It’s hard to imagine that this time last year we were still wiring up the Rock Bug (see “Rock Bug Weekend Update for January 24, 2009”).  Despite all of our best efforts to have the Rock Bug ready to race 2009 King of the Hammers (KOH), its highly custom Scat V4 motor decided otherwise.  Literally one day before the race, severe lack of engine performance forced driver Tracy Jordan and the Rock Bug to bow out of the 2009 KOH competition.

It was a tough blow, especially given the amount of time and energy devoted to the Rock Bug project.  There was little time to feel bad about it though as the 2009 W.E.Rock rock crawling season was about to begin.  So we were all back at it trying to make the Scat V4 motor happy.  It took us the first two W.E.Rock competitions before we were able to get the Scat V4 motor under control.  Once we did though, the fate of the Rock Bug had permanently changed. 

With a perfectly running Scat V4 engine, Tracy Jordan and the Rock Bug seemed unstoppable, taking home 1st place spots in the final two W.E.Rock competitions.  Shortly after, the 2009 W.E.Rock season ended on the highest note we could ask for. Tracy Jordan and the Rock Bug won the 2009 W.E.Rock Grand Nationals (see  “W.E.Rock 2009 Grand Nationals – Tracy Jordan & The Rock Bug on the Shootout (Part 2 of 2)”) which is one of the highest rock crawling awards of the year.  Life was good.

With a full year of rock crawling competition (and three victories) under its belt, we’re more ready then ever for this years 2010 KOH competition. Instead of rushing to put together a brand new concept vehicle, we are now able to take our time and focus on many of the smaller items we ran out of time for last year.  We spent most of this year’s  preparation on cooling (larger transmission cooler, radiator cooling fins, oil sump scoop), modifications to comply with new rules (rear light bar, bladder style fuel cell with firewall, window net changes), and small go-fast improvements (higher performance alternator, on-board tools, fresh air system).  All in all, the Rock Bug is now looking ready to race.

The Rock Bug will be back on the road tomorrow heading over to Gerald’s place for final wiring on the new electrical goodies.  After which, Tracy and the Rock Bug will be heading out to the KOH lake bed for some final tuning.  Set your calendars for February 12th, 2010 which marks this years KOH race day.  Hope to see you out on there!

A picture of the Rock Bug sway bar mounted in front of the rear axle.

A few months back, a client came into our shop and asked a very thought provoking question. Does it matter if the rear sway bar is mounted in front of the rear axle or behind the rear axle? The understanding by the client was that placing the rear sway bar closer to the front suspension (in front of the rear axle) would have a greater negative effect on the front suspension then mounting it further away (behind the rear axle).  Is this really the case?

I have always struggled with this as I couldn’t see how placing the sway bar in front or behind the axle mattered in terms of effecting of the opposing suspension.  So, I figured I would break out the old engineering paper and geek out a bit with a few static diagrams to help better understand what’s going on.  Disclaimer – The purpose of this blog post is only to draw attention to the problem and create a good platform for debate. I am in no way taking a position of authority on this problem and am only looking to better understand the question myself.

The static diagram below starts with a force (Fi) on the passenger sway bar and follows the effect of Fi through the passenger sway bar, the bar itself, and the driver sway bar with Wd and Wp representing the weight of the axle.  In the end, the static diagram shows the net effect on the chassis as a resulting Moment (Mv1y) with vertical forces Fd2z and Fp1z and moments Md2x and Mp1x being equal and opposite.

Therefore, according to this static diagram above, mounting the rear sway bar in front of the rear axle should have the same effects on the front suspension as mounting the rear sway bar behind the rear axle as the Moment (Mv1y) would be the same with all other vertical forces (Fd2z & Fp1z) and moments (Md2x & Mp1x) cancelling each other out.

Your thoughts are encouraged here so please leave your comments for all to see, read, and digest.  As always, I am happy to be both challenged and corrected on any issue and look forward to updating this blog entry with more details as they are presented.

UPDATE [17-Dec-2009] – How About the Sway Bar’s Position in the Vertical Plane?
The above analysis focuses on a sway bar’s effect in the horizontal plane (front & back) and takes the position that in this plane, the effectiveness of moment Mv1y is equal along the entire x-axis.  Thanks to an awesome thread on Pirate4x4, another great question came up, one that I have never considered prior to hearing it.  Does it matter where the sway bar is mounted along the vertical axis (up & down).  After studying this question myself, I have to take the side of yes it absolutely matters.  Grabbing the same old engineering paper once again, here is a static diagram looking at the forces on the bar in relation to the vehicle’s roll center (detailed toward the bottom of the paper).

In terms of effectiveness, the position of the sway bar in relation to the vehicles roll center along this vertical plane does matter.  What is so interesting about this case is it would be easy to assume that whatever ineffectiveness the sway bar has can be overcome by simply installing a heaver sway bar.  Although this is true, larger diameter sway bars result in a smaller allowable angles of deflection (how much twist the bar has before it yields).  Therefore, if you are building a multi-purpose rock crawler / rock racer, it very well may be best to position the sway bar as close to in-line with the vehicle’s roll center as possible in this vertical plane.  Thoughts?

The Rock Bug as Seen in Dirt Sports June 2009 Issue of Masterpiece in Metal

“Masterpiece in Metal”, a monthly feature by Dirt Sports magazine, has been at the forefront for debuting the cleanest & most innovative off-road rigs ever to hit the the market.  Starting last November, we worked countless hours creating our own masterpiece dubbed “The Rock Bug”, a concept vehicle aimed at changing the way we all look at lightweight off-road performance.  When Dirt Sports recognized this innovation and asked the Rock Bug be part of Masterpiece in Metal, our long efforts had officially been recognized.

Little did we know, what goes on behind the scenes to make the Masterpiece in Metal feature so amazing is nothing short of insane.  The Rock Bug would have to be taken to the private California studio of ace photographer Boyd Jaynes for an exclusive 12 hour long photo shoot.  In addition, the Rock Bug would have to be “brand new” or “unused” so all detail in workmanship could be preserved for the feature.  Although both of these requirements make perfect sense, getting ready for King of the Hammers 2009 and scheduling time for a photo shoot before hand is something of a challenge.  Luckily for us, Boyd fully understood these struggles and patiently worked around our schedule. We finally had our session with Boyd on February 20th, just one week before the start of King of the Hammers 2009, and spent the entire day in his studio prepping the Rock Bug.

Then, three months later, the June 2009 issue of Dirt Sports would hit the stands and mark our official place in Masterpiece in Metal history.  On page 52, subtitled “In the mad pursuit of everything lightweight, Spidertrax produces a stunner”, Craig Perronne writes the incredible story of what came to be the Rock Bug along side the amazing photography work of Boyd Jaynes.  Now, thanks to Jim Ryan of Dirt Sports, you can download the entire Rock Bug Masterpiece in Metal article right from our blog free of charge!  So enjoy the article, which is available below in both low & high resolutions, and if you haven’t already subscribed to Dirt Sports magazine be sure to check it out.

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Although the title clearly gives away the ending, the story that leads up to this is nothing short of incredible.  I’ve decided to mix up this blog entry a little different to those past.  Instead of an overall summary followed by a days worth of videos, this time around I’ll walk you through each course, as it unfolded, all the way up to the Shootout.

Course B4 | Saturday @ 10:13 amBy the luck of the draw, Tracy & The Rock Bug would be the first to run B4.  Before the event started, it was projected that B4 would be the crowd favorite due to a massively difficult climb called “The Terminator” (6:30 in).  However, because this climb was optional and worth only 5 bonus points going over and 10 bonus points going back, Tracy started the trend off early and decided not to run either bonus for fear of losing more points then gaining.  This trend would then be followed by the entire Pro Mod class, eliminating “The Terminator” from this competition.  Tracy finished the course with a +8.

Course B1 | Saturday @ 11:21 amPulling up to this next course, word was no one had completed B1 yet.  Unfortunately, this fate would not change as B1 got the best of Tracy & The Rock Bug.  Although they didn’t complete the course, they did manage to secure a few progression gates and finished with a +37.  In the end, only 2 teams on Saturday were able to complete this course, Brad Lovell and Shannon Campbell.  The best score, held by Shannon, was +29 which was just 8 points better then Tracy.  So despite the lack of finishing, this course would not knock Tracy out of the competition.  Check out the video at 3:25 in where the Rock Bug shows off its incredibly low CG in a near roll.

Course B2 | Saturday @ 1:37 pmOnce again, pulling up to the next course B2, not one person had completed the course yet.  As if to prove something from the last run, Tracy was on a mission with the Rock Bug and would not only be the 1st to complete B2, but would end the day with the 2nd best score for the course of +2.

Course B3 | Saturday @ 2:20 pmThe last course of the day and so far so good as Tracy and The Rock Bug were in amazing form.  Our old XTS rig, driven by Rick Mooneyham, was running on the adjacent course and there is a nice surprise for you at 1:00 in.  Tracy finishes this course with a solid score of –3 and ends the day in 3rd place with +44.  Brad Lovell ends the day in 1st with +33 and Becca Webster in 2nd with +37.

Course A4 | Sunday @ 10:52 amBecause Tracy drew 1st on Saturday, today he would have the chance to watch some rigs run first which helps plan your attack.  Tracy would end up with the 2nd best score of the day on A4, a +1.  Becca Webster, who was on fire on Saturday and in 2nd place going into today, finished this course with the best score of the day –1.  Although Tracy & The Rock Bug were doing great, the pressure was on to catch up with both Becca and Brad.

Course A1 | Sunday @ 11:55 amAdding to the “urban war zone” course decor, A1 starts off by driving into the back of an old beaten Military truck bed!  Personally, I thought is was pretty innovative so hats of to the Kleins’ for creating such a unique course.  What made this course so challenging was maneuvering through the military truck bed.  It was so slippery in the bed that getting in and out all while avoiding cones was near to impossible.  Tracy finished with a good score of +16.  However, Becca got hung up in A1 and finished with a +39.  So in just one course, Tracy jumped ahead in points with Becca and the competition got that much more interesting.

Course A2 | Sunday @ 2:36 pmAnother incredibly difficult course that required a lot out of the spotter.  Congratulations to Jason Jordan for getting Tracy and The Rock Bug through A2 with one of the best scores of the day, +22.  Tracy has now passed Becca with a healthy margin so the race was on to catch up with Brad, the leader this far.

Course A3 | Sunday @ 2:58 pmWith no line in front of him, Tracy rushes over to A3 and quickly walks the course before starting the Rock Bug.  The pressure was on now as Brad was in the lead with Tracy in 2nd place.  Tracy not only had to do well on this last course, but he had to do extremely well if he wanted any chance of winning this Finale.  Brad had gotten a –1 on this course, which has an amazing feat, and Tracy knew he had to beat this score.  As he has shown us in the past, when the pressure is on Tracy works the Rock Bug in absolute amazing form.  He walks A3 and gets the best score of the day, –11!

The Shootout | Sunday @ 5:45 pmThis is it, the final Shootout.  The top 6 teams this far compete in the end all of end all courses.  Points are cumulative for these 6 teams, so scores from Saturday and Sunday are totaled and added to the final score of the Shootout.  Tracy is now sitting in 2nd place, just one point away from Brad Lovell who is in 1st.  Vehicles run in reverse order of score, so Tracy would run and Brad would follow.  The Shootout was near to impossible, with only 2 teams so far making it in the Pro-Mod class, namely Shannon Campbell with a +8 and Bill Kunz with a –1.  Tracy had to bring his A game if he wanted to take Brad head on.  Not only does Tracy bring his A game, he completes the Shootout with the best score of the day, –12!!!  Brad follows behind and suffers a devastating blow.  On the 2nd set of gates, he rolls his vehicle and is unable to recover.  Tracy & The Rock Bug win the Series Finale!!!

So, there you have it.  Two days of non-stop action with Tracy & The Rock Bug winning the series finale and taking 2nd overall in the series for points.  What an amazing year it has been!  We also have to give a special congratulations to Brad Lovell and his team Lovell Rock Racing for winning the 2009 W.E.Rock Pro-Mod Series with their Spider 9 powered rig.  Next up is W.E.Rock’s Grand Nationals, October 3-4 in Farmington, NM.  With the Rock Bug running in top form, the Grand Nationals is going to be one event you don’t want to miss.  See you there!

Oroville’s new man made course may be the toughest one yet.  Construction photos courtesy of Werocklive.

Less then a month ago, Reno Rock’s hit the Sand’s Regency Hotel and quickly became the most talked about competition of the year.  For Tracy & The Rock Bug, the entire 2009 rock crawling series came down to this one single event.  If they wanted any chance of winning the series, they had to finish 1st in Reno Rock’s.  With the pressure on, Tracy & The Rock Bug showed the world, once again, why they compete with the best out there.  With an amazing 2 day performance, Tracy & The Rock Bug dominated Reno Rock’s and took home a 1st place finish.

Now, heading into the season finale, Tracy & The Rock Bug are sitting 2nd in points for the series.  They have a long way to go to beat the series leader, Brad Lovell of Lovell Rock Racing, but as we know anything can happen in the finale.  Here are your series standings so far for both Unlimited & Pro Modified Classes:

The only notable upgrade made to the Rock Bug, in preparation for the season finale, was the installation of 2 chromoly shift forks for the Stak D300 2 Speed Transfer Case.  With the help of Ken from Stak, we manufactured a billet 4130 chromoly shift fork and normalized & heat treated the entire welded shift fork assembly.  Last but not least, we opted to weld the shift fork assembly to the shift rail instead of running the factory set screw.  The end result created an incredibly strong shift fork (about 8 times the strength of factory) that should hold up to the high demands of competition abuse.  Only time can prove that statement though, so we’ll have to wait and see how this competition upgrade pans out.

The “Tracy Jordan” Special Edition 4130 Heat Treated Shift Fork

The W.E.Rock season finale will take place in Oroville, CA this weekend (July 18-19th) and is guaranteed to be one action packed event.  For those able to attend in person, the event site will be held at Surplus City Jeep Parts and gates open at 9 am on Saturday.  For those unable to attend in person, fear not as live coverage will be available online.  Pirate4x4 typically broadcasts the best live coverage on the planet, so keep an eye on their main Home page for more details.  Also, don’t forget to follow me on  Spidertrax’s Twitter Account for additional live competition coverage.  As always, I’ll post a blog entry at the end of each day of competition, complete with story and videos.  If you want to get these blog updates automatically by eMail, you can subscribe to our Blog using FeedBurner.  Now, I have to pack and get ready for Oroville.  Good luck to all the teams this weekend!