John’s Blog – RC Dirt Bike at Lompoc Valley Race Track

It has been way too long between moto sessions for me with my rc bike but finally, two weeks ago (September 30th) I was able to make it out to the local rc track! Lompoc Valley Race Track is an offroad r/c track located in the small city of Lompoc, California about 40 minutes north of Santa Barbara. Its a community operated track that primarily runs novice, sc truck and 1/8 buggy racing on the first and third Sundays each month. Volunteers maintain the track almost weekly but only race days the track is watered. Check it out on Facebook and and at www.lompocrcclub.com

The dirt on this track is very fine, almost powder like sand that you would find on a river bottom. Track conditions for the Monday I was there were hardpack, dry, and dusty with some bumps so overall it was pretty slippery. Width of track looked about 10 ft across, but I didn’t measure. Current layout goes counter-clockwise where the start straight includes about a 30 ft double table top section the 1/8 buggies can clear, a sweeper turn (blocked off for repair), a pair of small double jumps between a short 180 turn, and then what I would call a triple step-up jump about 4-5ft tall plus 120 degree left turn combination, followed by one small single jump and back around to start straight. Some parts manageable other parts a bit extreme for rc bikes.

My Ryan Villopoto replica Atomik MM450 has the e-gyro in back wheel. Front tire was old rubber and maybe had 70% tread, while the rear tire had maybe 35% tread left. I had the epa for throttle turned down to 75% on my 4800kv 550 stock vmx450 motor and the thottle curve set to exp -6 or so to smooth out low throttle cornering. I do run a big bore shock in rear thanks to Chris Haertel, and when I hit the jumps squarely and on the gass the suspension worked awesome. Huge jumps the bike would bounce once on impact and just continue on. Amazing compared to stock shock and a must for this bike. Front end was a little high on the big jumps but correctable with some brakes applied mid air. My steering servo wasn’t turning as smoothly as I like so not sure how much of a factor that was. I do have the front brake kit installed but I need to swap out the cable with my thicker 1.2mm replacement cable.

Last time I was out to this track was over a year and a half ago when I ran my bike with a mechanical gyro in February 2012. This day at the track I was able to get three batteries of fun in but each time I had something happen. On the first battery the grub screw for front sprocket came loose (the first time that’s happened in 2 years maybe). On my second battery the rear shock cap was loose and all the oil spilled out, but that was my fault as I accidentally loosened it the previous night trying to adjust the spring. On my third battery my rider’s head and the spur gear cover came off. I brought my tool box so my day was saved. The head and spur cover were found afterwards so no lose there.

Primary goal was to make it one lap around entire track without crashing, no matter how slow I did it. First battery was clearly about me getting exercise walking around the track picking up the bike after hitting every single barrier, or launching off a jump at the wrong angle. It was all about just learning what the heck the bike does when I give it too much throttle, or how much steering it takes to get around a corner, or how important lining my jumps were to making a clean landing. Patience was definately needed so bring a lot of it! I wasn’t even sure if I could get around the track so that was a consideration. After some time crashing on first pack, I began to figure things out and started making multiple sections at a time. By the end of my first battery and a lot of walking around, I finally did a full lap! My second battery was similar but I started to pick the speed up and took note of where the bumpy sections of the track were. I didnt do too many full laps but I was trying some more aggressive lines and jumps that the 1/8 buggies can make. I saved the aggressive jumping for the end of the day when a broken bike wouldnt matter as much.

Here are some key points for me having a successful track session:
1) Do some pre track day practice. Make sure you are comfortable making tight corners around predefined markers.
2) Set a goal. For me it was simply to make at least 1 full lap without crashing no matter how slow I was.
3) Square up your bike to the jump face! These bikes get crazy if your off line or trying to correct direction at the face of a jump. On small jumps I did notice I could power thru a bad entry to a jump with more throttle and the bike would straighten out enough to land ok.
4) Avoiding rough sections may conflict with being safe in the middle of the track but it does pay off if you can select your lines. So do a track walk and notice the bumpy sections and where the smooth lines are. A few corners had bumps right in the middle that really messed up the balance of my bike. During a lean the bumps would push on the crashbars causing all sorts of havoc, so just like in motocross, I saw that I was hitting my corners better when I took corners wide for instance, because it was smoother further out.
5) Take video if you can. I attach my Canon powershot to a baseball cap with a 1/4in screw for smooth hands free recording until I get a gopro. Even if you don’t post it on youtube, its great to watch in slow motion what your bike was doing in different situations either by your control or by setup so its gives you good info for next time.

Time to work on my setup for next time. Here’s some pics and video from the day. Hope you like it.

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