Meet the Rock Monster: FJ Cruiser Gets Beadlocked
Mods and Modding Product Reviews Wheels and TiresI spent the better part of three years searching for an aftermarket wheel that not only looked good cosmetically but was designed to meet the rigors of off-road conditions. I’m not sure why, but I’ve always been very picky when it comes to the style of a wheel. Generally speaking it takes a lot to impress me since I find many designs to be unappealing for one reason or another. As such, you can imagine my elation when I first laid eyes on the Rock Monster, a wheel that not only looked good, but was specifically designed with rugged conditions in mind. Hutchinson Industries, the company behind the Rock Monster series wheels, has been manufacturing heavy duty aluminum beadlock and run-flat wheels for the U.S. military for more than two decades. Their product lines are specifically targeted towards emergency recovery and military support vehicles in the field. These wheels have undergone extensive testing and have proven themselves again and again under rather extreme field conditions. Suffice it to say, they are designed to withstand some serious punishment.
Unlike a traditional one-piece wheel, the Rock Monster is a split-rim design where the outer facial portion of the wheel is removable. This two-piece design enables Hutchinson’s proprietary beadlock ring to be installed prior to wheel assembly. Once the beadlock is in place, the wheel is assembled, effectively pinching both the inner and outer tire beads between the respective rims of the wheel. This method for beadlocking is not only high effective, it’s also extremely safe. So safe, in fact, that Hutchinson Rock Monsters are the only beadlock wheel that has been approved by the department of transportation (DOT). Because Hutchinson holds military contracts, they are held to higher standards than traditional wheel manufacturers. As a result, these wheels are produced with extremely tight tolerances. They offer two different sizes of beadlock rings so you’ll need to know what tire you plan to use before ordering, to make sure you get the right size beadlock.
Assembly and disassembly of the Rock Monster wheels does require some patience, but once you’ve done one, it becomes somewhat systematic and the rest usually go pretty quickly. The molded rubber beadlock rings are fairly stiff and do require some force to get them into place. Once the ring is sitting between the tire beads, the tire is then placed over the inner rim (large portion) of the wheel. To seal the two halves of the rim, a flexible rubber gasket sits in a channel that runs just outside the bolt holes on the inner face of the outer rim. The inner rim joins the outer by aligning eighteen lugs, three of which are longer than the rest. These longer bolts are spaced equidistant from one another and are used as starter bolts designed to bring the two halves closer together before final assembly. As the gap between the two halves is lessened, the tire beads will seat against the rim and the shorter 15 bolts will become accessible so that the remaining nuts can be placed and tightened appropriately. Hutchinson recommends using a star pattern when tightening the nuts, torquing each nut first to 60 pounds, followed by a second pattern that torques each nut to 80 pounds. The biggest concern when closing the gap is to ensure the rubber gasket remains fixed in its channel. If it comes out, the halves will not seal properly, allowing air to escape.
Like most upgrade projects, I learned a few lessons along the way. Based on advice from Hutchinson, I purchased a set of TyrePliers to ease the process of disassembling the tires and rims. Forget popping a bead with traditional tire spoons. The TyrePliers allowed me to pop a single bead in about 30 seconds, with little to no effort involved. When it comes to lubricating the beads (to ease removal), some people recommend using vegetable oil or other products that can potential damage the tire or rim. I actually found that brushing the tire and wheel rim down with some soapy water before attempting to pop the beads works really well. You don’t have to worry about damage and it’s easy to wipe down afterward. Whether you’re running split rims or a traditional one-piece wheel, I highly recommend purchasing a set of TyrePliers as it will save you a lot of time and frustration both at home and in the field.
Another lesson I learned the hard way was related to tire balancing. I planned to run Interco’s TrXus MT mud terrain tire with these wheels – a 33×12.5 tire that weighs in at more than 70 pounds. Most mud terrains are difficult to balance using traditional methods so I decided to try a product called Dynabeads instead. Each tire contains 8-10 ounces of very small ceramic beads that are designed to auto-balance the tire as the rotational speed increases. Unfortunately in my case, there was still significant vibration due to lateral imbalances in the tires, so I had to resort to traditional balancing using strategically placed wheel weights. Before I could do this, however, I had to remove all of the ceramic beads, which required disassembling the wheels again. Thankfully, once I got the beads removed and the wheels and tires reassembled, traditional balancing did the trick, albeit with a whole lot of weight.
Update:
I’ve been running these wheels since late March of 2010 and I am still ecstatic over my purchase. They’ve taken repeated beatings on some pretty rough trails and even with the resulting scars, I still think these are some of the best looking wheels on the market today. And unlike a traditional beadlock that requires regular maintenance and re-torquing, the Rock Monster wheels are virtually maintenance free. I’ve repeatedly checked torque settings and kept a watchful eye for drops in air pressure, but I have yet to notice any problems with loose nuts or significant air loss. By choosing a beadlock design I never again have to worry about slipping a bead or tires spinning on the rim. And with the Rock Monster, I get this same great protection on both sides of the tire.
To be fair, there are a few drawbacks to this particular wheel. Firstly, these wheels are heavy, pushing 55 pounds a piece. So if you’re looking for a light-weight wheel to save gas mileage, these are definitely not the wheel for you. Keep in mind, however, that these wheels are designed for military use, specifically tailored to withstand bomb blasts and other potentially lethal circumstances. The second drawback to these wheels as that they require a lot more time to mount your tires. But for those do-it-yourself-ers out there, this is actually a benefit since you no longer need to take your tires and wheels to a shop for assembly. All it takes is a few tools and some patience. The third and perhaps most significant drawback to these wheels is the price – they are not cheap by any means. But like most products these days, you get what you pay for, and in my opinion, these wheels are well worth the asking price.
For those of you looking to purchase your own set of Hutchinson Rock Monster wheels, there are a number of retailers available. I purchased mine from Expedition One, an aftermarket parts manufacturer in California. If you have any additional questions about Hutchinson’s product line, I suggest e-mailing Hal Roth in their Sales department at hroth@hutchinsoninc.com. I’ve included some photos below of the Toyota-specific Rock Monster wheels.
Great looking wheels!
Can you confirm this are
33/12.50 x 17 ? I love the tires, just order a set of 35/12.50 x 17
Thanks for the feedback, Michael. Yes, the Toyota Rock Monster wheels are a 17-inch rim and I’m currently running Interco’s TrXus Mud Terrain tires in a size of 33×12.5, so you should be fine.
Very nice job on all of your research; well-balanced and informational.
My lovely bride and I are planning another Denali trip from our native Florida and I’m getting some excellent ideas from all your work here. Thanks. As a researcher myself, I appreciate the time it took to gather and discriminate valid from unreliable info. Additionally, your writing style is easy to read and kept my ADHD at bay 😉
Questions on your choice of wheels:
1. The Hutchinson Rock Monster looks like the model I’ll choose. However, remaining with the 17 OEM sizing, or moving down to a more trail-friendly 16 rim will need to be decided. What technical points were considered for staying with the 17 on your FJ?
2. Did you find an appreciable price-point variance during your vendor search?
Curiously, I’m also currently running the same Nitto’s you replaced (on our previous cross-country to Denali) and have nothing but praise for them. They are wonderful for what they are designed for and performed superbly during our Imogene ascent – but as you reported, as a AT tire the mud/snow/slushy performance can be improved. Snaps to you, I’m now looking seriously into the TrXus MT’s for all the same reasons for this trek we’ll be crossing during the winter months and no doubt will encounter quite a bit of the liquid stuff.
As I’ve only recently discovered your site, I’ve still some reading to do. Looking forward to more good info. Keep-up the great work here!
Michael,
The Hutchinson Rock Monster is only manufactured in a 17″ rim size, so there really wasn’t a choice in that area. As far as price differences go, the Rock Monster wheel is priced considerably higher than most standard wheels, I’ll agree. However, you really need to compare apples to apples in this case. When you compare the Rock Monster to a similar Raceline product for instance, the price difference is not all that noticeable. A good beadlock wheel is going to be more expensive, regardless of the brand you choose. And a dual beadlock system that works as well as the Rock Monster doesn’t come cheap. But when you consider all the benefits you gain when running the Rock Monster, the price becomes much more tolerable. Lastly, if you’re curious, I did a complete review of Interco’s TrXus Mud Terrain tire here. You might find the long-term results helpful in your tire research. Thanks again for your comment and good luck on your Denali trip!
Also, was there a significant impact on fuel consumption after the RM’s and TrX’s compared to stock rims and Nitto’s?
Michael,
In my case, I already had a significant amount of heavy (weight-wise) modifications completed before adding the Rock Monster / TrXus combo, so the difference in mileage wasn’t particularly noticeable. I suspect you will probably lose 1-2 mpg if you’re upgrading from a completely stock setup. But if you’re already running larger aftermarket tires and wheels, the difference will most likely be negligible.
I was wondering if you used these on a daily driver? As wheels would be the first aftermarket purchase for my FJ that will be my dd, would it be reasonable just to go straight to the rockmaster and not beat around the bush?
Sparkplug,
Indeed I do use these wheels on the FJ Cruiser as a daily driver. As indicated in the review, the Rock Monster wheel is quite heavy and as such it will have an impact on your daily driving mileage. But other than a slight reduction in mileage there’s no reason they cannot be used for every day street use. Running these wheels daily saves me from owning two separate sets of wheels and when I’m ready to hit the rocks, there’s no need to swap wheels and tires beforehand.