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Can a leaf-sprung vehicle be endowed with the ride and compliance of a coil-sprung vehicle? After installing a set of Terrain Tamer parabolic spring on our 1973 FJ40 Land Cruiser, I’d answer that question with: Close. Astonishingly close. Just one anecdote—when I first took Roseann for a ride after the installation, we’d not even got off our neighborhood byway onto a main street before she said, “Wow.” First, if you’re not familiar with the concept, please read this, then this. But, briefly, a parabolic leaf spring is shaped in such a way that a single leaf can provide progressive resistance as it is compressed—it is, in essence, an extremely elongated parabola, thus its name. By comparison, the traditional standard leaf, stamped from flat bar stock, requires several additional, increasingly shorter leaves to provide progressive resistance, and those additional leaves produce substantial interleaf friction, reducing compliance and ride quality—especially in the case of a heavy-duty spring pack for a 4x4 vehicle, which might comprise eight, ten, or even more individual leaves. Theoretically a parabolic spring can be built with just a single leaf, but most systems use two or sometimes three, to provide backup in the event of one leaf breaking. But those leaves only contact each other at the very ends, via a thick anti-friction pad, so interleaf friction is nearly nonexistent. In fact, shocks for parabolic springs are valved more firmly to compensate for that reduced friction and the lack of self-dampening. Like a coil spring, a parabolic spring would continue to oscillate for some time after a bump if not damped. Terrain Tamer has been making parabolic spring kits for Series Land Rovers, Hiluxes, and several other (mostly non-USA) vehicles for some time; not long ago they added applications for 40-series Land Cruisers, and offered to provide me with a set. The kit is exhaustively complete: four springs, four nitrogen-charged twin-tube shock absorbers, a steering damper, greasable anti-inversion shackles, and U-bolts. My kit also included TT’s own synthetic elastomer Pro bushings, which the company claims combine the vibration-absorbing properties of natural rubber with the durability of polyurethane. The bushings come with a specific molybdenum disulphide grease. Terrain Tamer’s shock absorbers have an excellent reputation; however, I had an opportunity to try a set of Koni’s Heavy Track shocks. Koni’s Heavy Track Raid is the best expedition shock absorber I have ever used on overloaded Defender 110s in East Africa, so I jumped at the chance to install the slightly lighter-duty version on the 40. Installation of everything was completely straightforward, with the additional benefit that the Konis are not nitrogen-charged and thus do not have to be forcibly compressed to fit them. Weighing the OME springs, then the parabolics, drove home one of the salient advantages of the latter: the swap removed 80 pounds from the Land Cruiser. With it all bolted up, the Land Cruiser’s fender height was within a quarter inch of where it had been with the OME springs installed—the (to me) ideal 50mm/two-inch lift for an FJ40 intended for all-around use. Trying to suppress unrealistically high expectations—this is still after all a leaf-spring suspension—I headed out for a short drive. I needn’t have suppressed any expectations. The ride was, in a word, transformed. One might demur by pointing out that the evicted OME springs were five years old, but I’d replaced and lubed their anti-friction pads not long before, and regularly greased the shackle bushings. No—this was a transformation. Harshness over minor irregularities in the road surface was simply gone, with the partial result that normal rattles and buzzes in the 40 seemed cut in half. Suspension action over larger holes and humps was astonishingly compliant. I turned around and went back to the house to take Roseann for a ride, and she was just as impressed. I let the suspension “settle” for a few weeks. From the side I then noticed a very slight droop at the rear—no more than a half inch, but I loathe a non-level vehicle. This was undoubtedly due to the substantial rear rack on the 40. So I installed a set of OME rear shackles, which are about an inch longer than the Terrain Tamer versions. “Problem” solved. Stout Equipment rack (pre-parabolics) A few days ago we took the 40 up into Redington Pass, east of Tucson. This route combines a severely degraded dirt road up the pass with several challenging 4x4 trails off it. The Terrain Tamer parabolics—along with the Konis—simply took 90 percent of the sting out of corrugations and potholes that were punishing with standard leaf springs. Once on the trail, the extra compliance was obvious, keeping all four tires in contact with the surface in spots where I typically lift a wheel. Impressive. Even in a video of a simple drive-by (see the Firestone M/T2 tire review) you can see how much easier the ride is. Over my entire 40-plus-years ownership of the FJ40, no modification I’ve done has had anywhere near such a profound effect on the very nature of the vehicle. Obviously it will be some time before I can attest to the durability of these springs, but the technology has been around long enough to be well-proven. If you own a leaf-sprung Land Cruiser or Land Rover, I cannot recommend Terrain Tamer parabolic springs highly enough. Terrain Tamer is here. The (just announced) U.S. importer, Valley Hybrids, is here. Query regarding availability. View the full article

Why would anyone mount mud-terrain tires on a vehicle that rarely leaves the Sonoran Desert? Several people asked me that question, after I switched from the all-terrain tires I’d run for a decade or more on my 1973 FJ40, to a set of Firestone Destination M/T2s (after also considering the company’s Destination X/T, which has an all-terrain-oriented tread pattern). My answer surprised some of them, who teasingly assumed I’d gone for the butch looks. And there’s no denying that the MTs look just right on an FJ40. However . . . Most people assume that a mud-terrain tire is good for one thing: mud. And indeed the open, aggressive tread blocks of an MT tire are known to be effective at digging down for traction in shallow mud, and for the ability to shed sticky mud that tries to cling to the tire and fill in the tread so all you’re left with is a slick. Often a brief burst of throttle (a relative concept in an FJ40, granted . . .) will clear the tread and regain lost traction, when the same tactic would fail to do so in an AT tire with more closely spaced tread blocks. However, an MT pattern is excellent at other tasks—and in fact better than an AT at some of them. Consider deep sand, which most people would think is anathema to a mud-terrain tire. Not so—if it is aired down to the same level as one would an AT, an MT tire will perform perfectly well in sand, offering excellent flotation and traction—as long as you’re careful not to continue spinning the tires if you bog down. While any tire will bury itself when you do this, an MT tire will do so with considerably more enthusiasm. But there’s an upside I discovered, somewhat to my surprise although it makes perfect sense: if you are bogged (in any substrate) and deploy traction boards such as Maxtrax to extricate the vehicle, an MT tire will grip the traction board far more effectively than an AT tire, easing the recovery and reducing the risk of spinning and melting the studs on the board. I noticed this repeatedly while running sand recovery scenarios at the Overland Expo. Some vehicles with stock tires that barely had enough tread to qualify as an all-terrain pattern had an extraordinarily difficult time getting onto the board without wheel spin, while those on mud-terrains would tractor right up and out with zero drama. What about mud-terrain tires on rocks? Most of the 4x4 trails near where we live in southern Arizona involve a lot of rock crawling in low range, and at this a mud-terrain tire is certainly equal if not arguably superior to an all-terrain tire. To simplify a complex relationship, there are essentially three ways a tire can grip the surface beneath it. Molecular grip. This is dependent on the formulation of the rubber in the tire. An extreme example of molecular grip is a high-performance sports-car tire. A tire with high molecular grip will have a soft compound good for sticking to the road but not good for long-term wear. While some tires designed for extreme rock crawling employ such compounds, it’s not desirable in a tire expected to last for tens of thousands of miles of use. Micro-mechanical grip. This occurs when the texture of the tire’s tread keys into tiny irregularities in the substrate. Macro-mechanical grip refers to the ability of the tire’s tread to mold around and grip larger irregularities, or indeed entire objects on the surface such as boulders. Number three is where the large, discreet tread blocks of an MT tire excel. Think of the aggressive tread in the Vibram sole of a heavy-duty backpacking/mountaineering boot for a corollary. Indeed, when aired down properly, I found the M/T2s to perform exceptionally well on the rocks of the standard 4x4 route I use for reviewing vehicles, in Redington Pass east of Tucson. The M/T2s at 22 psi wrapped around rocks for maximum traction. The aggressive side lugs gripped especially well, and given the the thickness of those lugs plus three-ply sidewalls I didn’t worry about damaging the tires even when aired down to around 20 PSI. Are there downsides to a mud-terrain tire? Of course. MT tires are noisier on pavement than all-terrain tires, to a greater or lesser extent depending on many factors, but basically . . . noisier. In an FJ40 this is not as big a factor as it would be in a more intrinsically quiet vehicle, but it’s still noticeable. My impression is that the Firestone M/T2 is quieter than the last set of MTs I had on the FJ40, but it’s been a while so that’s not hard evidence—and new tires are typically quieter than those with a few thousand miles on them. Around town the noise is no greater than a mild hum and barely discernible; at highway speeds it’s more of a medium/high-pitched whine. More: MTs do not offer the same traction on pavement as an AT tire, for both handling and braking. You must adjust your driving to suit. You will also lose some fuel economy; just how much will again depend on several factors. My impression is that I’ve lost about a half mile per gallon on the 40 (figuring on my recent average of 16 mpg on the road). All these factors were in play during my decision-making process. Years ago, when our FJ40 was our only overland vehicle (in fact for a time it was our only vehicle, period) all-terrain tires made more sense given more extensive use on paved roads and highways. Now, since we have a 70-series Troop Carrier for travel, the 40 is reserved for closer trips and for 4x4 training classes. Thus the M/T2s made perfect sense. I’ll be curious to see how they look and sound with a few thousand miles on them, but for now I’m very happy with the choice. View the full article

Number 3 is at the printer and will be mailing out in mid- and late-January. And we are really pleased with the content. It’s packed full of adventure, equipment, history, field arts, and much more. And there is a slight nautical theme as well. Below is a sneak-preview of some of the content. A reminder of our publication schedule: July (print issue with digital version) October (all-online content) January (print issue with digital version) April (all-online content) If you subscribe now, your subscription will begin with the October online-only issue, Vol. 1, No. 2 (but you will have digital access to No. 1 as well, so it’s a nice bonus). All-digital subscriptions are $39, and 2 print + 2 online are $49 (we also offer international rates). Join us today, and never cease exploring. A family sets sail around the world thirty years (and on the same boat) after their first circumnavigation—this time with the third generation in tow. (Dito Abbot) Seeking sunken treasure in Dorset. (Roseann Hanson) Why is Jonathan tossing a ship’s biscuit? Which is the best portable water container? View the full article