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Dirt Rag Articles
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Tester: Karl Rosengarth
Age: 52
Height: 5' 10"
Weight: 150lbs.
Inseam: 32"
Vital Stats
Country of Origin: Taiwan
Price: $3700
Weight: 27.5lbs. w/o pedals
Sizes available: XS, S, M (tested), L, XL
Contact: www.pivotcycles.com
The 140mm-travel Mach 5 is Pivot's vision of the proverbial "jack of all trades" mountain bike. Pivot's head honcho, Chris Cocalis, described his approach to the Mach 5: "The whole idea of the bike is that it has neutral handling, not overly slow nor overly quick. Some of the newer 140mm bikes fall more toward a 'freeride-light.' But the Mach 5 falls more toward our cross-country based bikes. It has all the capabilities, but at the same time has the pedal feel that somebody would feel comfortable doing an endurance event or 24-hour race on this style bike." I totally get the idea of having "one bike that does it all" and was anxious to evaluate how well the Mach 5 fared in the pursuit of that lofty goal.
To kick off this test, Chris Cocalis stopped by Dirt Rag HQ to talk tech, and join the staff on a group ride. Chris gave us a primer on the dw-link rear suspension that Pivot uses on their bikes. The brainchild of Dave Weagle, the dw-link is a version of a dual-link suspension, where there is an upper and a lower linkage. According to Chris, a key benefit of any dual-link bike is that the wheel travel path doesn't have to be one constant arc, it can be an S- or a V-shape, something other than an arc. The Pivot suspension has a rearward wheel travel path in the first part of the travel, designed to produce better square-edged bump performance and allow the suspension to roll through the smaller trail junk a lot easier.
Dave Weagle's "anti-squat" patent is unique in that it covers the rider's center of mass, and how it sits in relation to the suspension. Chris explained: "When you bear down or shift your body weight to pedal, that is really the most dominant force on the bike." While some suspension designs rely on compression damping to counteract rider-induced bob, the dw-link negates bob via careful placement of the pivots. According to Chris: "The whole idea when I'm working on designs with Dave is that for a given size of bike, I'll give him a range of rider saddle heights that would fit that given size, what stem length we're going to spec and even which riser bar, and he'll calculate a center of mass. He'll do all the anti-squat calculations on where we need to finally move those pivots so that rider mass shift doesn't load the suspension up."
My test bike was a 2010 model and it had the new high-volume Fox RP23 rear shock with Boost Valve technology. Instead of having one level of compression damping over the entire stroke, the Boost Valve allows softer damping in the first 60% of the stroke and firmer damping in the final 40%. The idea is to enhance plushness, while keeping the bike from feeling wallowy. My Mach 5 came with Pivot's entry-level Shimano XT/SLX build kit ($3700). Pivot also offers the Mach 5 with a Shimano XT kit for $4400, an XTR kit for $6000 and a SRAM XX kit for $6700. A frame with rear shock (which weighs in right around 6lbs.) will set you back $2000.
Tech talk is all good and necessary, but the proof's in the pedaling; pedaling the Mach 5 over rough trails, I was immediately impressed with the plushness of the rear suspension. With the rear shock set up with the recommended 30% sag, the rear end responded to every impact, no matter how small. The feeling was all active, all the time. When the bumps got bigger, the suspension never missed a beat. After repeatedly romping through rock gardens, I came away convinced that I've not ridden a more supple-feeling bike than the Mach 5. The suspension masterfully gobbled up square-edged bumps, just as advertised. The rear wheel moved seamlessly through its full travel range, with no quirks nor harsh ramp-up at the end of the stroke. Quite the contrary. The term "bottomless" comes to mind when attempting to sum up the rear suspension. Up front, the Fox Float R 32 (15mm QR) with 140mm of travel matched the coosh and travel of the rear suspension perfectly, giving the Mach 5 a balanced feeling fore to aft.
Despite the cooshy suspension, the Mach 5 felt firm at the pedals. I never had the urge to switch on the rear shock's ProPedal. For the sake of thorough reportage I did occasionally try the ProPedal, just to feel the difference. My conclusion: leave it switched off! Don't bugger up this supple, active suspension with compression damping that's designed for bikes that need help fighting bob. Even on climbs, I preferred having the suspension working full-time, helping my rear tire bear down and stay connected with the trail. Though I didn't have the opportunity to race atop the Mach 5, I could totally see myself rocking this bike in an endurance race. It pedaled that well.
The Mach 5 frame had a tight, solid feel. I never detected a hint of lateral frame flex nor slop in the pivot points. That's not by accident. Pivot puts a lot of focus on frame stiffness. The lower linkage has eight cartridge bearings in it, double the normal count of four. With no pivots out back, the rear triangle (swingarm) is inherently stiff. Pivot and Shimano developed a 92mm-wide bottom bracket size that has a larger-than-standard shell diameter and utilizes press-in XTR bearings. With the wider BB shell, the downtube can be larger and the pivots can be wider—making those items stiffer as well. The lower yoke that goes to the rear triangle is a cold forged part. Then Pivot CNC machines the entire back and insides out of the forging to make a shell from it, and welds plates on the bottom to produce a very lightweight but strong box-section part with no openings in it. The outside diameter of the head tube is very close to the size of a 1.5" head tube. This allows Pivot to use bigger tubes coming into the head tube, resulting in better front-end stiffness. Building a bicycle frame with the aforementioned attention to detail requires a close collaboration between Pivot and their Taiwanese frame-maker. For an inside look at how Pivots are built, see the accompanying sidebar.
On paper, the 22.3" effective top tube on my medium frame seemed a skosh short, but after I threw a leg over the saddle, my rider position fell comfortably in between aggressive and upright [Ed Notes: after this review went to print, I was reminded by Pivot that the effective top tube is actually 23.2" and not 22.3" which is right in line with what I'd expect for a medium frame, and which explains why the bike fit me comfortably. I apologize to Pivot and to our readers for my error in the print version of this article.] With its 69° head angle, handling on the Mach 5 felt decidedly neutral. What we have here is a bike with an even-handed demeanor that's well-suited to its "do it all" philosophy. It took me but one ride to get comfortable and in sync with the bike. After that, I was fine hitting small jumps, busting wheelie drops, and bunny hopping downed logs. The Mach 5 begged to play on technical trail features, and I was happy to oblige.
Though its handling was not "racer fast," the Mach 5 swooped through curvy singletrack without feeling overmatched by tight corners. This is a 140mm-travel bike with singletrack manners on par with 120mm-travel bikes. Its geometry was quite comfortable on climbs, with the only issue coming on the very steepest of grades, where I had to exaggerate my forward lean to keep the fork from wandering. But that's a minor issue in the greater scheme of things. With its predictable nature and ample travel, the Mach 5 was quite capable of bombing downhills, and I had a blast whenever the trail sloped downward. To be sure, there are 140mm bikes with slacker angles that would score a slight edge in downhill-friendly handling. But, I find that slacker bikes tend to feel sloppy in the singletrack and on the climbs. I'm all about the "all-arounder" design of this bike.
The Mach 5 has a lot going for it: an incredibly plush suspension, great pedal feel, all-arounder geometry, and a stiff, well-made frame. No single bike can be all things to all people, but If I had to pick "one bike to do it all" I'd feel confident in choosing the Mach 5.
| Exclusive Dirt Rag Web-Only Extras For Pivot Mach 5 | Chris Cocalis, the man behind Pivot Cycles, recently visited Dirt Rag headquarters. Before we treated Chris to the fine mountain bike trails out our backdoor, we sat down with him and talked about the Mach 5 review bike that we had just received, and about Pivot Cycles in general. Read the interview here.
Read Karl's test blog on the Pivot Mach 5 at this link. |
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| Comment from Clint on 2010-04-19 |
| I love my Mach 5 as well! I put a Talas 150 fork on it and I think it really improved the downhill capabilities. Setting it at 130 (or 110 for ultra steep pitches) is a huge climbing benefit as well.
I've been wanting a full suspension 29er for a long time, so I just ordered a Mach 429. I'm really looking forward to riding both and making a comparison.
Bottom line is that I think Pivots are the best-made full suspension bikes on the market. I have not found any bike that is as laterally as stiff and as plush yet efficient. And I've ridden a lot of full suspension bikes over the years. |
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| Comment from Bob Crow on 2010-01-16 |
| Karl, you really need to throw a leg over the Pivot Mach IV..you will be completely surprised how well this bike handles the tighest XC race courses and still has the ability to bomb some serious downhill..I have had many bikes and the Pivot Mach IV still makes me smile more and more each time I ride. Hope you get a chance to do a test ride it. Cheers, Bob |
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| Comment from Karl Rosengarth on 2010-01-16 |
| Bob,
I don't think I'd be surprised at all ;-)
-Karl |
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| Comment from Allan on 2009-12-28 |
| I love my Mach 5!! I built it up late this past summer and have never had a bike that is as versatile as this bike. I have 2 different fork and wheel combos that allow me to run it at either 69 or 67.5 degree head angles which really adds to it's all around performance. It's the best bike that I have ever owned or ridden. Good review, spot on Karl! |
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| Comment from Karl Rosengarth on 2009-12-24 |
| Jeff, the Mach 5 is very much a fun bike. I had a blast testing it.
I haven't ridden the Firebird, but looks like it would totally rock on burly, technical trails.
Thanks for reading. |
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| Comment from Jeff (Mo0se) on 2009-12-22 |
| Cool write up Karl! Looks like a fun bike... I have wanted to try one of those since their debut. The Firebird looks interesting too. Cheers. Jeff |
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