Stealth Mode: The Quiet Simplicity of The Idler Wheel Drive

I was watching a recorded episode of the Worldwide Slot Car Chat earlier this week and listened to an extended conversation regarding the ubiquitous Fly Vipers that not only changed the nature of modern slot cars some 20+ years ago but which seem to reside in almost everyone's slot car garage. Many people have multiple models of this car, since they were very popular and continue to be widely available at very, very affordable prices.

At first glance, this Viper looks like a lot of others.

Strangely enough, I don't own one. But I do own a Viper--a Carrera model that was among some of the first cars I ever purchased. Listening to the owners go on about the shortcomings of the Fly version--with its front-motor position, "drive shaft" and inevitable handling and tuning issues, I decided to dive into my storage box of cars and retrieve my old Viper and check it out again, as I knew it had very little in common with the Fly cars.

Aesthetically, it is wholly comparable to the Fly cars, with nice detail, sparse but decent-looking decals, and overall--leaving an excellent impression. Flipping it over and looking at the chassis reveals something different, however; when I showed it to the other people in our chat, they were surprised to see what appeared to be a sidewinder setup. They were even more surprised when I showed them a photo of the body removed--revealing an extremely simple idler drive (also known as a "friction" drive) with a rubber contact wheel in place of a pinion gear, contacting directly with the right rear tire to drive the car. You'll also note the two spring mechanisms in front of the motor that helps adjust tension so the drive maintains good contact with the rear tire.

Have you ever seen an idler-drive slot car? Here you go...

With so much discussion of pinions and crown gears, tooth-counts and related tech talk, it was fun to see the reaction to this ultra-simple setup. In truth, this car was always a pleasure to drive...comparatively quick on my old track and best of all--superbly silent. It was almost like racing in stealth mode, with no gear grinding or whining at all. In addition to this one, I also have two other Carrera models with the same setup, a green Jever Porsche 911 GT1 EVO 98 and the 1999 Audi R8R LMP. As I seem to recall, the Porsche was the fastest of the three, with the Audi a close second, probably due to the fact that it may have been a bit heavier.

Both of these cars are nice runners, too. The Porsche is the quickest.

Not really sure why Carrera decided to use this drive in its cars, or why it stopped. It may have provided some relief to mothers, who only had to listen to their children's shrieks of joy while playing--without the added gear noise. Obviously performance would be an issue, but on my old 50 foot track, with a generous amount of curves, these cars were still competitive...and a pleasure to drive.