Gearing to Win
and the Importance of Making Notes

Set your Gears to Win

   Just because you have the latest model, the best available batteries, the most powerful electric motor or nitro engine, doesn't mean you will go out and win everything in sight. The fastest car on the track is rarely the one that wins, it's the one that can accelerate out of corners under control, and remains consistent and efficient from the start to the end of a race.

How things used to be (Once upon a time ...)

   In days gone bye, all you had to consider was the number of mili amp hours (Mah) in your battery, and the current draw of your high powered motor. Gearing for a five minute race was a balancing act. But with the development of the new high capacity batteries, brushless motors and smart ESC, all that changed. Now, gearing is more of a matter of what suits your driving style and how quick your reflexes are on the sticks, the trigger and steer wheel of your transmitter. So, where do you start?

Local Club Racing

   At your local club track, you quickly find the right combination and set-up for your car by talking to the more experienced members. After a while, as your knowledge grows, tweaking a few things here and there can give you that small edge to keep you competitive. So, it follows that on tracks you don't know, you should talk to the locals there, who may be racing a similar model to your own, and adjust your set-up to suit.

Gear Setting Pitfalls

   Gearing correctly for any given track is absolutely crucial if your car is to be competitive.

   Too high a gearing may get you in front at the start of a race, but as your motor begins to overheat and lose efficiency, that initial advantage will soon be lost.

   Too low a gearing, and although it may get you past your opposition accelerating out of the corners, you will loose that place again on the fast straights. Gearing low will always get you to the end of the race, but it will hardly ever get you on the winner's rostrum.

How to find the Right Gear Setting

   On tracks you don't know, initially it's always best to err on the side of low gearing. For your first practice laps on a new track, choose a motor that has a reasonable current draw, and with a fully charged battery, try a race length run, learn the corners - what line to enter and exit, where you can accelerate to overtake, and how fast you need to be on the straights to keep up (not overtake) the opposition. After your practice race, check the remaining capacity in your batteries and the temperature of your motor, (keep records of each motor and discover at what temperature a specific motor loses efficiency - all this helps when selecting the right gearing.)

Use what you Learn

   Armed with this knowledge, you can then consider how to alter your gearing. Use a ratio chart.

   If the motor is cool (in comparison) and your battery has ample remaining charge, try a larger pinion - perhaps one or two teeth more. Don't overdo it.

   An overly hot motor, and low remaining capacity battery speaks for itself. The race timed practice run should have given you an insight to this problem. Obviously, in this instance you must use a smaller, less teeth pinion, or start again with a milder, less powerful motor.

   If the motor is hot, but not too hot, the battery has ample remaining charge, and you did not notice any drop in efficiency towards the end of your practice run, then you are close to the optimum set up for that particular motor.

After Each Competitive Race

   Depending on how competitive that set-up is, you can stick with it, maybe tweak a tooth up or down, or if your car isn't keeping up with the rest, using the information you have gained, repeat the process with a different motor to get you where you want to be.

Gears Types for RC Models

Metric Module and Diametral Pitch

   In RC there are a number of different gear teeth sizes we tend to use, based on two systems. Imperial and metric.

   The imperial system has sizes 24dp, 32dp, 48dp and 64dp. DP stands for Diametral Pitch and the number refers to the number of teeth per inch.

   The metric system has sizes 0.4m, 0.5m, 0.6m, 0.7m, 0.8m and 1m. M stands for Module and is the ratio of the reference diameter of the gear divided by the number of teeth.

Why are there so many different sizes?

   The different sizes are used basically for strength. 32dp gear teeth are larger than 64dp gear teeth, therefore the 32dp gears are by design stronger and for this reason are more commonly used on a number of entry level buggys, to help them withstand the knocks and crashes by drivers new to RC and nitro models because of the higher torque levels involved. Also, the bigger the scale of the model, the stronger the teeth need to be.

What would 64dp Gears be used for?

   64dp and its metric equivalents are generally the choice of 1:10 electric on-road racers, because of its higher range of ratio options and smoother action in comparison to other sizes. On-road models are not as hard on the gears as off-road, so the weaker, small tooth size is not a problem.

What would 48dp Gears be used for?

   48dp and its metric equivalents tend to be preferred by 1:10 off-road racers, mainly because of their strength in comparison to the 64dp and smoother operation than 32dp. Off-road models need gears that can handle all the knocks and bangs, as well as heavy landings off high jumps.

How to set Backlash between Gear Teeth

   Setting your gears is the most important part of looking after your gears.

   Backlash is basically the gap between the teeth in mesh. The perfect gear setting must have a small amount of backlash. To achieve the best setting use a very thin sheet of plastic between the pinion and spur gear teeth as you press them into mesh. After tightening the motor mount screws, use your fingers to spin the spur gear and roll out the plastic sheet.

   If the setting is correct, there will be a small amount of movement (backlash) between the gear teeth before they catch. If the mesh is too deep, there will be no movement between the teeth, this will create friction and if you run them like this, they will grind together, wear and break. If the mesh is not deep enough and only the tips of the teeth are touching, the excessive backlash will soon damage and strip the tops off the teeth rendering the gears useless.

The Importance of Keeping Notes

   If all you will ever do is go racing at your local track every week, then this article is not for you. However, if you ever look towards travelling around to different tracks around the country, or even the world, the value of keeping notes is all too obvious.

Regional and National Competition

   Every time I raced in a regional or national competition meeting, I would make detailed notes, aided by a little local knowledge initially and later fine tuned to suit my own driving style.

   My experience now means there are few, if any outdoor tarmac tracks within a 300 mile radius I haven been to, and my notes on motor, gearing, camber angles, shock settings, tire choice and what inserts work best for that particular track, amongst others, allow me to save valuable time on the finer points of car setup, that can be done in the warmth of my own home on the kitchen table days before the meeting, instead of the often crippling heat, or the arduous conditions inside a wind blown tent.

Download Setup Charts

   There are lots of methods for making notes on setup. The easiest perhaps is to download the blank pages often supplied by your cars manufacturer with a line drawing of your car and spaces for you to fill in as to the setting you prefer. Great if each time you go to a particular track the conditions are always constant. Notes made on a cold windy day will be little use on a hot sunny days racing on the same track.

   Manufacturers setup pages for their top drivers can also be useful as a starting point, but you should never take that setup as being the best there could ever be.

Don't forget to Note the Weather

   So, the first note you should make is of the weather conditions. The wind and its direction isn't really what I am talking about, although it can have an effect on your cars handling, it is not something you can change your setup to handle. Track temperature and humidity are the main things to note. Not the average for the day, but for each round of racing. And note what tires you used, and how the car handled in each race. Detail everything that might be useful in the future, no matter how trivial.

Motor and Gear Settings

   Note the motor used, and the gearing. Check the temperature of the motor after the race, how much charge is left in the batteries. You may have won the race, but there is always room for improvement - your competitors will be doing just that.

   Every bit of information you compile will be useful for the next time you visit that particular venue. Weather forecasts these days are far more accurate than they used to be, so the adage "fore warned is fore armed" fits the bill. Simply search through your notes and find a day you raced with similar conditions to those forecast, and set up your car to suit. But don't stop there.

Keep Modifying your Notes

   The conditions may be the same as they were when you made your notes, but that doesn't mean you can't improve your setup. Your practice laps will soon prove if your previous setup was correct, or give you a basis for more fine tuning.

   If you want to be the best, you have to work at it. Success doesn't come easy. You can be the best driver around, but if your setup isn't perfect you will never step up onto the winners rostrum. My motto - if you never try anything, you never do anything. And if you never do anything wrong, you aren't trying hard enough.

   At present, the RC Model Manufacturers, Brands and Distributors covered by us are: ABC Hobby, Academy, Acme Racing, Agama Racing, Amewi, Ansmann Racing, ARRMA, Team Associated, Atomic RC, Axial, AYK, Bolink, BSD Racing, Capricorn, Carisma, Carson, Caster Racing, Cen, Corally, Custom Works, Durango, Duratrax, ECX - Electrix, Exceed RC, FG Modellsport, FS-Racing, FTX, Fujimi, Gmade, GS-Racing, Harm, HBX, Helion, Heng Long, Himoto Racing, Hirobo, Hitari, Hobao, Hong-Nor, Hot Bodies, HPI, HSP, Intech, Integy, Jamara, JQ Products, Kawada, Kyosho, Losi, LRP, Maisto, Mardave, Marui, Maverick, MCD Racing, Megatech, Mugen, New Bright, Nichimo, Nikko, Nkok, Ofna, Pro-Pulse, Protech, PTI, RC4WD, Redcat Racing, RJ-Speed, Robitronic, Schumacher, Seben, Serpent, Smartech, Sportwerks, Step-Up, Tamiya, Team-C Racing, Team Magic, Thunder Tiger, Tomy, Top Racing, Traxxas, Trinity, Tyco, Vaterra RC, Venom, VRX Racing, WLToys, X-Factory, Xmods, Xpress, Xray, XTM, Yankee RC, Yokomo, ZD Racing and Zipzaps.

   This is an ongoing project, with new and "lost in time" RC Models and Brands being added as they are found and although most of those listed above have been covered in relative detail, some are still being researched and will be completed in the near future.