Pivot Cycles Vault Review: Hidden Treasure – Spencer Harding | The Radavist | A group of individuals who share a love of cycling and the outdoors.

Pivot Cycles’ Vault gravel bike has plenty of amazing tech securely (wink wink) stashed in the frame making for a comfortable and uncompromising riding experience. Spencer is ever chasing something other than geometry inflation to review and Pivot’s patented ISO FLEX technology caught his eye. Make sure you take a peek inside the Vault for all the hidden treasure below…

Quick Hits:

Sizes XS-XL (~46 cm – 59 cm)
Colors: Firebrick Red (pictured), Deep Metallic Blue
Tire Clearance: 700x45c or 650×2.0”
Frame: Full carbon featuring proprietary hollow core internal molding technology
Frame weight: 998 grams
Complete bike weight (XL): 19 lb 15 oz
GRX build as reviewed: $5800
Frame Price: $2900

Pivot bikes ain’t cheap, there’s no way around that. I reviewed the lowest price build of the Vault and it’s still nearly $6K. Pivot is uncompromising in their manufacturing and build spec on bikes so don’t expect anything cheaper from them. After seeing their quality control and how much goes into each frame before it goes out the door, I can say I’m impressed and it all makes more sense. On that note, Josh lives nearby their HQ and is exploring the option of a full factory visit, so watch this space…

I reviewed a size XL which is around 59 cm if you go by the ole’ seat tube measurement. With a modern silhouette and the DNA of a traditional square-frame road bike geometry, the Vault establishes itself on the speed-aligned end of the gravel spectrum. While the seat tube and top tube measurements aren’t an exact match on the XL they are quite close. Id feel safe saying my XL review bike felt like a more traditional road bike geometry, but that isn’t the case for all the sizes. The Vault in sizes; small, large, and XL all have top tube and seat tube measurements within ~10mm of difference, keeping that traditional silhouette, while the size medium and XS frames are the largest departure from that traditional esque geometry. We also see the XS getting a starkly steeper seat tube and head tube angle with both being nearly 2 degrees steeper than the XL as we traverse the size range.

I truly love the deep red sparkle finish on the Vault. Pivot has reduced the size of its branding from past years and made everything more subtle so the sparkle finish can shine through.

My review bike came specced with 700x40c Maxxis Rambler tires, but the frame can accommodate up to 700x45c. I found the stock tires on the small side for my local gravel rides; I use a 38c tire on my “road bike” for reference. With clearance up to 45c, the Vault should have adequate tire clearance for most gravel riders and racers nonetheless.

Frame Details:

Patented ISO FLEX Technology fits 27.2 or 30.9 seat posts and isolates the seat post from the frame
Internal cable routing for all lines including stealth-style dropper posts via Pivot’s silent Cable Port System
Hidden fender mounts
BB386EVO bottom bracket
1x or 2x with integrated front derailleur mount
Dropped seat stays for tire, crank, and chainring clearance

ISO FLEX

The elephant in the room so to speak on the Vault is the ISO FLEX system. The oversized section at the seat tube junction houses the ISO FLEX, a rubber and fiber-reinforced nylon insert. The insert separates the seatpost from the frame and acts as a buffer between the two. This allows the post to flex within the frame and absorb vibrations. The ISO FLEX insert is only available in one density so one’s experience may differ depending on the amount of exposed seatpost (leverage) and your weight. I had 6″ of exposed seatpost and weighed 185 lb and I didn’t find the elastomer too squishy.

Isolating the frame and seatpost allows for the Vault frame to be uncomprising in its ability to transfer power while allowing greater rider comfort. Each advantage is not hindered by the other. We’ve seen similar design intentions in Specialized’s STR system and Trek’s ISO Speed system. These systems all seek to allow the seatpost to move independently of the frame without truly suspending the frame. I’ll delve more into the ISO FLEX system when I talk about the ride feel further in the article.

The insert comes in two sizes, 27.2 and 30.9, depending on your preferred seatpost or dropper post diameter. The 30.9 size opens a larger world of dropper posts (glares at Travis). While the provided Pivot 27.2 carbon seatpost will flex and complement the system, dropper post users can still benefit from the ISO FLEX technology.

Silent Cable Port System

The internal routing uses Pivot’s silent Cable Port System to keep routing easy and quiet. The system uses bolt-on port covers to keep tension on the housing and hoses on either end of the internal routing. This keeps rattling to a minimum, but Pivot still uses foam wrap to further decrease any possibility of rattling. From Di2 batteries to dropper posts, there is an appropriate port if you need it and a cover if you don’t.

BB386EVO Bottom Bracket

What in tarnation bottom bracket evolution did you just say to me? I’m gonna let the company jargon from Pivot handle this one:

“The Vault frame features the BB386EVO bottom bracket system (designed by our own Chris Cocalis). This maximum size BB greatly increases torsional rigidity and strength and improves power transfer for a more efficient ride.”

From what I can divine from an hour of Googling, the 86 refers to the 86.5mm bottom bracket shell width combined with the 30 mm crank spindle diameter. All of this allows Pivot to avoid adding aluminum to their frames as needed for a threaded BB, saving weight and hassle. The 86.5 mm shell also allows the bearings to be wider apart and thus handle stress and load more effectively. Boom—bigger, better, lighter, smoother! If you do need to run a 24 mm spindled crank they can be easily adapted to the 30 mm system.

Dropped Seatstays

While an eyesore for some, the dropped chainstays allow the Vault to maximize crank/chainring and tire clearance while maintaining a stout bottom bracket junction. And if you are wondering why the the non-driveside chainstay is also dropped? This allows clearance for crank-arm-based power meters, a niche for most but tech that can be important for racers. All of this also keeps the chainstays short and snappy at 420 mm. I don’t mind the look of dropped chainstays, personally, and love the ride feel of a short chainstay so I’ll take them.

Save the Double Chainring

The Vault is designed to accommodate any gravel or road 2x drivetrain on the market, cable or wireless. Since this bike leans hard into the speed-oriented side of the gravel spectrum, Pivot has tirelessly engineered the Vault so you don’t have to feel like you’re compromising by using a 1x setup if you really want a 2x drivetrain. I enjoyed my 1x review bike, but for those who need the extra gearing, the Vault has you covered.

Mounts and Mounts

The frame has “hidden” fender mounts for those rainy days. By hidden they are simply on the inboard side of the seat stays and fork to keep lines clean for those sunnier days. Seems like the perfect bike to get some carbon fenders for!

The frame features two bottle cage mounts in the main triangle, with the down tube being a 3-pack mount, and a gas tank mount on the top tube. Unfortunately, the down tube 3-pack mount—if used with a cargo cage—would interfere with using the seat tube bottle mount. I’m told the lower bottle mount is a bit of a holdover from when the Vault was a cyclocross bike, which allowed riders to mount a bottle as low as possible in the frame for shouldering the bike. The lower mounting position allows for a lower bottle and weight but at the expense of using a seat tube-mounted bottle and cage.

Bifurcation of the Gravel World

John already waxed poetic about this in his Mason Bokeh 3.0 review recently, but we are seeing two classes of gravel bikes emerge. On one side, you see bikes with taller head tubes, mountain bike tires, and rack mounts. On the other side, you see what John and I would call a “road bike with big tires.” The Pivot Vault definitely falls into the latter category. I’m not gonna try and buzzword my way into naming these categories, but we stand on the precipice of calling these bikes something more specific than “gravel.”

How Does It Ride?

The Pivot Vault rides like the incredibly efficient and well-designed race bike that it is. I even flipped my stem because, after a few rides, the bike felt like it wanted me more over the bars and pushing harder. Freed from compliance concerns due to the ISO FLEX insert the massive bottom bracket does what it was designed to do, optimize power transfer. In short, the Vault does not flinch when you put weight into the pedals.

While the ISO FLEX insert is less active than the Specialized STR system I reviewed last year, it is a welcome addition to the Vault. Combined with the engineered flex of the Pivot 27.2 seatpost, it creates a smooth ride that my sit bones appreciated. The flex is very minute and mostly imperceptible except in a deep and seated sprint. On rougher roads, the ISO FLEX kept my sit bones happy but made the lack of suspension or damping in the cockpit of the bike more stark. This is where I could rant about wanting bigger tires, but I promised Pivot I would meet the bike where it’s at.

The Vault wants you bent over the bars and pedaling hard. With the bars higher for the general comfort of my lower back, the bike felt lacking. I flipped the stem to lower the bars and the bike immediately felt more at home. If you are used to traditional road bike fit, then you will probably also feel at home on the Pivot Vault.

Since I found the spec undergunned for my personal gravel exploits, I turned to the next best thing: mixed surface rides. (I’m going to avoid being a few trends behind by saying “all-road” here.) Having the Vault in my stable has inspired me to seek out the short and sweet gravel sections in town. The Catalina foothills surrounding Tucson are rife with short unpaved sections of road that are a blast on the Vault. I’ve been scheming and am now up to about a 60-mile ride from my doorstep that avoids major roads and hits as much gravel as possible while barely leaving the city limits. This mixed riding is where the Vault shines in my eyes. It keeps all the snappiness of a road bike and combines it with larger tires. When things get rough, the ISO FLEX helps smooth the chatter without comprising the feeling of a solid frame while you sprint for that county line sign.

As John put it, “All road bikes are gravel bikes, yet not all gravel bikes are road bikes.” If you are coming from a road riding background and you want a bike that is uncompromising in its performance but happens to have larger tires, then the Vault may be just what you are looking for. And, I’d wager that all but the most discerning sprinters could benefit from the comfort the ISO FLEX imbues into the ride.

Parts Spec

The Vault I reviewed is Pivot’s least expensive build for the Vault which means it’s still quite high-end. The new Shimano 12-speed mechanical GRX is as good as you could hope. Having Shimano produce a wide-range MTB-sized cassette to complement their gravel groupset is a no-brainer. The GRX hood shape and brake lever feel are as good as ever. Josh already dug into the nitty gritty of all the options if you are curious.

Pivot specs their own branded seatpost, stem, and headset for the Vault. While the stem and seatpost look a bit clunky, I still want to praise them. I’ve been meaning to pen an op-ed about how I haaaaate the ever-shrinking bolt head size on bike fasteners. Say what you will about the Pivot branded components, but each uses an M5 bolt with 5 mm hex tooling on the head of the bolts—a mechanic’s delight. It speaks volumes when a company as weight-obsessed as Pivot can spec larger bolts on their own components. The seatpost especially is designed to complement the ISO FLEX technology, offering an intentional amount of additional compliance.

The DT Swiss CR 1600 wheels felt bland but gave me no issue whatsoever. The Easton EA bars were too narrow (46 cm) for my preference but had a nice flair and would feel spacious to anyone coming from riding a road bike. With en vogue drop handlebars trending toward sub 36 cm, my opinion will seemingly continue to hold less and less water in this arena.

The stock Maxxis Rambler 700x40c tires have minimal tread that didn’t make too much noise on pavement but still held their own off road. While smaller than I’d like, they had EXO sidewalls that withstood all my riding flawlessly. I could see this bike truly singing with some more supple and slightly larger tires…my mind wanders to an Ultradynamic Cava or something of the like.

Wrapping Up

The Vault is the best road bike I’ve ever ridden. It just happens to have larger tires and be labeled as a gravel bike. Years ago I said the same thing about the first Salsa Cutthroat, which by all measures is many times less a road bike than the Vault. It’s been exciting and inspiring for me to throw my leg over such a pedaling machine.

The ISO FLEX system offers a welcome relief to bumpy roads, paved and unpaved alike. The system is simple and nonmechanical; adding comfort without a great deal of complexity or maintenance.

Admittedly, I initially wanted to take the build in a whole other direction: flat bars, 650b wheels, and a dropper post. That bike would have been fun, but that’s not the point. I said I would meet the Vault where it was and I’m happy that I did. It has inspired me to find rides that fit between my road bike and my rigid MTB “gravel” bike.