The Mach 4 is also a bike we (and many happy customers) have had the pleasure of riding all across the country on every type of terrain imaginable. It’s been ridden hard on our own National Trail, traversed the technical rock and root strewn trails of western Pennsylvania, powered through the forests of Northern Wisconsin, and Minnesota, as well as tackling Fruita, Colorado and just about everything Moab has to offer including Porcupine Rim - right alongside riders with 6” travel bikes.

For those not buying into the notion that more travel is always better, the Mach 4 could be considered your ultimate trail bike as well as being one of the fastest, most efficient race bikes on the planet.

The Tech:
So what is it that gives the Mach 4 this amazing combination of pure race performance while also being a fantastic all around bike?

There are more than a few things that go into the Pivot Mach 4 that set it apart making it truly unique in the 4” travel class. First and foremost, we designed a bike that is firm and responsive under pedaling, in or out of the saddle. The DW Link suspension design, custom shock tuning, and Pivot suspension rates all combine to make for a bike that is a rocket in or out of the saddle, and when climbing or sprinting. One of the primary benefits of the DW Link suspension design is position sensitive anti-squat. Put simply, The DW Link is the first and only suspension design that takes into account the rider’s weight and position on the bike (i.e. the rider’s center of mass). When you stand up to sprint or shift your weight back to climb, your weight is the dominant force on the suspension. This bob or “squat” caused by the rider’s mass shift is a good part of the reason why Propedal, SPV, Brain, lockouts, and a host of various other “platform damping” solutions exist to resist suspension bob and squat. With the DW Link’s anti-squat design, the dual suspension links are positioned in such a way that your weight shifts do not result in unwanted suspension movement or “squat” under power. This allows us to tune the rear shock with lighter valving so the bike is free to absorb bumps and follow the terrain better. We combine this with a slightly rearward travel path through the beginning 1/3rd of the travel to give the Mach 4 incredible square edge bump performance and increased traction on climbs. The combination of Pivot’s suspension rates and the DW Link’s anti-squat properties to give the Mach 4 incredible pedaling performance, zero hesitation on acceleration, and that lively snappy feel that a discriminating cross country racer demands. At the same time, there are very few if any true pro level XC bikes that actually get 4” of travel at the rear wheel. For most XC race bikes, “4 inches” is a number at the brochure, not at the rear wheel. This is certainly not the case with the Mach 4. Real, usable, controlled travel is another reason why the Mach 4 can go fast and maintain control in technical terrain that will completely overwhelm the suspension on other cross country bikes.

While we were busy designing the best performing suspension in the world, we decided that the rest of the frame needed to set a new bar as well. The Mach 4 is a well thought out machine from tip to tail. This is not a bike where new technology has been used simply for the sake of technology. Better stiffness, better shifting, easier set up, longevity, and a host of other performance criteria were addressed. A lot has been said in the press about our 92mm wide bottom bracket, eight cartridge bearing DW Link, direct mount front derailleur, and obsession with frame stiffness. All these things add up to a better bike that will last longer and perform at a higher level. Most riders don’t realize the amount of flex that occurs in other bikes. This flex translates immediately into lost energy and high wear on the suspension Pivots. With all the work we put into the suspension to make sure that none of your power is lost to suspension bob, or squat, we certainly want to make sure that it isn’t wasted on flex either. I don’t know about you, but I don’t want my bike to flex! The Mach 4 relies on large, thin wall hydro-formed tubes, hollow 3D forgings, wide oversize pivots, and the highest quality suspension bearing pivot design to make sure that every last bit of your energy goes into allowing you to go faster, ride more efficiently, and have more fun.

Weight:
This deserves to be addressed separately because it tops the list of frequently asked questions and having a light bike is certainly in the top 3 of important items when deciding what and how to build your next cross country race bike. Incidentally, we believe the number one goal a racer should consider is getting the bike that you can go fastest on, which in most cases is not going to be the absolute lightest bike. A rider shopping purely by the scale is overlooking the balance of stiffness, efficiency, and lightweight that will result in the fastest lap times, and here’s why:

First, there are no big secrets among those who know how to build cutting edge aluminum and carbon fiber frames. Most high-end suspension bike frames have a front and rear triangle, a linkage, a shock, usually four pivot points, and all the basic parts that make a bike frame a bike frame. The top builders all use similar cutting edge materials with similar properties. That said, we always find it interesting when a company claims a frame weight under 5lbs for their cross country suspension frame. It’s certainly possible and in a couple of rare cases it has been achieved. If a (medium) suspension frame weighs under about 5.25lbs, compromises in stiffness, longevity, and efficiency have been made to get there. In most cases it is a “target” number and not the real thing. In the case of the Mach 4, this frame was designed with the finished product in mind. The Mach 4 ultimately is designed to be a high performance, lightweight “complete bike”. The future is not looking at just the frame, but the bike as a whole. With the Mach 4, the future has arrived early (it’s that fast). We were not shooting for the lightest frame, but we did design the Mach 4 to be are one of the lightest bikes in the world. There are quite a few areas where we “added” to our frame in order to build a lighter and/or better performing bike. For instance, the direct mount front derailleur tabs are part of our frame design but eliminate the need for a front derailleur clamp. In this case, the difference between an XT standard clamp front derailleur and our direct mount is 35 grams or 1.2oz. The same can be said for our 92mm BB design and larger diameter head tube for the bike’s zero stack headset. Our frames come complete with the XTR bearings as part of the frame and the zero stack headset weighs less then a standard headset resulting in a lighter overall system weight.

In order to prove our point, we decided to enlist the help of Over the Edge Sports in Fruita Colorado to do a little research.

They weighted 2 popular frames in addition to ours on their digital scale. The first being the Santa Cruz Blur XC and the 2nd being the Ibis Mojo. Both frames were approximately equivalent in size and top tube length to our Medium Mach 4. The Blur XC weighed 5.65lbs and the Mojo Weighed 5.9. The Mach 4 weighed 6.1 lbs including the XTR bottom bracket. This is where it gets interesting. If you add an XT front derailleur, XTR bottom bracket, and 11/8th headset to the Blur and Mojo, and then add the direct mount XT front derailleur and zero stack headset to the Mach 4, (a true apples to apples comparison) here is what you get:

• Santa Cruz Blur XC with headset, XT front derailleur, and XTR BB: 6lb8oz
• Pivot Mach 4 w/ headset, XT front derailleur, and XTR internal BB: 6lb9oz
• Ibis Mojo Carbon with headset, XT front derailleur, and XTR BB: 6lb11oz

All three of these are top level performers and all three line up within 2oz of each other.

To further prove our point, we offer our Mach 4 as a complete bike with some very light high performance components from the finest manufactures in the world with the intent of building a race bike that can be raced and ridden virtually everywhere; even by a 200lb rider. The result is a bike that comes in under 21.5lbs in a medium and 21.26lbs as a small. Yes, we said 21.26lbs REAL WEIGHT! This means the Mach 4 comes in lighter then the new carbon fiber wonders from Specialized and Trek (at about the same price) in a package that is far more usable for the real world rider. That said; if you choose, your Mach 4 could be built even lighter! Our lightest stock model uses standard tires with tubes, stainless steel rotors, an average weight saddle, post and handlebar, a Ritchey headset, XTR shifters and derailleurs. By going with just a few of the items that are the rage among the most weight conscious racers, the Mach 4 could push under the 20lb. mark. We haven’t gone off the deep end just yet, but we are sure it won’t be long before one of our customers sends us a photo of their 19.8lb Mach 4. It’s bound to happen.

For those with less of an appetite for high dollar helium hardware, our personal bikes and race team bikes with our standard Fox forks and Fox rear shock are coming in between 22.5 and 23.25lbs. We think that’s just right.

Other frequently asked questions:

• Seat post size: All pivot frames use a 30.9mm post. For reference if you are coming off a Specialized or Santa Cruz and are switching parts over, they use a 30.9mm post as well
• Front derailleur: We use the term direct mount, but Shimano now has two direct mount options. If you are getting a frame, then you will need to order en E-type front derailleur. This is a standard front derailleur from Shimano. In order to install the E-type on your Pivot, all you need to do is remove Shimano’s “e” plate with one screw and it will bolt right up.

• Headset: The headset on the Mach 4 is an 1.125 Zero Stack, also called a 50mm zero stack (because that is the recommended size of the outside of the headtube), Some companies might call it a Zero Stack for 44mm, which refers to the inner diameter “ID” of the headtube. These are all the same item and almost every headset manufacturer offers high end versions of this headset. Even Chris King will be offering this option later in the year. It is a press in, non-integrated headset that allows us to make the bike with a larger diameter headtube, reduce the overall front end height of the bike, while building a stronger frame, and reducing overall bike weight.

• Shock Specifications: For those looking to try something different on their Mach 4, we like to provide the shock and hardware specifications. We do a ton of testing on these frames and feel that the set up we provide is the best, but we understand and support a riders need to test and try different things. For this reason, we want to make it easy on our customers by designing the frames with standard shock lengths and readily available hardware. The Mach 4 XX-Small and X-Small size frame use a 6.5” length X 1.5” stroke. The Small through X-Large frame use a 7.5” length X 2” stroke. All bikes use 8mm hardware and the spacer width is .86” (22mm) and 1.4173”(36mm).

• Sag setting: By design, the Mach 4 (and all Pivots) do not bob/squat under power. Other designs are not this way and thus racers have learned that the best way to get their suspension bike to pedal better is to run less sag. The Mach 4 is a different breed. We recommend 30% sag and highly recommend that if you are going to cheat, then run too much sag and not to little. The bike will pedal the same with 20%, 30%, or 40% sag. However, if you run less then 30%, you won’t get full travel and the bike will feel like the front end is too steep. It will affect bump performance as well. Run at 30% and you will be a faster, happier racer. For the XX-Small and X-Small size frame, run .45” (11.5mm) of sag. For the Small through X-Large frames, run .6” (15.25mm) of sag.

• Why Propedal?: One of the questions we get a fair amount of is the reason for running a Propedal shock on the Mach 4 if the suspension is designed so that it does not require it. First, the RP23 is Fox’s top of the line performance shock and we like to give our customers only the best. Next, we have worked with Fox extensively to valve the RP23 so that the shock will offer a high level of versatility and tuning capabilities for the individual rider. Most riders will run the Propedal in the off almost 100% of the time, but there are racing situations and riders weights where the 3 Propedal options provide a nice benefit. The valving and settings we offer provide progressively stiffer pedaling options (more of a locked out feel), but with a very clean transition to an “open” setting.

• Fork choice 100 or 120: All sizes of the Mach 4 were designed around a 100mm travel fork other then the XX-Small which is designed around an 80mm fork. We have riders asking us if they can run a 120mm on their bike. This is not an issue. It will not affect the warranty and the bike will ride nice with a 120mm. It will slow down the handling a little, but still provide the rider with faster, more reactive steering then our Mach 5. For many riders in the Mid West and Eastern United States, this makes for a nice trail bike set up. For those riders on the XX-Small frame, you can go up to a 100mm travel fork, with a small affect on stand over clearance and front end height.

• Bottom Bracket design and options: The press in BB design on the Mach 4 was designed in conjunction with Shimano. It is an XTR bottom bracket that is lighter and supports the bearings better then the standard thread in designs. The bottom bracket carries a three year warranty from Shimano and comes installed as part of your new frame. If you ever need to replace it, it is easily removed and replaced with the same ease as replacing a headset. This is a standard Shimano part and FSA offers a replacement bottom bracket as well with ceramic bearings. The FSA unit does not weight any less then the XTR BB, but is comes with red anodized cups. SRAM will also be offering a BB to fit this standard for 2010. Pivot is the innovator of this system, but you can be assured that it is quickly becoming the high end standard for others to follow.