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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!


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Old 01-29-2007, 10:51 PM   #23431
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Sorry but you don't have that all correct. Gil Losi, Jr. won the "85" worlds in Modified with a Yokomo Dogfighter. I have a professionally produced video from that race and I visited the "Ranch Pit shop" a couple of times and they used to show the actually winning car in a case as if straight off the track. Jay was using a special AE RC10 4wd that was actually never sold. The video had interviews and closeups of the cars. That is why AE doesn't give credit to Jr for the worlds.

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Old 01-29-2007, 11:09 PM   #23432
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thanks for the correction, i thought it was Losi Jr. that was using the RC10 that was 4wd. but he did win as a AE driver just as other AE drivers have won in 4wd classes using non-AE cars.
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Old 01-30-2007, 12:03 AM   #23433
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Originally Posted by jrrc
See the 12th scale museum mentioned earlier for the first t-bar car, the "Delta Super Phaser". It was introduced by Delta Mfg. (in Iowa) for the first IFMAR 12th scale Worlds in 1982 (four years before the 12L)....which it won with Art Carbonnel driving. And yes, I was there.
I to was there an indapedent with a lighting 2000 it was fun to watch that final .
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Old 01-30-2007, 03:37 AM   #23434
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Originally Posted by dr_hfuhuhurr
I found this REALLY interesting. Do the front axles for this HPI car look familiar? Anyone with a GenX recognize them?


I just hope that the CRC ones don't suffer from the same issue as the HPI one. The HPI assembly would develop a large amount of slop after a short period of usage.

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Old 01-30-2007, 05:59 AM   #23435
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Originally Posted by THE DARKSIDE
I just hope that the CRC ones don't suffer from the same issue as the HPI one. The HPI assembly would develop a large amount of slop after a short period of usage.

Yup I brougth that up in the CRC thread here and on CRC's web site. They claim it will not though because CRC is using a stiffer plastic where HPI's plastic was very flexible.
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Old 01-30-2007, 06:59 AM   #23436
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Default 1/12 tire only

Hi there i was wondering if you guys could help me ??

After an absence of 15 years, I going to start 1/12 scale racing again, using my original 12L which I purchase in 1990, Now I am looking to get some new tires for this car, but it seems now that you have to buy the wheels and tires as a package,

Is it possible for me to just get the tires only ???

And do the jaco wheels etc fit my car ??

thanks Kevin
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Old 01-30-2007, 07:03 AM   #23437
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I think either TM tires or maybe BSR tires are still molded for the two bolt hubs. I'm sure someone will post a link?
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Old 01-30-2007, 07:17 AM   #23438
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All things staying equal, what should a long t-bar (longer than a standard AE .075 t-bar) do for the handling of a 1:12 scale?
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Old 01-30-2007, 08:59 AM   #23439
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you may want to ask Josh C. at CEFX about that one. i beleive the first CEFX C-12 had a longer t-bar like that of a 1/10th pan car.

when i was recently building up the latest C-12 with AE front, i noticed the t-bar was shorter than a 12th AE t-bar and the rear pivot was farther back. i also noticed more holes for other t-bar lenghts. so i emailed and got this response:

The C12 rear pod is much longer than an AE pod to allow for a larger range
of gear selections. With the pivot moved back, this gets the geometry back
correct so we have the shorter pod geometry. We have the other holes so you can use AE t-bars or the CEFX short, med, long. The kit now comes with the medium. The longer t-bar reacts slower and is easier to drive but lacks steering and a quick change of direction. It is very good on high speed, flowing tracks or ones that are really bumpy. The medium has a similar feel to driving an AE car. The short is really quick and almost twitchy to drive. It was intended for asphalt racing where sometimes you need to run a very short t-bar to generate enough steering and quick responce on a slippery surface.
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Old 01-30-2007, 10:25 AM   #23440
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I was thinking that it would make it react slower, but just wanted to see what others thought. Thanks for sharing the info.
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Old 01-30-2007, 10:44 AM   #23441
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I'm relatively new to 1/12 racing and was wondering how much exponential to dial in for ST and TH on a short carpet track running stock a stock motor. I'm using a JR XR3i for now. So far, I've been running ST and TH linear for the my first few races and plan to start using a little negative, maybe -20, on the steering to calm the car down a bit. But for throttle I'm not sure what will result in a faster car. My gut says go positive on the throttle. Any comments?
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Old 01-30-2007, 11:48 AM   #23442
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I'm fairly new to 1/12th as well but I run only about 5-10% neg. expo on steering. I tried more but I really felt like I had to crank the wheel to get the car to turn in properly. The other thing I started running was creep. Just enough so the car will roll on its own at neutral. That was the number one thing that made me more consistent. Flow through the corners was much better and I could carry a lot more speed.
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Old 01-30-2007, 12:45 PM   #23443
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I always believed that the 12'L' was because Gil Losi developed that car, but that it was because he was the first to put a Delta 'T-bar' rear end onto the Associated 'old-skool' front end, combined with the aforesaid wider stance to the chassis. Certainly I never saw such a combination raced, or pictured, anywhere, until Gil did it.

Yes, the C12 did have a different position for the rear T-bar pivot, but the T-bar was the same length as an Associated T-bar. We used to run our C12s with an AE T-bar and it ran better! The trick with the C12 was to lower the front wishbone pivots by 0.020", and then it really flew! However, no one is ever going to get a car to handle with semi-trailing front suspension, so the C12, and the new Corally SP12X won't feature against an AE dynamic strut front end - ask David Spashett!!
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Old 01-30-2007, 01:38 PM   #23444
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Originally Posted by Apex
All things staying equal, what should a long t-bar (longer than a standard AE .075 t-bar) do for the handling of a 1:12 scale?
If all things were exactly equal, except for the length, I would suspect the car would be tighter. More weight transfer under power and deceleration. The car will flex more front to back and the result on the rear of the car would be the T-bar would feel thinner, side to side. More chassis movement. The center shock and spring would become more critical in the equation, and have a larger impact.
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Old 01-30-2007, 04:20 PM   #23445
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Originally Posted by THE DARKSIDE
I just hope that the CRC ones don't suffer from the same issue as the HPI one. The HPI assembly would develop a large amount of slop after a short period of usage.

on the hpi one's the king pin's are not threaded in so they got slopy fast.the gen x one's are threaded and set screwed.
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