Big Race
Front: 39.5 - 40.0
Rear: 40.5 - 41.0
Asphalt (mm):
Parking Lot
Front: 43.0 - 44.0
Rear: 44.0 - 45.0
Prepped High Bite
Front: 42.0 - 43.0
Rear: 43.0 - 44.0

Tire Saucing:
Most facilities have moved towards odorless traction additives such as SXT. Some of additives evaporate very quickly and some do not. This seems to be something that is also dependent on tire compound and ambient temperature. For example, saucing a Green compound seems like it never dries, especially when tjhe temperature is lower. We have found that wiping the tires off 15 minutes before we go run allows the sauce to cure, which makes the car come in much quicker with Green rears. Blue compounds on the other hand, do fine when wiped off right before hitting the track.

Saucing half front and full rear is a good initial starting point. If the front of the car is too agressive you can sauce les than half, or for a shorter amount of time.
Tire Fuzzing:
In conditions of increasing grip, foam tires will somewtimes get sticky and pick up fuzz and debris from the track. This is highly dependent on the rubber sedan tire that is being run at your local track and the compound/ type of foam you are running on you car. The softer the sedan tire and the harder/higher rubber content in your foam tire, trouble with fuzzing seems more likely to occur.

There are ways to get around fuzzing under most conditions, and usually involves the selection of the correct foam compound. The more fuzz you get, the softer/lower rubber content you want to run.

Problem: Car fuzzes with Lilac/Team Purple fronts and car starts pushing.
Solution: Use a softer front tire and or different family of foam. Replace it with Blue or Double Blue front.

Problem: Car loses rear bite 6 minutes into the run. Blue rear tires look almost clean but have small carpet hairs.
Solution: Use Green rear tires. The softer compound wears instead of getting sticky, minimizing fuzz.

Tire Selection:
Starting out, pick 2 tire compounds for the front and rear. The following should have you covered 99% of the time.

Front - Green and Blue (BSR) or Green and Light Blue (JFT)
Rear - Blue and Double Blue (BSR) or Blue and Dark Blue (JFT)

You may wonder about other compounds out there and if they might be better, trust me, they probably won't be. Even if there are other tires that can be as fast, the synthetic family wears out really fast and the high natural rubber will probably fuzz on you over an 8 minute run. The blends family seems to be the most versatile foam type available today. They last awhile, and sticking to them will make your process of tire selection simpler.
Tire Charts:



JFT (Japan Foam Tire)


Enneti (Xceed)

As of now, ROAR is staying 1S (3.7V nominal; 4.2V fully charged) for 1/12. There are many 1S ESC's with a built in BEC so nothing else is required to power the receiver and servo.

If you don't want to lock yourself into a 1S specific ESC, you do have other options! It is possible to use your 2S ESC without a booster or receiver pack, and the ESC simply supplies the lower voltage. If that does not appeal to you, you will need to use an Rx pack or booster. The Rx pack and booster will both supply the receiver with a higher voltage than the 1S pack.


If you choose to use a voltage booster, it works exactly how it sounds. Instead of plugging the ESC into the receiver, it plugs into the booster, and the booster plug goes to the ESC, supplying the higher voltage.

If there are any missing please add them!!

If anyone would like a need for a chart comparing the ESC's specs PM fenton06 and I'll get one made and put in here!
Voltage Boosters:
If there are any missing please add them!
Black Art (CRC - US Dist):
  • Audi R8C - BA002 - .020 Thick

  • Black Market (Mohawk 12) - BA005 - .020

  • Lola B10 - BA006 - .020 thick
  • Toyota TS030 - BA008 - .020 thick

    Lola - black/red, TS030 - green/pink


Reflex Racing/RSD:


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Old 04-02-2004, 08:08 AM   #7381
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Several months ago I started a discussion about using a capacitor with your speed control to enhance motor performance. I ran the 4700 picofarad cap from Novak on my speedo at the carpet on-road nats. My speed contol is a LRP Quantum2. I found no difference in performance for that speed control with or without the capacitor. It could be that the Quantum2 doesn't need one. I see all the Novak speed controls require one. Anybody else notice the same thing?
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Old 04-02-2004, 08:17 AM   #7382
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yeah I have. They had a lot of problems with the GT7's blowing up when they first came out. They are not doing it for the "performance" increase, but to try to keep their circuitry from overloading.

However, if you look at the stock A main at the roar nats... there were a LOT of them in that main
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Old 04-02-2004, 09:08 AM   #7383
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More caps more rip we run one in 1/12 and two in touring it is hard to notice the difference but it is for sure there all a cap does is store power if u un solder your batts and turn your speedo on your speedo will try to come on because of the stored power in the cap and for the speedo blowing up that has noting to do with the cap
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Old 04-02-2004, 10:29 AM   #7384
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It doesn't surprise me that you wouldn't see any difference with a 4700pf cap. That is such little capacitance that it isn't storing any noticable voltage. Try something bigger. Novak sells caps that are around an inch long and 5/8" thick that aren't super heavy. That may give you a bit more squirt. I'm not exactly sure what the capacitance is on those, but it's in the microfarad range, so it's many orders of magnitude more capacitance than what you're running. Just make sure you wire the cap correctly (observe polarity) and use a minimum of a 10V cap. Large electrolytic caps do explode if you use them incorrectly.

The theory of using a capacitor is that it's effective internal resistance is lower than that of the battery, so it is able to deliver voltage more quickly to the speed control. It also, in theory, acts as a sort of voltage reserve that reduces the low voltage spikes that you get when you have a sudden burst of current, such as jumping on the throttle hard after exiting a hairpin. Again, this is all theory and whether that theory translates into actual improvements in laptimes is a subject of great debate.

In my experience, the only advantage that I have found is that it helps reduce the chances that the speed control will go into thermal protection when racing on a hot day of racing outdoors. The best I can tell, the theory of smoothing out the low voltage peaks would be the explaination, but then again, it could also be my imagination!
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Old 04-02-2004, 11:55 AM   #7385
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The power cap is there to help clean up the square wave used to turn the FET's on and off. None of the caps that we use have enough capacity to actually turn a motor over let alone make a differance that you can feel.

What we feel is the increase in efficiency of the switching. The better switching is also why the speedo runs cooler.
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Old 04-02-2004, 12:12 PM   #7386
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Default Parts for switchblade?!?!!

hey guys...i'm looking for a site that carries parts for the trinity switchblade. So far i've found nothing, and all I really need is a spur gear and servo mounts. any help would be greatly appreciated, thanks!
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Old 04-02-2004, 03:11 PM   #7387
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I can feel the difference with the power cap on. Its at part throttle though. To me it feels like you turned up the throttle trim. It has no use at full throttle in my opinion any how. Yes it smooths out the power coming out of the batteries and into the speedo. It will do nothing when you Yank the throttle to full. It will help your batteries and speedo get along better. I also think it helps with glitching if you do not use a reciever pack.

David Root
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Old 04-02-2004, 03:38 PM   #7388
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psyco - glad to see you jumped in. I remember in the earlier discussion about the capacitor that someone, maybe you, offered a part number and associated that part number with Digikey. I looked it up and couldn't find the part. Some of the electronic parts people became annoyed with me as I asked questions trying to get that capacitor. Any ideas?

DavidR - I will say now that I noticed an increase in speed at less than 1/2 throttle. It happened when I set the car down to drive over to the start line. I did not notice any performance gain at any other time. I think you hit on the answer. Once again, I didn't experience any better lap times with the capacitor on the Quantum2. I tried it both with and without during practice.

Drew - duh!? (hahaha)

All - I started using the capacitor to keep the voltage level to the speed control, receiver and servo up to a level for good performance. I thought it might eliminate some glitching, but I have discovered that other things do that and the capacitor makes no difference. I also used it in 2002 to keep enough voltage in the personal transponder so it would work reliably. That doesn't seem necessary, either.

Thanks for all comments and I hope this has helped others as well as me. If anyone learns something that hasn't been mentioned, please bring it up.
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Old 04-03-2004, 03:18 AM   #7389
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Default DavidL

For once I get to help you !

Digikey P10264-ND 4700 Uf, 16 volt, 105 C. They have a $5.00 charge for orders under $20.00 so I ended up with about 14 of them for $25.00 they ship right away too. These are .71 around by 1.04 long.

In MY opinion, they do help with glitching and part throttle. I do not know about a cooler running ESC, but should. I use them on some ESCs and not others.

David Root

Edit: Here is the link


Last edited by David Root; 04-03-2004 at 03:24 AM.
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Old 04-04-2004, 08:49 AM   #7390
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I made an error earlier when discribing the capacitor I used. It is 4700 microfarad. This is the standard part from Novak. This brings up another question for David Root. What is the difference between this capacitor and the one you bought from Digikey?
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Old 04-04-2004, 09:10 AM   #7391
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Cool Aboout $5.00?

I think the cap I buy from digikey is a High Frequency, Low impedence cap, Type FC. I doubt there is much difference at all. From what I understand, the ones you buy at Radio Shack are of lower quality and frequency. Here is a Quote directly from Novak site.:

This text is a reprint of an internet posting, dated February 6, 1997.
The Cyclone speed control uses extremely high-speed switching circuitry for the drive power MOSFETS, which are used to control the power to the motor. This method of control is called PWM (pulse width modulation). To deliver 50% power to the motor at a PWM frequency of 5000 Hz, power is applied for 200 micro-seconds (Ás) and then turned off for 200Ás, repeatedly. In between being turned on and off, the transistors go through a transition period where they are inefficient. To minimize this inefficient period, the transistors must be switched on and off at a fast rate. Therefore, the speed of switching, which determines the overall efficiency of the speed controller, is important to the design of the speed control. The cyclone's switching speeds are the fastest in the industry, with a Rise Time (off to fully on) of less than 1 Ás and a Fall Time (fully on to off) of less than 0.8Ás.
There are several side effects with high speed switching. The more dangerous of these effects are the creation of high voltage spikes and radio noise. The value of these voltage spikes is determined by the current draw, the internal impedance of the battery, and the length of the wire connecting the speed control to the battery. During PWM switching, the battery voltage fluctuates up and down several volts (sometimes decreasing down to just a few volts during heavy acceleration). This fluctuation is called "ripple voltage," and can damage or cause improper operation of the radio system.
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Old 04-04-2004, 09:11 AM   #7392
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To provide smooth power to the speed control and the rest of the radio system, a very low impedance high-frequency capacitor is placed across the battery wires. This capacitor also delivers a large surge current during the valley portion of the ripple. Our test results have shown that at 50% power level, the use of a power capacitor adds about a 7-10% increase in motor RPM, reduces radio noise and increases the radio range. When the power capacitor is properly performing, it gets hot and must dissipate this heat or it will fail. As you have observed, the power capacitor is round in shape. Therefore, placing it inside the speed control would waste a large amount of space and prevent the heat from being dissipated.
Our competition uses several low frequency small capacitors, lined in parallel, inside their speed control to perform a similar function. We felt that doing this would reduce the system's reliability, as heat builds up in these capacitors and they tend to overload and fail. Our design philosophy delivers by far the best solution to this problem and provides flexibility in the usage of available space.
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Old 04-04-2004, 02:11 PM   #7393
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Default TRC vs Jaco foam

Just wondering if you guys notice a difference between ( Jaco pink rears and Jaco purple fronts) versus (TRC pink rears and TRC purple fronts) on 12th scale cars. Basically a comparison between Jaco and TRC. Thanks.
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Old 04-04-2004, 02:29 PM   #7394
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maximum- The Jaco wheels are much stiffer than the new TRC so they feel more consistent. I say Jaco or BSR, never run TRC unless they find a rim that dosn't flex as much.
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Old 04-04-2004, 04:50 PM   #7395
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DavidR - Thaks for providing that information. I now know that I have used the low impedance, high frequency capable capacitor and know the results of comparisons between using it and not using it. By the way, Digikey is not the manufacturer of the capacitor you mentioned. They are only the distributor.
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