The Blog of Spidertrax

1. Introduction

The seemingly unending debate of outsourcing & offshoring is back on top of America’s “What Matters Most” list. As the proud co-owner of Spidertrax Off-Road, an American company that designs & manufactures its products in-house, it should come of no surprise what side of this debate I sit. My interests however in publishing this article lie not in politics but in engineering ethics, focusing not on “you get what you pay for” but rather “you didn’t get what was advertised”.

Below is a detailed mechanical & material analysis between a Spidertrax JK Wheel Spacer (Domestic) & an “Unnamed Brand”* JK Wheel Spacer (Import). The take away here is not so much one product being superior to another. The issue is with the import wheel spacer being advertised as using 6061-T6, the same high quality material used in our domestic wheel spacer. Although these claims leave the impression that both products are virtually identical, the analysis detailed below tells another story.

*Before moving onto the results, I wanted to clear up any confusion ahead of time regarding the use of “Unnamed Brand”. The conflict in sharing this identity comes from singling out just one manufacture as we have duplicated these same test results from other import wheel spacer manufacturers. So, in an effort in “taking the high road” the import manufacture in this test will remain nameless and be referred to only as “Unnamed Brand”.

2a. Tensile Test (Aluminum Spacer)

Both domestic and import JK wheel spacers are advertised as using “6061-T6” aluminum. As referenced on MatWeb, Aluminum 6061-T6 should provide a minimum Tensile Strength (Yield) of 40,000 psi & a minimum Tensile Strength (Ultimate) of 45,000 psi.

As shown above, our domestic wheel spacer exceeds the minimum requirements for 6061-T6 (as advertised). The import wheel spacer, on the other hand, is off nearly 35% in terms of Tensile Strength for 6061-T6 (not as advertised). What is just as, if not more, concerning is the closeness in value between Yield Strength and Tensile Strength for the import spacer. This closeness in value suggests the material is cast and not billet (also not as advertised).

2b. Chemical Analysis (Aluminum Spacer)

This test confirms that, although there are differences in material composition as shown below, both our domestic wheel spacer & import wheel spacer conform to a 6061 series grade.

There is an important distinction made when combining the results of both the tensile test & chemical analysis though. When combined, the results clearly show our domestic wheel spacer is indeed billet 6061-T6 (as advertised) while the import wheel spacer is cast 6061 (not as advertised).

2c. Hardness (Wheel Stud)

The last test is a cross sectional hardness traverse on the wheel stud (a component which is pressed into the wheel spacer).

The results, as per SAE J429, indicate our domestic wheel stud exceeds Grade 8 specification (as advertised) while the import wheel stud meets Grade 5 specification (not as advertised).

3. Conclusion

As shown in the above analysis our domestic wheel spacers are manufactured from billet 6061-T6 aluminum and run Grade 8 wheel studs as advertised. Although the import wheel spacer is advertised using these same high quality materials, the above analysis proves it is manufactured out of nothing more then cast 6061 running Grade 5 wheel studs. “Buyer Beware” certainly doesn’t capture these outrageous findings.

For reference, you can also download a copy of the complete Domestic & Import metallurgical reports. All testing as detailed in this article was performed by Colorado Metallurgical Services (CMS). Spidertrax Inc. (Spidertrax Off-Road) is not affiliated with or a subsidiary of CMS. 

It has been a wild year for XRRA rock racing. In the past, each XRRA event had two courses where one rock racer would run on each simultaneously.  Even then, the action was intense but the changes made to this year’s format brought rock racing to a whole new level.  New for 2010, each XRRA event brings just one course where two rock racers compete side by side.  Without question, the level of competition & intensity among drivers is beyond anything seen before.

The 2010 season finished this past weekend in Cortez, CO and in the end of 8 brutal rounds of competition, Shannon Campbell proved the master of this new XRRA format. He not only took the 2010 season title but he did so by taking 1st in all 8 rounds of competition, something that has never been done in XRRA history. Derek West, Brian Shirley, & Levi Shirley rounded out 2nd, 3rd, and 4th respectively for the 2010 season with all 3 rigs powered by Spider 9 axles & components.

In the end, we want to thank all of the XRRA teams who supported Spidertrax throughout the 2010 season. In total, 12 of the 18 rock racers in Cortez were running Spider 9 axles & components which was awesome to see.  For those looking for more XRRA action, we took over 50 videos from last weekends competition and posted all of them online (links below).

2010 XRRA Round 7 Video | 2010 XRRA Round 8 Video

When I bumped into John Gardner, Media Director of Miller Motorsports Park, I couldn’t help but ask “How big is this place?”. He responded with a smile “511 acres. I like telling people we’re 3-1/2 times the size of Disneyland with better rides.” He wasn’t kidding! I’ve gone to countless rock crawling competitions over the past decade and this one is easily among the best.  Put simply, W.E.Rock Round 4 at Miller Motorsports Park was THE rock crawling event of the year.

The battle was fierce all weekend long in both Unlimited & Pro-Mod classes with each team not only working on an event win but shooting for the 2010 Season Title. In the end, Dion Wakefiled & Jesse Haines rained victory by grabbing the Unlimited & Pro-Mod top honors for the weekend (final scores for both classes below).  Although not officially announced until October’s Grand Nationals event, the 2010 Season Title will go to Brent Bradshaw of Unlimited and Troy Bailey of Pro-Mod.

The “2010 W.E.Rock Round 4 | Highlights” video above is a small tribute and testament to the many teams running Spidertrax Spider 9 Axles & Components during this event.  To the many drivers & spotters who support us and what we do here, thank you!

The Grand Nationals, which is rock crawling’s All Star Game, heads back to Miller Motorsports Park on October 1st & 2nd.  We’ll be there again providing live updates via Twitter (http://twitter.com/Spidertrax) and hope you join us in person or online for what promises to be another amazing event.

This is a follow-up to our very popular "Domestic vs. Import Unit Bearings – Bearing Play Comparison" video posted back on October 15, 2009. In that video, we discussed the differences between domestic & import grade unit bearings using Kevin Sacalas’ domestic grade Spidertrax Unit Bearings for our case study.

Since that time, Kevin has now racked on over 2300 miles of extreme desert racing on these same unit bearings with his nearly 5000 lb race vehicle. So how are our unit bearings holding up? Watch the video and see for yourself.

Brad & Roger Lovell, also known as the Lovell Brothers, have done something over the past six years that others have only dreamt about. They’ve taken a passion of theirs, in this case professional rock crawling and rock racing, and turned it into a full time career. This passion fueled by the reality that winning keeps their lights on propelled these brothers on a fast track to success. Although rock crawling and rock racing is still a big part of their lives (both are very active in the 2010 rock crawling & racing season), the need to push and sharpen their skills further remains vital for staying relevant in the ever changing off-road competition world. So, when we got the news that Brad decided to take on short course racing, we were not at all surprised.

At first, it may seem that short course racing is as far from rock racing as underwater basket weaving. After my trip out to Crandon, WI this past weekend to witness Brad’s first short course competition, I can safely say rock racing and short course racing have much more in common then I initially thought. In summary, short course racing takes a dirt track with tight turns/jumps/whoops, puts a dozen or so 900+ horsepower trucks on course, and has them race to the finish. To get an idea of just how fast these guys & girls are racing, check out the quick video below of my standing, arguably to close, on course at the start of one race.

Brad is officially taking on the Traxxas TORC Off-Road Series this year with his brand new Pro Light truck powered by Spider 9 axles & components.  Last weekend was Brad’s first ever short course race and all things considered it went rather well.  The truck is still in one piece (hard to pull off your first time out), our Spider 9 axles performed amazingly, and Brad is one step closer to mastering the art of short course racing.  Although I wouldn’t expect many podium finishes from Brad this year, rest assured he is the kind of driver that will push and push until he’s on top.

I have posted two videos below (Part 1 and Part 2) of Brad’s first race out in Crandon, WI on June 19th.  Although he did race on June 20th as well, he was taken out very early due to a busted tie rod from contact by another vehicle.  Because his time on course was literally about 1 minute I have elected not to post this race online. Brad’s next short course race will be at the Bark River Raceway in Bark River, MI on July 10 & 11th.

2010 Traxxas TORC Round 1 – Brad Lovell (Part 1 of 2)

2010 Traxxas TORC Round 1 – Brad Lovell (Part 2 of 2)

When we created the Rock Bug, designing a high performance rear steer axle was a must for driver Tracy Jordan.  We understood Tracy’s position on this one as anyone who can master the art of rear steer is virtually unstoppable in the rocks and Tracy Jordan is without question one of those masters.  Unfortunately, with nearly twice as many W.E.Rock competitors in the more restrictive 2009 Pro-Mod class, which doesn’t allow rear steer, Tracy decided to run a solid rear axle in the Rock Bug in an effort to compete against as many drivers as possible. Although the 2009 competition was a complete success for both Tracy and the Rock Bug, you could tell Tracy was missing his rear steer axle.

Now we’ll fast forward to March 27th, 2010 as W.E.Rock kicked off a brand new rock crawling competition season in Oroville, CA.  Although Tracy would run the Rock Bug’s rear steer axle any chance he could get, word was the number of competitors in each class was inline with last year (around 12 Unlimited and 24 Pro-Mod rigs). So, like last year, the decision was made to run the Rock Bug as a Pro-Mod rig.  Then, literally 1 hour before the start of the competition in Oroville, everything got turned upside down.

As it happened, we discovered the morning of the event both Unlimited & Pro-Mod classes had nearly the same number of competitors (about 12 in each class).  Although the Rock Bug was set up as a Pro-Mod, there was no question that for the rest of the W.E.Rock season Tracy would be running the Unlimited class with the Rock Bug’s rear steer axle.  The question of the day though was what to do about this first event.  Do we run the Rock Bug in Pro-Mod and then Unlimited for the rest of the year eliminating any chance of capturing the season title? Do we attempt to run the Rock Bug as set for Pro-Mod (37” tires and no rear steer) in the Unlimited class, something that has to date never been done before, so that the season title could possibly be captured?  With no easy answer in site and now less then 1 hour before show time, Tracy calls for a coin toss.  Heads we run Pro-Mod, tails we run Unlimited.  I flipped the coin and tails it was.

Now making a very long story short, for the next two days Tracy Jordan battled it out with his Pro-Mod rig in the Unlimited class. This meant he would compete against rigs with larger tires and rear steer axles.  In the end, Tracy would prove once again why he is rained as one of the best rock crawlers in the world as he pulled off what seemed nearly impossible.  In a Pro-Mod rig, Tracy Jordan won Unlimited!

Tracy & the Rock Bug will be back competing in the Unlimited class  May 1-2 in Tucson, AZ and this time with 40” tires and a rear steer axle.  In the meantime, check out the video above of Tracy Jordan running the final obstacle of the competition, The Shootout, a course where only 1 other driver out of 12 was able to complete.  We also have a great collection of photos below from ace photographer Chad Jock showing off some of the many  teams running Spidertrax Spider 9 axles & components.

Tracy Jordan & The Rock Bug soaking in some Moab beauty. (Photo: Tim Magee)

It’s always nice to see recognition for one of the funnest projects we ever had the pleasure to work on. Tim Magee wrote a great piece coupled with some of the most amazing photography to date on the Rock Bug in this month’s issue of Crawl Magazine (Issue #21).  If you haven’t got your issue yet go ahead and steal your friends now. It is packed not only with this great article but in-depth coverage of this year’s King of the Hammers competition.

Once again a big thanks to John Herrick, Owner/Publisher of Crawl Magazine, for letting us post a digital copy of The Rock Bug article right here on our blog for free.  In addition, we called up Tim Magee and got a hold of rest of the photos from The Rock Bug photo shoot that didn’t make it into the magazine.  Hope you enjoy the article and photos as much as we did!

Download the full print article “The Rock Bug”, courtesy of Crawl Magazine.

                                    
Photos from The Rock Bug photo shoot that didn’t make it into the magazine.

Monster Jam | XORRA: Round 1

Monster Jam | XORRA: Semi-Final

Monster Jam | XORRA: Final

First, I have to confess.  The last time I went to a monster truck show was way back in the mid 1980s.  If memory serves me right, Bigfoot was the truck to beat back in those days.  Now fast forward 25 years and you will find that monster trucks take part in one of the biggest live motorsports events of all time.  Feld Entertainment’s Monster Jam is said to pull in more than 2.5 million people each year.  Vehicles like “Grave Digger” & “Monster Mutt” have literally become household names.  Come to think of it, my 4 year old son has a Monster Jam Xbox 360 game. Yes, they’re everywhere.

Now let’s jump to our end of the market.  The Weaver’s, who manage the XRRA rock racing circuit under the umbrella company XORRA, have talked about running a separate stadium type series for years now.  Nearly overnight, this concept of “arena rock racing” just got one step closer to reality. XORRA, with the help of XRRA driver Dan McDonald, struck a deal with Monster Jam to run one small arena rock racing competition during a live Monster Jam show.  The idea was to treat this first show as an exhibition or pilot in hopes the audience would like what they saw.  If they did, maybe arena rock racing had a future with Monster Jam.

With literally no prize money at stake (aside from any contingencies) and only two weeks before King of the Hammers, six XRRA drivers hauled out to Angles Stadium in Anaheim, CA to put it all on the line in front of nearly 50,000 spectators.  In the end, I think they put on one heck of a show!  Yes the courses were short and yes the XORRA portion went very fast.  However, all the XRRA drivers showed the highest level of professionalism anyone could ask for.  Just as important, the audience really seemed to enjoy the show.  Only time will tell if something comes out of all of this, but hats off to everyone involved for making it a true success.

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?