So day one of Interbike's Dirt Demo 2007, and everybody gets the quick blogs while I go full-bore geek for my fellow egghead fanatics. I'm sunburned like a good Irishman should be spending all day on the surface of Mars, but tomorrow is looking to be pretty damn painful. I'm also completely fried--legs blown out, feet screwed up, and I have to be up in three or four hours to get in line with all the fully shaven guys who're already asleep with their heart rate monitors set out on the nightstand. I spent time on so many bikes today that, by the end, I had to look down to remember what I was riding. I rode a ton of bikes today, though (yes, including a 650b bike), and I'll post as frequently as I can, but considering the depth I have to go into on my blogs, I'll have to beg patience, and hope somebody out there likes getting all the gory details.

You’re looking at the reason I was literally the first person on the first bus to Bootleg Canyon for Dirt Demo this year. The Pivot Mach 4 and Mach 5 bikes are the result of collaboration between Chris Cocalis (the founder of Titus) and Dave Weagle (creator of the patented DW-link suspension system). Having been one of the foundational guys using a Horst-link, Chris has been fine-tuning DW’s system for some time now, and we knew we were going to be riding something very special today. The bikes did not disappoint.

I’ll cut right to the chase: we shouldn’t have ridden these bikes so early in the day, because they set the bar so damn high that nothing else we rode could hit it. These bikes absolutely haul ass. They truly were incredibly supple over even the small stuff, while being arguably the most bob-free bikes we’ve ridden. We’ll get to how they do it in a second, but first, a little about the bikes.

Chris Cocalis likes his bike names clean, simple, and referencing some person or vehicle from the classic Speed-Racer cartoon.

The Mach 4 is a 4” travel bike.

The Mach 5 is a 5" travel bike.
Pretty easy to keep track of, eh? Many sizes will be offered, from XS to XL.
The smallest frames receive shorter 1.5" stroke rear shocks.

King headset fans will wail and moan that the frames look integrated, but word is these frames are compatible with Campy's Hiddenset system, and Cocalis went with it for a reason: lowering bar height. In order to keep bar height low, without shortening your head tube to the point of lousy top tube and down tube approach, Chris felt it necessary to maximize head tube length and tuck the headset inside.

Both frames rode very light, though we have not been able to verify frame weights. We suspect them to be in the 5.5lb and 6lb ranges, respectively, though it’s possible the Mach 4 frame creeps under that 5.5lb mark, as there’s really not a single piece of metal out of place or loitering anywhere in this bike. Both frames used Fox RP23 rear shocks. Pro-pedals are a beautiful thing, but we didn’t need it on these bikes, and that's an even more beautiful thing.

Like all DW-link bikes, both bikes articulate on two sets of very short rockers.

The Pivot's lower DW-link rocker.

The Pivot's upper DW-link rocker.
The stiffness of these frames was noticeable. Instantly visible is the displaced lower portion of the seat tube, which kicks forward and flows into a machined shroud that houses the DW-link's lower rocker. The more XC-oriented Mach 4 uses a single non-drive side strut to tie in the chain stays and seat stays ala a Santa Cruz Blur.

The Mach 5 always uses a heavier duty struts to reinforce the top tube to seat tube juncture. It also uses dual struts to join the foremost portions of the seat stays and chain stays, similar to the Intense and more conventional DW frames.

Close-up of Mach 5 struts with partial detail of derailleur mount and lower link housing.

But, as Cocalis explained, the incorporation of the DW-link was only the beginning. In order to orient the pivot locations exactly where he wanted in order to truly optimize the DW-link configuration, the entire front derailleur position had to be rethought. As any serious frame designer what the worst part of his day is, and he'll tell you: front derailleurs. In order to break free of the constraint of a front derailleur clamp, Cocalis replaced it, instead incorporating a direct mounting system that accepts e-clamp front derailleurs from Shimano (XT and XTR are offered), but doesn't require the e-clamp bottom-bracket plate. Sounds complicated, but it's actually very simple: your front derailleur just bolts into directly into your frame. This is incredibly tough to photograph on a built bike, but you can see it fairly welll here.

The frames also are among the first mountain frames ever to use Shimano's new 92mm bottom-bracket shell and press-in bearings. Finally, something else you get to use your headset press on. Obviously, we've unsure of this stuff--and so is everyone else--but Shimano's pretty conservative about releasing wacky new stuff, so this system has been flogged for a while now, and is already instantly common on many high-end road machines from Trek and Scott. Could is solve the "every external bearing wears faster than old square-tapers" conundrum?


Aluminum fasteners were used throughout, and that lower DW-link was housing a Cocalis trademark: eight sealed cartridge bearings stacked double-row, meaning you might well go years without replacing a bearing in this bike.

Stay tuned for an extended test. We're getting one of these demo bikes for ourselves. If they can steer around trees as well as they stuck to the sandy ledges of Bootleg, a hell of a lot of you are going to want one of these. Production models won't be available until late-Winter or early-Spring.

My only complaint? Wheels were a bit small. But here's a big announcement: that's going to change.