Thread: Electrathon - A Different Kind of "Hotrod"

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Looks like a productive three weeks! Hope it sees a lot of time in the winner's circle.

Cool looks like you have a sponsor tag! Always enjoy this thread. Meant to ask before if you've experimented with different tire treads and tire diameters? I know there is a huge difference in resistance between my mountain bike tires(nobbies needing 50 psi) vs. a road bike tire on the same mountain bike.

Yes, Steve, I (and others) have tried different tires over the last 11 years that I've been doing this. We have played with tread patterns, compounds, and air pressure. I found out at my very first race that knobby tires aren't meant for asphalt; we had one on the car because we needed a tire the day before our first race and it was all that was available in town. It lasted about 40 minutes until it shredded. I tried some Avon (OK) and a couple of different style Kenda tires (the Kenda Kontact was OK). Finally, a fellow competitor steered me toward Maxxis Hookworm tires and I've been using them ever since. They are a mid-priced tire ($15 - $22 depending on vendor) that can be inflated up to 110 PSI. I've tried a couple of others since including a different Maxxis tire (Maxxis Miracle), but nothing has held up like the Maxxis Hookworm. They are a durable compound with a fairly thick tread area and a tread pattern that puts a lot of rubber on the ground, almost like a "cheater slick" for a car. I usually run them at 70 PSI, but will adjust up or down sometimes depending on track surface and configuration.

Well, the new car finally made its debut this past Saturday (12-7-13) at Middleton High School in Tampa. There is good news, bad news, and some really bad news. As soon as I unloaded it, the car was swarmed by onlookers and fellow participants. I answered lots of questions and demonstrated the tilt-away steering column several times. In the first race everything was going well. I took it easy for the first 15 minutes, running in the back of the pack, but staying on the lead lap and just getting used to the car's handling and "feel". I increased the pace then and started picking off other cars (good news). I made it up to 2nd place and was closing on the leader with 12 minutes to go when the handling suddenly went away on the right-hand turns - the left front tire was slowly going down (bad news).

Between races I changed the left front tire and went through the usual routine of checking spokes, chain, etc. When the 2nd race started everything seemed good again. The car was performing as expected and the handling was restored. Then, on the 3rd or 4th lap, as I was entering the hairpin turn just before the start/finish line, the steering broke. The car went straight from that point and hit a concrete parking bumper (really bad news). When a car with 2 inches of ground clearance hits a solid barrier that is 6 inches tall the car becomes airborne. I barely missed the announcer and his sound system; I landed between his equipment and the trailer he uses to haul it!

I got a bruised left knee and a severely sprained right ankle, but no broken bones. I'll heal. The car didn't fare as well as I did; it will require surgery to its nose before it runs again. Below are before and after pictures... Crashing sucks!

Jim,did the guy that got Lance's,Rex an my car ever race it at all? ,if not ya should buy it from him,you know full tech support is only a call away,and the alum roll for it's aero body is still in my garage.

Tough luck Jim!!!! Hope you and the car both get healed up quickly!!!!

. . . and the really really good news is that no-one died . . . and no-one was hospitalised with severe injuries . . .

You are so right, Johnboy. If the steering had let go exiting that turn instead of entering, I would have hit a half-dozen folks that were standing at the edge of the track. Probably wouldn't have killed anyone, but there would have been some broken legs and serious lacerations.

I removed the damaged body panels and cut the front tubing off the car yesterday. That allowed me to shoot this picture showing why I lost steering. The eye bolt (blue arrow) is supposed to be between the brackets (red arrow) and there should be a 3/8 inch diameter bolt holding it all together. Problem is, during final assembly, the car builder (me) was supposed to replace the finger-tight standard nut with a wrench-tightened self-locking nut. Obviously, it was overlooked and the nut and bolt eventually worked their way out. I guess we all know what will get checked frequently for tightness in the future...

Hi Bat. Rodney still has the car. I don't know why, but he has not run it yet. Last year after Christmas he bought one of my Silver Bullet rolling chassis and finished it "his way". He ran it for the first time last Saturday and won with it.

Rotten luck on the crash, Jim, and particularly humbling when you realize that it was something that was supposed to have done, but overlooked. A tough lesson for sure, but one that won't soon be forgotten for sure as you say. At least you know that your engineering was sound, it wasn't anything in the design/fabrication that failed, and no one was hurt but for your bumps, bruises and sprains. And think of the show you put on!! Did anyone get video footage of the flight??

Nope, no video has surfaced yet. If there was I would like to see it, too. I would especially like to see the look on the announcer's face. That had to be very close to a "brown shorts" episode for him; it was pretty close for me!

Well, about a week ago I finally tore into repairing the damage caused by my little mishap. When I put the car up on my frame jig I discovered more damage than was first apparent. The bottom left frame tube was bent up slightly right under the seat area. The right end of the front axle was pushed back about 1.5 inches and up about 3/8 inch which also increased the negative camber by about 3 extra degrees.

I straightened the lower frame rail first by removing the left side body panel and using a piece of heavy angle iron and a series of c-clamps. After that, I clamped the car down to the frame jig and used ratchet straps to pull the front axle back forward. To pull the axle end down and regain the proper 7 degrees of negative camber, I used a bar-clamp to apply tension and then rapped the top of the kingpin with a dead-blow hammer; three applications got it right. With everything straightened, I next built a complete new nose for the car. I made this one 2.5 inches longer to improve driver comfort. One last thing I did for driver comfort (that had nothing to do with my crash) was widen the front hoop of the roll cage 2 inches.

Yesterday (Saturday, Jan 11) my son, Jim Jr, and I went racing and had a great day! I took my newly repaired #94 car and my son drove his faithful black #13. I won the first race of the day over Jim Jr. by one lap and two laps over Rodney Schreck in 3rd place. In the second race, our finishing order was reversed (Rodney, Jim Jr, me), but we were all on the same lap. When all the laps were totaled up for the day I won, Jim Jr. was 2nd and Rodney was 3rd. If I'm gloating a little here it's because I also built Rodney's car, so that means Robinson cars made a clean sweep!

Interestingly, my ammeter was not working all day (Electrathon racers normally live or die by our ammeters), so I was driving by "feel" and sound in both races...

Congrats Jim, Post some pics of the new and improved 94 car.

Originally Posted by J. Robinson

I guess we all know what will get checked frequently for tightness in the future...

Clevis pin with a flat washer and a cotter pin through it. Bulletproof.


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Steve - The only discernable difference in appearance is the number on the nose is smaller. I'm hoping some of the folks in attendance yesterday will post some photos of it in action on the Electrathon page. If they do, I'll pirate a pic or two and repost them here.

Tech - That's an excellent idea I hadn't thought of. The local ACE Hardware has them in many different sizes. I look right at them when I'm getting hitch clips for the spindle nuts and it never occurred to me to use them for this. DUH! Thanks for the suggestion!