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Mach 4 SL Carbon Team XTR Live Valve Complete Bike
Cross-country riding calls for a whole different science from the traditional all-mountain machines we see dominating the marketplace these days. Instead of the long-low-slack trend that makes your ride feel akin to a Clydesdale, you need a speed machine built to operate with the thrust of a rocket ship fighting its way against gravity, beyond the atmosphere, and out into orbit. And so it takes a careful eye, keen attention to detail, and a different approach to build a beast like Pivot's all-new Mach 4 SL Carbon Team XTR Live Valve Complete Bike. This race-ready steed spins forward with progressive XC geometry that's roots combine the coveted Mach 4 and Mach 429 SL, and a sharp carbon layup that drops a whopping 300-grams off of the previous 429 SL's already feathery stature. But don't let this lightweight demeanor fool you — with steep geometry, 29-inch wagon wheels, and a new vertical shock layout, this space ship is ready to take flight up climbs, and soar down slick roots and chunky rock gardens while you charge your way to the front of the pack. And you don't have to just take our word for it, the bike is already making an immediate splash. How immediate? Woodruff racked up a Short-Track win within 24-hours of its launch, giving us sound proof that its built for speed.
As we've seen throughout the bike industry, the Mach 4 SL takes on the popular trend of longer-slacker, but doesn't go overboard into Trail territory, pulling the head tube out to just 67.5-degrees (paired with a 120mm fork). Compared to the previous 429 SL's 69.3-degree head angle, the Mach 4 SL's head tube will lend the slacker angle to a bit more stability on descents, so you can take on steeper drops, and chunkier rock gardens without your bike feeling noodly under pressure. But this is a cross-country machine after all, and with pedaling being top priority, Pivot's engineers make things steeper in the hind-quarters, moving to a prime perch for power at 73-and-a-half degrees — ideal for speedy power transfers, and staying forward when you're out of the saddle and mashing up steeps.
Speaking of pedaling platform — if you're familiar with Pivot's Mach 4 and 429 SL, you may be looking at the rear triangle with a puzzled gaze, as its shock layout shifts tremendously. While the Mach 4 SL still carries on with the coveted DW-link, Pivot's designers opt for a new vertical shock layout. This allows a more compact frame design that uses less material in order to shed weight, and improved integration for Fox Live Valve (we'll get more into Live Valve later). This new shock layout offers 4-inches of supple suspension, ideal for gobbling up variable trail terrain, and quieting harsh chatter on the straightaways. Much like DW-link applications you've seen before, the vertical layout still offers phenomenal small-bump compliance, keeping your tires glued to the trail for traction control as you soar up climbs, and a plush mid-stroke to take up the impact when you thought you could turn those two rollers into a double, but ended up taking things a little too far, and landing in the flats.
While the new shock is undoubtedly the highlight of the 4 SL's linkage, it's worth noting that it also affords space for a full sized water bottle (even in size extra-small, or two on the extra-large frame), and creates clearance for improved stand-over height, enabling size extra-small to accommodate riders as small as four-foot-ten, with a stand-over even lower than the 27.5-inch Mach 4 of prior seasons.
Pivot employs the XTR Team build with some of its favorite cherry-picked components to put together this rocket ship, including Shimano's latest-and-greatest XTR 12-Speed groupset that stretches beyond the competition, and offers you a gear for absolutely any terrain that might unfold in front of you. A lofty 11 - 51-tooth cassette accommodates sprints for the finish line when every watt matters, and offers a sense of relief when you're pointing it up intensely steep climbs that challenge your sanity. DT Swiss' carbon XRC 1200 hoops keep you rolling quickly, while a 36-tooth star-ratchet Spline hub offers near instant engagement for quick propulsion. To keep a good thing going, Fox's Factory suspension takes care of rowdy terrain, soaking up chunder with buttery-smooth Kashima-coated stanchions — and takes things up a notch with Live Valve integration.
Fox's Live Valve suspension brings electronics in to play, with technology that's been around in automotive racing for years, but has largely remained a foreign concept in mountain biking. To quiet the skeptics, Fox spent three years testing and developing Live Valve before it's launch, making sure reliability and performance were on target. The Live Valve system uses accelerometers on both the fork and the rear triangle to sense impacts and changes in the trail gradient, with a microprocessor (Fox calls it the Controller) mounted near the rear shock, housing a third accelerometer and a rechargeable battery. Using these sensors, the Controller measures terrain at a rate of 1000-times per second, and activates solenoid valves in the fork and shock that open in just three milliseconds, going from firm pedaling platform, to wide open plushness almost instantaneously.
This directly benefits cross-country riding, as it defaults the solenoid valves to the closed position, the equivalent of running your fork and shock in the firm mode, so you get the most out of every pedal stroke. When the system senses an impact, it opens the valves to allow smoother suspension action, improving traction, bump absorption, and overall ride quality. After a preset timer, the valves return to the closed position to regain pedaling efficiency. Each bump resets the timer, so when you're charging through rock gardens, or sustained sections of rough trail, the suspension stays in the open position to better mitigate impacts. The accelerometers also sense when you're going downhill, so if the bike is angled more than 6-degrees downward, both the fork and the shock remain open. When climbing, the Controller will open whichever suspension component feels the impact, and then return to the firm position immediately afterwards, unless another impact is sensed. For that trails, an impact opens both the fork and rear shock, with a delayed timer to account for successive impacts, but not so long to cause the bike to wallow in its travel when you start hammering hard. Should you go airborne, the system opens both the fork and shock to absorb your landing, returning to normal once again when the bike is rolling smoothly.
Fox claims that you can get around 16-to-20-hours of active ride time from a single charge on the Live Valve system, but if you run out of battery while riding the system opens your valves, so you can use all of your travel without a harsh ride. It's important to note that Live Valve only affects the low-speed compression circuit, changing the overall stiffness of your suspension. Rebound settings and air pressures aren't impacted, so you'll want to set your sag and baseline settings in the same manner as a normal air suspension. And if you're skeptical about the Live Valve, or think you might not want to ride with it every day, there's always the option of shutting off the system entirely, rendering your suspension the same as a standard setup.
- Pivot takes XC seriously with its new rocket ship ride
- Steep seat tube angle keeps you perched for the attack
- Take on chunky terrain, and power back to the top with moderate head tube
- Vertical shock layout improves stand-over height, water bottle clearance
- New frame design sheds 300-grams over previous 429 SL
- Fox Live Valve electronically adjusts compression in real time
- Live Valve switches between firm pedaling and open plushness in 3 milliseconds
- Lightweight carbon frame offers stiff control, and a 10-year warranty
- Kit includes DT carbon wheels, and Shimano's new XTR 12-speed drivetrain for lightweight, reliable performance
- Item #PIV1WU3
- Frame Material
- carbon fiber
- Rear Shock
- Fox Factory Live Valve
- Rear Travel
- Fox Factory Stepcast 34, 44mm offset, FIT LIVE
- Front Travel
- Pivot precision sealed integrated cartridge
- Shimano XTR M9100, 12-speed
- Rear Derailleur
- Shimano XTR M9100, 12-speed
- Race Face Next SL
- Chainring Sizes
- Bottom Bracket
- Shimano XTR M9100, 12-speed
- Cassette Range
- 10 - 51t
- Shimano M9100, 12-speed
- Shimano XTR M9100
- Brake Type
- hydraulic disc
- Phoenix Team low-rise, Carbon
- Handlebar Width
- Phoenix Team Padlock
- Phoenix Team XC/Trail
- Stem Length
- Phoenix WTB Pro Volt
- [extra-small] KS Lev Integra, 100mm, [small, medium, large] Fox Transfer, 125mm, [extra-large] Fox Transfer, 150mm
- DT Swiss XRC 1200 Spline
- Spline with 36t star ratchet
- Front Axle
- 15 x 110mm Boost
- Rear Axle
- 12 x 148mm Boost
- Maxxis Ardent Race, TR, EXO
- Tire Size
- 29 x 2.2in
- not included
- Recommended Use
- Manufacturer Warranty
- [frame] 10 years
California Proposition 65
What do you think about this product?
November 26, 2019
You haven't really lived, until you've ridden Live Valve In a world where we have to put up with words like downcountry true XC bikes are becoming few and far between. The Mach 4 SL is Pivot's XC race bike, and it rides like it. It is super efficient, comfortable while seated, and is lively handling bike. I find that people often gravity towards riding "too much bike" for their given terrain. It was refreshing to ride a true XC bike, that was efficient in everyway. It changed the way I rode. I didn't shy away from a steep climb, or from adding in an section of trail to my ride. I found myself riding longer, and farther on such a light, efficient bike. What really shines on this particular bike is Fox Live Valve. Put simply, it works really well. It makes perfect sense that a computer can open and close valves in your suspension infinitely faster than a human being can do. And in practice it matches the suspension to the terrain you're on as quickly as you can ride it. It's such a novel feeling on bike that it can instantly switch the suspension from being open to closed. It actually made my rides more interesting to find some new terrain, or features and see how the Live Valve would react. The most interesting scenario is to come out of a compression and begin pedaling hard on the other side and find that the suspension has already been switched to firm setting. No nobs, no levers, nothing cluttering your handlebars, it just works. In terms of parts specc'd on the build, I'm really happy to see a dropper post on this bike. If world cup XC racers run droppers on their bikes, no reason to miss out on all the convenience and safety that come with a dropper. I'm a little surprised to see a 160 brake rotor in the front, but I guess that's part of the race bike ethos. Pivot builds bikes with amazing attention to detail, that shows out on trail. If you're looking for ultimate performance in an XC bike, the Mach 4 SL is your ride.
November 20, 2019
wish I would have never ridden this bike
- I've used it several times
I am in the process of finalizing a new mtb to build over the winter here and was about decided on the frame. I decided to spend a few weeks on the Mach 4 to compare and now it's thrown a wrench into my thought process. does live valve work, in a nutshell yes, would I love to have it, totally. The extra price does make it tough, but if you can do it, I'd highly recommend it. I have never been fond of a "lock out" button, so many wires off of my bars and adjustments are then limited. with live valve you get it dialed in and hit it hard in the hard pack flats, climbs, berms, bumpy rocks, whatever, you are just good to go. I actually really really got to like it and want it. The mach 4 SL frame is outstanding. very stable in whatever terrain, it's light, climbs well, just a great XC bike which is what I ride. I rode a S and I'm almost 5'7" and thats what I'd race with, it was just a little easier to toss around than a M. Pivot might be considered a boutique brand, and they are but I think they along with Ibis and Yeti are making phenomenal frames. The Mach 4 SL is a real race frame, it's fun to ride in general but it will go fast and handle an XC course superbly. End conclusion, would I own it yes, will I buy it, possibly.
October 7, 2019
Live Valve x Pivot Impresses
- I've used it several times
I'm a skinsuit-wearing, watt-counting, 100mm travel-loving XC nerd with likes his 2.2s, remote lockout, and aero helmet. I prefer a hardtail when I can swing one. The list of XC full-suspension bikes that I like is pretty short, and Santa Cruz's Blur TR currently sits at the top. Because of my obsessive focus on efficient pedaling, I was intrigued by the Live Valve system, and I jumped at the opportunity to demo it. I took 2 primary conclusions away from my week-long demo: 1- Does it work? Yes, mostly. It stiffens up when it's smooth/flat/uphill, and it opens up when it's rough/downhill. I personally wanted it to be stiffer climbing, and more reliably open descending. That said, I'm probably more sensitive than most folks will be. 2-Is it worth the money? For me, not yet. If I'm completely honest, I didn't like Live Valve more than a good lockout system like you get on the Blur TR. It's incredibly impressive, and it actually cashes the checks that it writes when it comes to performance (I'm looking at YOU brain shock,) but at the end of the day, I don't think that this will speed you up in an XC race application, especially if you're limited to a 4-figure budget for your next bike. If you're a non-XC rider who has the patience to dial it in perfectly, and you're not concerned about spending a pretty penny to have the latest and greatest, I can give it my endorsement. I'm excited to see where Fox takes the system in newer iterations. ***Full disclaimer, I did not ride this particular build. Pivot provided an X01 build with Live Valve for test purposes.***
October 4, 2019
Dream XC Bike
- I've used it once or twice and have initial impressions
This is a dream bike for sure, I don't think it gets much better than this for an XC bike. You've got top end parts, great geometry, low weight, and Live Valve! I had a chance to demo this bike and don't think I'd change any of the build parts if I owned it beyond adding a bit more aggressive tire, it's pretty well set up. I didn't try the bike without Live Valve and as it was my first time on this bike it was hard to tell how good it is, but it did seem to help a good bike through rock gardens. I want to try it further but I'd say it's well worth the extra money on a bike of this caliber, I'd upgrade to this over carbon wheels if I had the choice. The geometry of the bike felt great with a 120mm fork, it climbed really really well and felt decently capable. I had a few pedal strikes but a shorter crank would have solved that. I took the bike down a rough trail and there it really reminded be that it's an XC bike, not one of these new "downcountry" rigs, but I still liked it enough that it made me wonder what chunkier tires and a 130mm fork (not recommended by Pivot) would do... Compared the the Santa Cruz Blur Trail which I've also spent time on recently it rode a bit faster and more efficiently I think but felt a bit less capable on rough stuff. Compared to the Niner RKT 9 it rode a bit more like a trail bike - more confident but not quite as good a power transfer. These are real rough first impressions, I didn't have the chance to dial in any of these bikes beyond an initial ride.
May 23, 2019
- I gave it as a gift but have feedback to share
See attached image for Geo numbers - Claimed frame weight XS w/ shock 2,105g (4.64lb) - Claimed weight complete World Cup XTR build in medium is 20.9 lb (9.48 kg) without pedals
May 23, 2019
what size should be recommended for a 5,11 person?
March 12, 2020
what is the weight?