May 6, 2017

Product Review: Giant Loop Pronghorn Straps


All Rights Reserved © 2015 Thomas W. Day
A Giant Loop-supplied picture of the alleged "unbreakable fasteners." (Photo supplied by Giant Loop, Harold Cecil)
Friends say I'm unrealistically biased positively toward Giant Loop Products. Could be. I own and love several of the company's fine products: the Giant Loop Coyote Saddlebag, Dry Bag, Diablo Tank Bag, Kiger Tank Bag, and the Great Basin Dry Bag. All of that gear is fiercely waterproof, tougher than rhino skin, and brilliantly designed for backwoods motorcycling. When I received a trio of Pronghorn Straps to test, I pretty much assumed this would be another brilliantly designed product that would become an indispensible part of my travel kit. Turned out, that was pretty much a no-brainer assumption.

The three Pronghorn Strap options (Photo supplied by Giant Loop, Harold Cecil)

The first thing I felt needed to be challenged was the claim that the fasteners are "unbreakable." As a retired reliability engineer, I am compelled to test any such claim because I absolutely do not believe such stuff. In the interests of truth and the American Way, I will admit that I received these straps as "media samples," so I had no money invested in the following abuse/tests. Likewise, earlier in my career--when I was paid to abuse/test industrial electronics, music equipment, professional audio equipment, medical devices, software, firmware, and hardware--I did not pay for that equipment, either. Fair is fair.
Practically speaking, what kind of abuse would something like these straps and their buckle expect to experience? First, serious abrasion and tension stress under a variety of temperatures. Second, impact damage from crashes within the same range of temperatures. (For example, 0oC to 40oC.) Finally, an outright attempt to find the breaking point of the strap or buckle, whichever comes first would be typical test engineering experiments. I decided that I would limit my tests to semi-destructive because I wanted to long-term test the straps on our RV excursion during the winter of 2013-14. First, I measured the strap's total pre-test length for a distortion/elasticity baseline (32.1cm).

So, I started with simple abuse. I clamped one of the red straps (the size I thought I was most unlikely to use) to my vise and whaled away with my 4 pound sledge at the buckle and strap for a bit. The buckle showed abrasion signs of abuse afterwards, but it didn't break. The strap looked a bit scratched up, but it didn't appear to be weakened, either. So, I froze (at -5oC) the same strap in my basement storage freezer for a few days while leaving it under tension with an expansion clamp extended far enough that the buckle distorted significantly. After leaving it frozen for a few days, I pulled it out and gave the clamp a few more squeezes which stretched the buckle and strap even more, but didn't break it. Next, I tossed the strap into my wife's food dehydrator (80oC) and left it for a week while she dried pears on the other three trays. (Yeah, I know. I probably poisoned us with the plastic out-gassing. At our age, poisons will have to be pretty aggressive to matter much.) Out of the dryer, I put the strap back into the clamp and stretched it to 125% of it's relaxed length and left it in the clamp for a day. That ended the bench testing phase of my procedure. After that abuse, the 20oC resting length of the strap was 32.23cm, 101% of it's original length. The buckle retained it's original shape, compared to my untested copies. The strap didn't even retain the clamped form and appeared to be returning to the packaged shape after a few days on the bench.

A month later, I used two of the red straps to secure my Giant Loop Dry Bag to my WR250's tail rack for a camping trip along the St. Croix. (So much for my ability to guess which size strap I'd use most often.) One of the two straps was the one I'd abused in my earlier tests. I'd imagined that this trip would be pretty benign because the fall had been wet and I didn't plan on going off-road much between the Cities and Two Harbors, but once I got out of town I ended up letting my GPS guide me northward with the instruction that I waned to avoid freeways, major highways, toll roads with a high preference for dirt roads and "ferries" (in case I ever get a chance to cross the St. Croix on one). Pretty soon, I was bouncing along on a heavily farm-equipment-rutted road enjoying the hell out of my all-time favorite motorcycle. 350 miles later, I was still south of Duluth by 50 miles and looking for a place to hang my hammock for the night. As either a testament to my faith in Giant Loop products or my simplemindedness, I hadn't check my load once in the last 250 miles. It was all there, though. Ten minutes later, I was swinging between two trees reading my eBook with the sound of the river in the background, mosquitoes in the foreground, and birds and bats in between until the light failed and I fell asleep.

A few weeks later, I used five of the Pronghorns to secure bicycles,hardware, and the WR250X to my customized Harbor Freight trailer and we headed south for our first winter in retirement. Somewhere around 6,000 miles into the trip, weather, vibration, and metal fatigue caused one of the brackets I'd used to hold a bicycle in place snapped and a blue Pronghorn strap between the bike ramp and the bicycle's lower frame was all that kept my mountain bike from being abandoned on the highway in New Mexico. I didn't discover the failure until we stopped for the night.

I started collecting information for this review in 2013 and, somehow, the final article ended up sitting in my computer for three years after any formal "testing" ended. I regret that I didn't stay on this because the Pronghorn straps have more than exceeded my expectations and have lived up to their "unbreakable" claim, at least with any semi-normal use. I love 'em.

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