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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 06-11-2003, 11:02 PM   #3136
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David Root: I just built one of those discharger cut-off devices. I think that the Radioshack relay is not the way to go. Even though it is rated to release at 3.5v, it actually is releasing at 6.5v, and thats wired without a resistor. I suspect that the quality of this relay leaves alittle to be desired. I'm going to try one that is specific to a car application. Does your Bosch relay have a part or model number on it ? LC
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Old 06-12-2003, 02:59 AM   #3137
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Default Yup Graphitedust

Napa AR272 Rated at 30 amps.

I also think a Ford fuel pump or EEC relay will do the thrick. You could try a chevy fuel pump relay or an old dodge ASD relay. I never tried mine on 4 cells because I use my 16 X 5. 10 bulbs is not enough for 20 amps on 4 cells.


I have heard of guys putting cardboard (business card) under one side to adjust camber. They also make CASTER shimms.

I just put a straight edge over the top of my front tires. If the camber is off, you will see it right away by the way the tire wears.

David Root
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Old 06-12-2003, 03:14 AM   #3138
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Default Re: Finsey

Originally posted by David Root
OK, I would make a wire from your + side of the speed controller where it picks up from the + 4 cell battery pack. Run that to a small AAA battery holder - side. Run the + side of the AAA battery holder (red) to a plug that goes into an emty spot in the reciever or the BATT spot. Red wire only. You can use an old servo plug. Hook up your pack as normal, install one AAA battery and DO NOT turn on the switch.

You will have 6 volts to your reciever which supplies 6 volts to your servo. It WILL WORK FASTER. Just look at the specs for your servo, they will give times at 4.8 volts and 6.0 volts.

I had a problem with glitching when My car was far away because there were not enough volts to recieve and process a signal. This happened when I hit the throllte like it was a wire touching the chasis.

All wires only need to be the size of the servo wires.

This would fix a problem like that.

Hope this helps.
David Root
thanks david
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Old 06-12-2003, 04:23 AM   #3139
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12th scale is almost hit or miss. if your car is set up properly it is the easiest thing to drive. The key is getting it set up properly, which is just a matter of being very detailed when you build it. Don't say, "oh that diff is good enough, its just a little gritty" since it will make a difference on the track. however 12th scale (when properly set up) is MUCH easier to drive than a sedan, it goes exactly where you want it to, there isnt any real weigh transpher like there is in sedan so you dont have to worry about setting up and commiting as much.

Jimmy-Business cards or i was suggested to use the header cards on parts bags (the little cardboard thing that tells you what the part is), and i think the header cards are thinner, so a header vs. business card is properly just and adjustment (how much camber you want), not a right wrong thing.
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Old 06-12-2003, 05:32 AM   #3140
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Camber: I'm not sure if they are actually still available, but Parma/PSE used to make a great set of caster AND camber shims for the Old school front end. See if you can dig some up at your LHS.

Stormperson: I agree with you to a certain extent, but a properly set-up 12th scaler is not always easier to drive, as Ray pointed out in his post. Sometimes they'll be edgy and feel very light, on other layouts they may push just a bit. The key with 12th scale is making the CAR fast, and then YOU have to drive it, the way IT wants to be driven. 12th scale is easy to drive, but hard to drive FAST. In 12th scale line is king, and the set-up has to be maximized to carry speed on THE line. Then the driver has to keep it on THE line. You can set the car up super comfortably and drive around the middle of the track, and it may feel fast. But when you look at the lap times it's not. Consequently, you may make the car edgy as sin, stay 4mm off every corner, and think "Man that had to be a KILLER run!", then you check the times and it's just as slow as the previous run. It's when you find the perfect balance of Grip and Rolling Resistance, keep the car in the line that carries the most speed, and don't hit anything that you have a great run.

I think it's way easier to push a bad Touring Car around the track at a competitive pace then it is to get a not so good 12th scale through it quickly.
Team CRC, Access Race Place, US Indoor Champs, CD SUPERPRO, RK Designs, Cypress, Founder and lead instructor of the Ian Ruggles Negative Reinforcement Driver Training Program, enroll now.....
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Old 06-12-2003, 06:39 AM   #3141
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Default Camber and Caster

How to quickly set Caster and Camber on "Old Skool" front end.

First buy a AE or PArma Shim kit and start with the 2-degree caster shims for a Rev.3

This may be a bit difficult to explain, but:

Step 1

I take my rear axle off my car and set the car on my set-up board. I measure caster by lining up my camber guage on the kingpin and take my measurements. Its an eyeball measurement!! Shim on the front or back of blocks to adjust catser. I like between 2 and 3 degrees.

Step 2

I then measure from the set-up board to my stub axle and make sure both sides are Exactly the same height from the set-up board. If not-I shim it up.

I use any thickness paper product it takes!!! In my car right now are header card, business card and two thickness' of plain paper!!!

Step 3

Last-I put the rear axle back in, battery and all the wheels back on (Use a fresh set of trued tires!!) and measure the camber with the camber guage. Shim it up or down, but realize you may now have changed your caster and stub axle heights a little so go back to step one and check.

At a race where thers no time to do all of this-I WILL change my camber settings and not remeasure the caster-but I will check stub axle height. I am just VERY careful to add shims in such a way as to not have a big affect on caster.

The biggest thing is to think a step ahead the whole time!! IN other words-lets say you need to add camber on one side , but the stub axles too high comared to the other side already......hhhmmmmm-WHat to do? Yu gotta work out your options with the shims!!!

Like I said-A 12th scale is a scalpel. Its not like a sedan which, as Cypress said can be driven and forced around if need be.

Hope this makes sense!!

Last edited by rayhuang; 06-12-2003 at 06:47 AM.
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Old 06-12-2003, 07:49 AM   #3142
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Sedans are like a sedgehammer?? You have ever driven my Losi....LOL

However IMHO, 1/12th scales are the best way to train yourself for other classes.

CMW and Ray are correct a 1/12th is like a scalpel...... precision equiptment, and driving one puts you at the peak of your skills, however etting one up teaches you the attention to detail that once applied to other forms of racing really helps make sure you can really have a fast, more bulletproof car......

I even take my 1/12th with me to tracks that most likely won't have a 1/12th class...... First of if enough 1/12th guys show up I can race it, but the main reason is.....

I begin settng up my sedan and getting it to feel like I like it. Next I put it back on the bench and never place it o the track agian unless it's to race, or I broke something and I need to reevaluate the handling..... I then do all my practicing with my 1/12th!!! So I can better learn the coarse, and also I can peak my skillz before the actual races..... Too bad I just figured this works really well for me last weekend!!!LOL

Why does this work..... it's all on the principals of racing a 1/12th. If you wanna be fast in 4 cell 1/12th you've gotta carry alot of cornerspeed, you've also gotta run a much tighter line than you would with a sedan. Also if you maintain your corner speed a 1/12th will be much faster than a sedan allowing you to keep your motor much closer to peak RPM around the coarse...... I have a little story, but I will wait to post it later after I finish the yard and get a bath......
G's RC Raceway- Best off-road track on the east coast...period!!!

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Old 06-12-2003, 07:53 AM   #3143
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Thanks for all the reply. So do you usually get coning problems with an unshimmed oldskool front end? I am thinking of trying out the oldskool on my 12l3. How would it change my steering response with the same spring used?
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Old 06-12-2003, 08:56 AM   #3144
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i havent spent much time finding a settup i just make sure everything on the car is perfect. i rebuild the diff and and clean and lube the damper every race and completely take apart the car between each fortnight racing. i find that no matter how the track is aslong as my diff is good the car handles well.
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Old 06-12-2003, 03:55 PM   #3145
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I was looking at pics of the old school front end on the Speed Merchent site and I couldn't find where you put your camber shims in to adjust the camber. I didn't know that the old style front end didn't have easily adjustable camber and stuff, that makes me kinda bummed. Mabey I'll end up buying a new style front end in the future if I really start to hate adjusting camber. Part of the reason I think I might buy a new style front end is because I don't understand how to adjust the camber, but I think I understand how to adjust the caster. I know you add shims under the front suspension mounts, well I think thats where they go........

Here's what I have so far for measuring camber: get a fresh set of trued tires (front and rear, or just front?) than add shims somewhere to adjust camber. Than run a few laps and see how much your tires coned by placing a straight edge on top. Than true the tires again and check again? Is this right? Im guessing with that method it could take a while, I hope that you don't have to change camber or caster for every run track.

How often do you guys true your tires? Do you get rear tire coning problems too? Do you guys always put 100% sauce on your rear tires? How much do you usually put on your fronts? Also, do you have to put sauce on your tires every run like with rubber tires, or since the foam soaks up the sauce do you only have to do it every other run or something? Thanks for the help, also any other help with adjusting camber and caster on the old style front end would be very appreciated.
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Old 06-12-2003, 04:24 PM   #3146
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I normally like a car with ALOT of steering, so i love 12th scale, since i normally run with alot of it (its hard to keep it straight on the straight, and its not because i am running bad or broken equiptment). However, you do have to be very smooth and you can't jam the car into the turn like a sedan, however line is just as important to go fast, although when a 12th scale is slightly off its more noticable than with a sedan, however when anything on carpet is off, its pretty evident when driving it.

racerdx- you place the shims inbetween the chassis and the bottom of the arm, you cant tell from the pictures, however if you have one in your hand it makes sense.

also the dynamic strut (ae new style) front end is alot harder to get right. last time i built one it took hours to get semi-good. in stock form it binds alot, and there are alot of fit problems with it. so you will end up having problems anyway...
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Old 06-12-2003, 04:41 PM   #3147
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I don't think I'll get a dynamic strut front end now that I've thought about it more. I'll just figure out how to adjust the old style front end. Any answers to some more of my questions would be very appreciated again! thanks
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Old 06-12-2003, 04:43 PM   #3148
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Caster, Chamber, and ride height are all adjusted by placing shims underthe suspension arms.

You don't need trued tires to measure chamber all you need is an RPM chamber guage. Also you won't be able to check for coned tires with a straight edge, you need to use some type of accurate measuring device (most use a set of calipers)....

To get proper chamber you however do need to start with true tires.......

It was already postd within the last few days but here agian is how to figure proper chamber for the best tire wear......

1. Start the car set with proper ride height and caster, everytime you change caster you need to recheck/readjust chamber.....

2. Take a piece of chalk and make a mark across the tread width of the front tires every 1/3-1/4 way around the tire.

3. Make 2 laps around the track at race speed triing to follow the line you will be using in racing condition. ( much slower or too far of the driving line will give you improper readings)

4. Check your marks, the outer edge should be worn away and the inner edge will be visible.

5. Use a small piece of anything of small thickness as a shim (header cards, pieces of paper, buisness card... different thicknesses adjust chamber more of less) Cut it into a 3mm strip.

6. Place the "shim" under the suspension arm on the outside of the screws.....

7. Remark the tires and repeat until the car comes off the track with the mark worn off of the entire tread width, you may have to use thinner shims or thicker shims to get even tire wear......

8. Use an RPM chamber guage to check and record the setting, also record caster set-up, track comditions, and lay-out information (alot of sweepers, mostly tight, 2 right-handsweepers w/ severasl tight left handers....ect.) this way if the lay-out is changed and you come accross the same type of lay-out in the future you know where to set the chamber to avoid all of this testing.

Remember as I stated earlier if you changer caster you may also need to readjust chamber for even tire wear.....

Also you may need different chamber angles for each side if you do come across a lay-out that has more sweepers in 1 direction than the other.......
G's RC Raceway- Best off-road track on the east coast...period!!!

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Old 06-12-2003, 04:47 PM   #3149
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I'm waiting on the V-Force front end!!!!!!!

may have to try a speedmerchant if it comes with it on there!!!

BTW: Ray what i the asking price on the REV. 3
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Old 06-12-2003, 05:33 PM   #3150
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Guys - be careful with the shims. The Associated shims are 0 and 2 degrees for castor. The Parma PSE castor shims are twice the degree marked on them. That means a 2 degree shim is actually 4 degrees. I think the PSE camber shims have the same discrepancy.

So Mr. Impact - what track do you run your 1/12 scale car for practice?
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