The Kyosho Optima is one of several classic RC cars that have recently been put back into production. These reboots give you the nostalgia of owning an 80s-era racer, but without the cobwebs or impossible-to-find spare parts. In my previous article, I covered the process of building the Optima into a functional vehicle. This time around, I'll take it out for a spin and see how this baby performs!
Finding New Shoes
My plan was to test the Optima in different driving conditions. I took it to a track designed specifically for off-road cars. I also let it loose at a park in my neighborhood. But before hitting the ground with my new retro racer, I figured that it would be prudent to analyze the tire situation. Having the right tires for specific conditions can make all the difference in how a car performs.
A significant aspect of the Optima's enduring image is its set of 5-spoke "twisted star" wheels wrapped with fat, studded tires. While Kyosho's re-issued rollers definitely resemble the original parts, they are actually quite different. First of all, the wheels are now a 1-piece design. The legacy wheels consisted of inner and outer halves that were screwed together to pinch the tire in place. Going with the 1-piece approach produces lighter, stronger parts, but the tires must be glued to the wheel--not a big deal.
The primary change to the tires is that they are now made of a softer rubber. In fact, the tires are so soft that they require foam inserts to help them hold their shape. Tire inserts are common nowadays, but I don't recall them ever being used when I was an active RC racer in the early 90s. The benefit of soft tires is better traction. One of the fundamental tradeoffs is durability. Simply put, softer tires wear out faster. That's not usually a concern for racers. Traction trumps longevity every time.
Just as off-road RC cars have evolved over the years, so have the tracks they race on. In the 80s and 90s, it was common for off-road tracks to have a layer of relatively loose dirt on the top surface. That's why the Optima's tires (and many others) featured prominent spikes. They could really dig into the fluff and get moving. Modern tracks are typically made of very smooth and hard-packed dirt. Some even use carpet or astroturf. Many racers use tires that look more like drag-racing slicks than traditional studded off-road tires. It was obvious that even with softer rubber, the Optima's prickly paws weren't going to cut it on a modern RC track.
I sought advice from JConcepts, a company that manufactures wheels and tires (and other parts) for RC racers. They mostly deal with the latest and greatest competition-grade machines, but they helped me sort through some options for the 30+-year-old Optima. We had to overcome a couple of challenges before finding workable solutions.
I have a few spare sets of stock wheels for the Optima. I was hoping to find different tires to throw on those wheels and hit the track. Those hopes were squashed because the twisted stars have an outer diameter of 1.7" (43mm). The current standard wheel diameter is 2.2" (56mm). So there are very few contemporary tires that will fit the stock Optima wheels.
The next approach was to equip the Optima with 2.2" wheels. This was no problem for the rear end. The axles have "12mm hex" drive hubs, which are common on modern RC cars. Mono full-width rear wheels will bolt on to the Optima and open up a wide selection of 2.2" tires.
Finding wheels for the front was slightly trickier. That's because most modern wheels have a larger offset than the Optima was designed for. The mounting hub on a twisted star is close to the center of the wheel's width. The mounting hub on a high-offset wheel, however, is very close to the outer edge of its width. This leaves the inner part of the wheel wrapped around the suspension components. There just isn't as much room to work with on the front end thanks to the additional steering mechanisms.
Full-width MONO wheels very nearly fit on the front of the Optima. You could probably make them work by using smaller ball joints on the steering linkages or filing down the existing ball joints just a little. But most modern 4-wheel-drive cars use narrower wheels and tires on the front anyway. So I wanted to try that option before tweaking the car. I found that Mono front wheels fit nicely and provide ample clearance.
I had no idea which tires would work best for my planned driving locations. JConcepts suggested I try Goose Bumps, for front and rear, as well as Dirt Webs for front and rear. I was really surprised to find out that most of the tires are available in several different rubber compounds. They range from "firm" to "mega soft". I didn't have such options during my racing years.
Like the stock tires, the units from JConcepts also require foam inserts, which are included. I did not have any trouble mating the wheels to the tires. The fit is very precise. You might even think the tires hug the wheel so well that you don't need to glue them down. WRONG. Glue is mandatory. I used thin CA, applied with a small disposable pipette.
At the Track
I took the Optima to R & L Hobbies in North Tonawanda, New York (a suburb of Buffalo). The shop features an indoor off-road track where they hold organized races several times a week. In its current layout, the track has a lot of tight turns and huge jumps. It is definitely a fun place to drive.
I wanted to get a baseline reading on traction, so I ran with the stock tires at first. That didn't last long! The car was very difficult to drive on the hard-packed dirt. I had to be super-gentle with steering and throttle to keep the car pointed in the right direction. Switching to the Goose Bumps provided a significant improvement in handling, but the Optima was still a challenge to drive.
Going with the Dirt Webs finally gave me the traction I was looking for. I could drive much more aggressively without the car swapping ends. Finding the right tires for the Optima revealed two things. First, this car is fun to drive. Second, my driving skills could use some work! It had been more than 20 years since I last drove on a track and I was all over the place. I was quickly reminded that precise and consistent driving are much more important for winning races than having the fastest car.
The 20-turn brushed motor from Kyosho's starter pack actually hauls the Optima around very nicely. Honestly, I need more driving practice before any additional horsepower would be useful. I may upgrade to a hotter brushed motor, or even a brushless setup at some point. But the car is plenty fast for now.
I mentioned in the last article that I glued the battery straps to the chassis with GOOP. I made this modification following my experience at the track. Every time I loosened the straps to remove a battery, one or both straps would fall to the floor. It was frustrating then, but no longer a problem.
The huge double-jumps at R & L can really make the Optima soar. Executed properly, the car will sail off of the first jump and then land smoothly on the backside of the second. It's a thing of beauty. The doubles are also unforgiving. If you hit the first jump too slowly or misaligned, it's going to get ugly! The best you can hope for is to slap into the face of the second jump and continue on. The more likely scenario is a tumbling crash. I had my share of those.
Between botched jumps and driving into the barriers, I repeatedly tested the Optima's durability. Most of my mishaps were of no consequence. On one occasion, however, the bottom ball joint of a shock popped free. Another time, one of the front dogbones came out of the drive cups. Either of those situations would have been a race-ender, but this was only practice. In both cases, I simply snapped the parts back into place and got down to driving. I never actually damaged any components.
The Orion Vortex ESC that I used is equipped with reverse throttle. It came in handy during the countless times that I nosed into the pipes that border the track. I could back out of trouble and get moving forward again. However, reverse is not allowed at most organized races. It can be disabled on this ESC with a jumper.
Overall, I had a great time driving the Optima around the track. It felt good to get reacquainted with the sights, sounds, and smells that are unique to a dirt racetrack. I don't know that I'll ever get back into organized racing. But I will probably grab the Optima for practice sessions from time to time.
At the Park
My neighborhood park has a nice softball field with a clay infield and grass outfield. The infield is well-groomed and has a layer of loose dirt on top, just like the tracks I used to race on. I thought this would be a great place to utilize the Optima's stock tires. I was correct.
The infield surface was dry, causing the car to throw clouds of dirt skyward with every turn. But the spiked tires hooked up well. The Optima would only spin out when I purposely tried to do so with abrupt steering and throttle inputs. I also tried the Goose Bumps and they were even stickier. I'll be revisiting the park after a rain shower to see how things are different with damp dirt.
The tight-twisty indoor track is fun, but the wide-open infield was a whole different kind of fun. Here, I could drive full-tilt, rounding the bases in drifting turns. I could then whip the car into tight donuts until it was lost in a cloud of dust. I never really thought of the Optima as a "basher" RC car, but it can be driven that way. It's tough enough to handle the abuse.
I tried driving in the grass as well. The car would go through it, but it tended to get bogged down in the thick stuff. I think the tires are a bit too small for anything other than very short grass.
After running several batteries back-to-back, the Optima was still in great shape. A little dirty, sure…but mechanically and electronically sound. The motor didn't even get very hot. That's unusual for brushed motors. I probably have some headroom to change the gearing for more speed at the softball field. The stock gears seemed about right at the indoor track.
Reviewing the Optima has been like stepping into a time machine. Everything from building, painting, and driving this car took me back to my younger years. It's been a fun journey. Apparently, many others agree with the appeal of these retro RC machines. Manufacturers continue to offer more and more vintage RC products. In fact, Kyosho just recently announced the re-release of the Optima's roll-cage-equipped cousin, the Javelin. These vehicles may no longer represent the latest racing technology. But they are still tough, adaptable cars that are a lot of fun.
Terry is a freelance writer living in Buffalo, NY. Visit his website at TerryDunn.org and follow him on Twitter and Facebook. You can also hear Terry talk about RC hobbies as one of the hosts of the RC Roundtable podcast.