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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 05-26-2003, 05:31 AM   #3031
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the old school, retro whatever front end are the same most likely. and both of them are the exact same as the AE old front end (before the dynamic strut).

thebigbull- you bought an "expearianced" (or at least thats what they call used golf balls, lol, and it sounds better) rev. 3. The merchant doesnt have a traditional manual, but more a sheet that describes how to build everything, however the whole car is pretty self-explanitory, and if you have any problems with stuff like building the rear axle, you can just download an AE RC12l3 manual since the rear pod and axle is the same.
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Old 05-26-2003, 09:50 AM   #3032
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Default do it!

The retro front end is exactly the same parts as the old skool front end. "old skool" is a term coined by Speedmerchant. All the manufacturers get this stuff from AE, the original manufacturer.

The CRC car listed with the retro front end and 3 bolt rears is the car you are saying you want.

I use a .125" drill and a 60 degree countersink to mount the servo.

If you are really worried about having comprehensive instructions, you should get a 12L3. AE has the best instruction book by far. The Rev3 instructions are one page and little more than set up tips (no front end directions). The CRC manual is better with copies of the AE instructions for the front end and shock. That being said, you can find almost all this stuff on line and down load it.

By the way, when I bought my first 12th scale car ( a 12i clone) it had no instructions at all. They just handed me a box of parts and said "have fun". Now this is back when 12th scale cars were made out of plywood and rocks, but my point is that sometimes you just need to trust your modeling skills and jump in.

Sheldon's probably has the small size servo saver but I don't know if they list it online. I think I got some from Hobby Etc.

Now...just go buy a car !! You will have plenty of questions once you start building it.
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Old 05-26-2003, 09:59 AM   #3033
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Default Rollout

Try a rollout at about 35 for the 12x2. I use 36 or so with a 12x3 with 3300s and a reciever pack. I'm sure your exact rollout will be a little different, but that's a start.

When I go up or down a turn I usually change the pinion one tooth, which is less than 2 mm with small tires.
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Old 05-26-2003, 10:06 AM   #3034
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Lonestar, There aren't amny people that run 6 cell mod. With 4 cell i would usually aim for about 40mmpr with a 12 turn. I would go with about 2mm per wind. I am not sure if this is any help as like i say i have never used 6 cell.
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Old 05-26-2003, 10:18 AM   #3035
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Exclamation Retro


Retro,old school, and old style , I'm sure are all the old style associated front suspension. Like the origial 12LW and 1/10 associated pancars. If you look closely at the different pictures on CRC or Speed Merchant web site you can see the difference. I swithched from an L3 last winter to a carpet knife. I wanted to try something different (SICK OF TAPING BATTERIES), and I bought The Boody Knife(THe RED EYE CANDY I HAD TO HAVE). Get the XTRA shock and tweek springs right away. What I really liked was being able to see and feel the difference in handling when you make changes in the spring selection. Now that I have the"BK" I wanted to try the REV3. I can fax you the set up sheet for the Rev3. and also a picture of the old school front end (from an old associated manual. I don't have the technology to E mail it. But if you Give me the area code and a fax # Ican send it to you. I am going to Shoogoo the servo in, for a start. Get the small Kimbrough servo saver. The one that was posted on the forum looks like the rite one. I have been racing 1/12 for years and have never stripped any servo gears (But have broken many servo savers.) The single REV3 sheet I have tells you how to align the servo properly.

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Old 05-26-2003, 10:44 AM   #3036
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Old 05-26-2003, 10:50 AM   #3037
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Old 05-26-2003, 11:39 AM   #3038
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Default retro front end it is!

Ok, now I know what car I'm going to get. I'm going to get the Carpet Knife with the retro front end. I may download or buy a manual for the L3 too if I have any trouble. I'll buy a tweak spring set, and a center shock spring set. Mabey a front spring set also. A foam and plastic bumper. Some extra parts for the retro front end. What pinion gear size should I get for the car? I race on a smaller sized indoor carpet track, any ideas? Are all the Airtronics main servo gears the same size? So any servo saver that says "airtronics" should work on it? What's Sheldon's hobbies site? I wasn't able to find it, but mabey my internet was just all screwy when I tried . I can't wait to order the car now . One more thing, in the pic's of the CK on the CRC site it shows the CK with a servo saver, do you still have to buy a servo saver seperatly? Does the car actually not include the saver and it just show it in the pic's?
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Old 05-26-2003, 04:14 PM   #3039
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I am fairly new to 12th scale. I have been racing off road and touring cars since 89. My problem is this. (12l3) when I turn right and am pushing the car: on or off power, my car just does a 180. I have the tires cut to 1.8 front and 1.9 rear. It is tweaked perfectly (quarters on the front tires and knifing the car). It does it an all surfaces with every set of tires I have tried. I have tried running the diff tighter or looser and that makes no difference. I have tried different t-plates, moving my electronics around, and even preloading my t-plate. I am concinced that it has somrthing to do with the diff or the rear pod. So I am calling on the gurus of this thread for help.
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Old 05-26-2003, 04:44 PM   #3040
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1) Check your tweak on a twaek station, to make sure your mark isnt off
2) Shim the axle, make sure the tires are equidistant from the centre of the car
3) Make sure there is no binding anywhere
4) Check the bottom of the chassis for black marks/scrapes, that tells you the car is dragging
5) Check your front springs, make sure they arent shot. If one of them is, it could be making the car bottom out when you turn one way
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Old 05-26-2003, 05:38 PM   #3041
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I havent considered the axle being off to one side. I will have to take a closer look at that. There is no binding and no dragging, but I was thinking that maybe the wires going to the motor might be interfering. I am running 14guage wire and it looks like it is hitting the body close to the motor. maybe the wire is too stiff or is preloading the pod. What do you think? Have you ever experienced what I am going through? I have seen some racers adjusting their diffs right before a race and when it is not right, the car goes to the right when they stab the gas. Mine would have to be on the far extreme if all I needed was a diff adjustment. When you car is working well and you are pushing hard in the infield, do all pan cars favor the right by design(the diff being on the right side) or is my car just wacked out?Thank you very much for taking the time to help, Art
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Old 05-26-2003, 05:50 PM   #3042
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I forgot to mention, I ran .018, .020, and .022 front springs that were nip on the same track in the same weekend trying to find the setup/problem. It made no difference. I pieced a car together out of spare parts from friends a few months before I bought this one and I kicked butt with it the first time ever running 12th scale. The only difference between the old car built out of spares and the new car I am working with(besides the old delaminating chassis) was the rear axle. The axle on the first car was a trc superdiff. It isnt made aymore and is a two bolt hub.
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Old 05-26-2003, 06:00 PM   #3043
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Default My Guess

I think you will find a bearing in the diff or axle bad. I put em on a pencil and turn the bearing to feel how smoth it is. Just slide it on the sharpened end till it grabs the inner race and give it a spin.

MY Opinion only


No it does not include the servo saver.

Some where on the site I think you go to "Home" then CRC car kits and you will see a nice pic of the knife. Right click and pick set as background. Then You can drool over it in life size all day.

I use 23 to 30 tooth pinions 64 pitch. Start low with big tires and a stock motor. I race with a rollout of around 41mm.

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Old 05-26-2003, 06:06 PM   #3044
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Does the chassis roll to one side when you push it?

Are the motor screws cinched in really tight?

Thats about all I can think of. You might be onto something with the wire. You could try some 16 or even 18 guage wire. I read that Calandra, when he was running in Masters Stock at Cleveland, ran 18 guage, and was very competitive.
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Old 05-26-2003, 06:07 PM   #3045
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Oh, one more thing, try rotating the tires, and see if the problem persists. It could be one is softer than the other, or something wierd like that.
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