Dateline 08/16/97

The following was given to me by Chuck Kimbrough, the owner of Kimbrough Products, and are his thoughts on Stock class racing.

This is just a suggestion, after thirty years of my experience with slot and R/C model cars. I don't care what you hear from other manufactures or any one else that just doesn't understand, this is the way it really is.

Model car racing is NOT a spectator sport (it can't compete with full size cars live or on TV), it's a participation hobby.The only way it can be bigger and a more important is to have more participants.

Thousands of people buy competitive R/C racing cars kits every year, but only a few hundred stay with the hobby very long. The reason it doesn't grow is the high drop out rate. If you happen to run into an ex-R/C car racer, ask them why they quit. The answer I hear the most is, "the cars got too fast and it took too much time and money to be competitive".

TOO FAST! can't be you say. Think about it, do we really need to set new track records when we race? Is the idea and FUN of competitive racing to beat the clock? No! the real challenge is beating the other racers in our class.

Did you know many thousands more people play slow pitch soft ball then any other organized form of this stick and ball game?

Thousands more amateur and semi-pro racers drive full size cars like the Legend Cars, Formula Fords / Renault, Vintage and all the other speed regulated sports car categories, then are driving in Formula One, CART, Winston Cup, Bush GN or Outlaw Sprints.

Although they all would love to be a professional driving a Formula One car ect, most of these amateurs don't have the talent to do so, and would probably kill or injure themselves if they tried.

To keep more people in the R/C car hobby we need a class that is slanted toward close wheel to wheel racing at lower speeds and cost. The average hobbyist does not have the reflexes to be in full control at the speeds the present stock motors produce, especially in on-road and oval racing. When the average Joe or Jane gets on the track with one of these rocket motor they are only partially in control, and an accident just waiting to happen. We all know how much better people drive after the first minute or two of a heat, when the hot part of the battery charge wears off and their car slows down.

A stock motor class should be noticeably slower then the modified class, so people who don't have lightning fast reflexes and a lot of money, have a place to compete. As it is now, there's not much difference in car speed from stock to modified, and they are both expensive.

Why haven't the one design classes where the racers use the same chassis, tires, gears, and motor solved this problem? Because frankly, these lower priced cars don't handle as well as an open design car. In other words, high speed is the problem, and one design cars don't address this, they might even make it worse, because their harder to drive then an open design racing car.

The problem begins when a novice wins a few races and is bumped up to the stock class. All of a sudden they go from being competitive, to being lapped a few times by the front runners. Most of them soon get discouraged and in a short time the hobby is another participant poorer. That's a shame, because these people would really like to continue racing R/C cars, but because they don't have the money, time or talent to be somewhat competitive in the present stock motor class, they hang it up. It's no fun racing if you know there's hardly any chance of you finishing on the same lap as the winner.

To be really competitive, a racers needs a commutator truer (some experts true their motors comm. between every heat at big races). Even the nominal cost of having it trued by someone else can add up. Plus the fact it can only be trued a limited number of times. After it's trued, a Dyno is needed to tune the motor. This can really make R/C car racing an expensive hobby.

It's easy to see the weak part of R/C car electric motors is the commutator. The reason the motor slows down is that the comm. distorts or goes out of round from the heat of high amperage loads. This happens every time the motor accelerates from a dead stop or slow speed. These high amp. loads are magnified many times when the timing is advanced, the more the advance the higher the amp. loads. That's what burns up the comms. The proof is the limited number of fast runs you get with 36 degree stock motors.

What's needed is to reduce the timing, but not just by half, that isn't sufficient. If the motors had zero degree timing, the amp. load would be reduced enough that stock comms. would last 20 times longer then they do now.

The Hot Shoe stock racers will tell you, "zero degree motors will be slow and have to be geared really high to get any speed, so will still pull a lot of amps.". Trust me, you can't gear a zero degree motor anywhere near high enough to pull the amps a 24 degree motor pulls off the starting line now. The Hot Shoe stock racers I am referring to, are the guys that are good enough drivers to control a hot modified car, but race in stock because it's easier for them to win. You notice I didn't say cheaper, because it isn't.

There are many cost advantages with a zero degree timed motor.

1. The bushings and brushes last longer in a slower RPM motor.
2. They can be used in a left OR right side drive oval or on-road car.
3. A slower motor with more torque uses a larger more efficient pinion gear.
4. Tire and general wear and tear on the car is less.
5. Zero degree motors don't suck near as much juice out of batteries, so expensive matched packs won't be needed.

A zero degree timed motor runs the same speed in ether direction of rotation, so the timing can be checked or teched easily (Something that can't be done with the present motors) by using an amp meter, or your ear by simply running the motor in both directions, and comparing the amps load or pitch of sound.

On a zero degree motor the timing can be one or two degrees off and it makes very little difference in speed, while on a 24 or 36 degree motor 2 degrees makes a big difference. So the motors will be more closely matched. Timed brushes are outlawed in stock, but even if a cheater used them, they wouldn't gain enough to notice. Naturally a comm-lock, and notched or pined end bell to can connection will be required.

What do we do with the existing motors? No problem, just create a super-stock class for the Hot Shoes. To make this hobby grow we need three motor classes.

How will these zero timed motors get built? If rules are made for this class by ROAR and NORRCA, manufactures will start making them just like they did the last time the stock motor rules were changed.

If zero degree stock class motor rules are made, a number of other specifications need to be nailed down with close tolerances, such as, thickness and number of armature lamentations, shape, and length of armature (no gaps or slots). Thickness of metal in the can, size and shape of holes in O.D. of can, and length of the bushings. Size and shape of brushes. Size and diameter of commutator. Or anything else that might effect their performance.
The reason for this, so stock class racers won't have to keep buying new motors every time a manufacture finds another loophole in the motor rules. The Mabuchi motor would not be the answer for this class because it's to easy to tinker with.

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... continued from Post #1

If you like the idea of slower more affordable racing with zero timed motors, tell ROAR, NORRCA, or their representatives about it. Most of the input they get is from the Hot Shoes and Expert racers. Low budget club racers need to make some noise about what they would like, or nothing is going to change, and the R/C Car Racing Hobby is not going to grow. As a matter of fact, the hobby has gotten smaller at about the same pace as the stock class motors have become faster.

Most club racers say "there is no reason to join ROAR or NORRCA because these organizations don't concern them". I understand where their coming from, because these organizations and their rules are set up mainly for the highly dedicated and factory sponsored racers who travel all over to race. They don't offer any programs in the way of slower classes for beginners or weekly club/commercial track racers.

When I first joined ROAR in the early nineteen seventies the rule book stated on the first page, "ROAR was established to promote radio control model car racing". I'm sure the founders meant this for all R/C car racing, not just regional and national championships. This statement disappeared from the rules many years ago, and most of the small time club racers have disappeared from ROAR, because it appears ROAR has no programs for them.

What club racers fail to recognize is the rules made by these governing bodies (ESPECIALLY MOTOR RULES) affect all of them. As far as I know the membership of these organization is mainly big time racers, who dictate what they want to the rule making committees. If club racers would join up and let the rule makers know how they feel, maybe rules would be made directed towards them. So instead of just belly aching about the high cost of racing to your buddies, join a rule making group. Remember the squeaky wheels get the grease.

TRACK and HOBBY STORE OWNERS, especially those of you who have tried to promote slower classes by other methods (like fewer batteries, specified gear ratios, etc.), join ROAR or NORRCA and encourage or require your racer customers to also. Then all of you make some noise about a more economical racing class. There's no doubt a new slower motor class would increase business and keep more racers in the R/C car hobby.

ROAR and NORRCA combined have nowhere near as many members or as much money to work with as the Academy of Model Aeronautics, because the AMA has classes and engine sizes for almost everyone, not just the hot shots. They even have a control line class called SLOW combat.

I have proposed ideas similar to these in the past with little or no results, but now that we have a lot of average racers on the internet, maybe we can mount a campaign so rules makers will respond to the little guys not just the Pro. racers.

Chuck Kimbrough

hi chuck,
i like the idea of the zero degree timed motors but with the new technology of brushless motors what do u think about those?

Brushless motors sound good untill you get into the programming of the speed controller, which makes a huge difference with brushless motors.

I like the idea of having a stock motor with 20 degrees, but how will the manufactures react to this? This will require all motor companies to produce new motors, which mean they have to spend money to get the best working motors within the rules.

At my local track, they only race stock, leaving the new people to run with the factory sponsored drivers. It would be nice to see a "factory" 24 degree stock and 0 degree stock class come out.

hi!
here in Spain, last year, we create a kind of stock racing, but instead of 19T 24º fixed timming, 17T 5º fixed timing
the resoults were very good, i only espent 2 motors in all year and only 12wheels (3 cars), i saved a lot of money... with that timming the motor does not suffer any effort and lasts a lot of time!!

delete.

Good idea Hank.
I never race at the large events because the cost 40-50 bucks just to enter, but you need about 5k in gear just to make the a-main in any class. Yes, every now and then a no-name will pop up and take a win, but for the most part, were out of luck.

I think it would be great to have a minor legue in RC where it isnt all dictated by how big your wallet is. I remember when stock motor racing at my track was the way to go, but as soon as the first motor dyno showed up at the track , all that changed.
Im way too good for sportsman and i dont have the cash to throw down on motor dynos, brushes, back up motors, arms, etc, etc, etc.

I recently started a Tamiya mini cooper class at my track that only allows the silver can mach. motor...closed endbell. I have more fun in that class than my 1/10th 4wd touring class. It gives me time to relax and just enjoy racing with friends. Ive been in the hobby for 8+ years now.
I have talked to my regional director in ROAR. I basicly came away with he is way to busy to introduce anything new. I can only imagine the same holds true for any region. I only hope they fix it before its too late and only cover national and international events. Almost everyone at my track has dropped the ROAR membership. Who wants to pay 45 bucks for a small plastic card that does nothing but show your name. I sure dont.

in your country i think is easier to intruduce a new categorie beacuse you are a lot o f more people than in Spain... that is the main advantage you have, you can make new categories as often as you want (more or less), here, if we are lucky maybe we can run 40 drivers in a National Championship!! that is no people compaired to you... it is a true pity... nut if you stay in a hobbyshop for a day and see houw many people buy a car you will be surprised...a lot of people buy a new and a powerful car but no one wants to race... their argument is: it is to expensive... and my answer is: not in stock racing...

I have 2 responses to this article. The short one is:

Chuck Kimbrough for ROAR President!

The long one is: We tried something similar to this at a small track in central Michigan many years ago. We used another motor builder's clone of the Speedworks Dirt Oval Stock motor, which was actually a 23 turn with 8° of timing. Each racer was only allowed to buy 1 motor per class, and the motors were kept at the track. Also, you were only allowed to cut the comm ONCE in the 6-week series. (This was easy to enforce since only one of us had a comm lathe.) We ran 3 different points series of 6 weeks each, all using the same motors you started with. At the end of 18 weeks of racing, the motors were still running great. In fact, almost everyone had gained 2-3 laps by the 18th week. I think the motors could have lasted a year.

Back when ROAR came out with the 1991 stock rules, they sounded like a great idea (and were, until the designers got too clever). A stock motor in 1990 had up to 44° of timing would last MAYBE 2 weeks if you were extremely careful with your gearing (and probably too slow :D ). The 1991 motors lasted much longer, but then about 93 or so the design wars started, with short stacks, laydown brushes, different pole shapes, etc. Seems like this was also when I started seeing more of the really fast drivers running stock instead of (or in addition to) modified. I agree with Chuck, the only way to create a truly beginner class and get the fast guys out of stock is to make stock class so slow that the really good drivers won't want to run it. And the motor specs MUST close all the loopholes. If a motor design submitted for approval looks the least bit clever or innovative, REJECT IT!

I remember when we raced 1/12 scale in the 80's, the ROAR stock motor was the Igarashi. It was a closed endbell motor. I don't remember the winds or turns but I remember there were 2 versions a white endbell and a blue end bell with the blue being the hotter motor. I got one as a hand out at the Red Lobster Classic and used it for almost a year club racing. My point being that everyone had to run this motor and it made for some close, exciting racing. It was also a very inexpensive motor. The bottom line is we had fun for not big bucks and there was not the hassle in teching the motors.