The Switchblade is more like a Swiss Army Knife. This 135-millimeter-travel carbon machine can run 29-inch tires up to 2.5 inches wide, or 27.5+ tires up to 3.25-inches wide–with or without a front derailleur. Most impressively, the chassis manages all that with stubby, 428-mil stays.
That was a lot of numbers. Here's another one that explains how Pivot pulled it off: 157. That's the width of the rear-end spacing on this bike. Yep, 148 wasn't enough for Pivot, so they built the Switchblade around a rear-end width and chainline more commonly seen on DH bikes, and called it–and we're pretty sure there's a hint of satire here–'Super Boost Plus.' Existing 157 hubs will fit the Switchblade, but, in the name of stiffness, the wheels that come stock are custom-made with wider flange spacing equivalent to a 148 hub.
The Switchblade accounts for the change from 29 to plus-size wheels with a 17-millimeter-stack lower headset cup, an intelligent way to keep the geometry consistent, while other brands ask users to adjust fork travel. The bike ships with the cup installed, and we initially left it in while testing the bike as a 29er, which puts the head angle at roughly 66 degrees. With this setup, the Switchblade has a confident stance punctuated by a 460- mil reach and an 1,190-millimeter-long wheelbase.
The frame feels stout, but ironically the carbon Reynolds wheels Pivot sent with our bike pushed the stiffness to the point of discomfort and unpredictability. Pulling the 17-mil cup makes for friendly climbing geometry, but the Switchblade didn't inspire us to stomp on the pedals like some other mid-travel 29ers, instead preferring a seated, take-it-as-it-comes approach.
When descending, the chassis corroborated the intentions of the 150-mil Fox 36 fork, pushing us to charge technical sections with abandon. The combination of the big wheels, stiff frame and DW-link suspension was unfazed by the roots and rocks on our mid-travel loop, leaving one tester to remark that "It feels like a 135-millimeter all-mountain bike." In this respect, the Switchblade has carved out its own niche as a mid-travel 29er that can rumble with the big rigs without the sluggishness of a true heavyweight.
Q&A with Chris Cocalis, President/CEO – Pivot Cycles
Who is the Switchblade for?
The Switchblade is really for any rider looking to improve their capabilities on the bike and have more fun. In 29" form it's fun and capable and we feel that because of what we were able to achieve with the shorter chainstay length in this category, it handles a wider variety of terrain better than other bikes in the class. It gives all the benefits of a longer travel 29er but climbs and manuals better. It's just a more versatile machine for a wide range of trail riding and enduro riding. In the 27.5+ form, not only is it incredibly fun but its confidence building. The traction is incredible going up and down. For expert riders, it opens up new opportunities for technical riding. For the average or novice rider, it can enable them to ride more technical terrain with confidence.
The Switchblade is in a class of its own in several ways, but especially in terms of stiffness. Combined with the Reynolds wheels, we felt in many situations that it was actually overly stiff, causing us to have difficulty holding a line. Maybe we're just a bunch of twinkle-toed tea sippers. What's Pivot's philosophy on stiffness? Is more always more?
We are definitely NOT on the side of the fence that believes more stiffness is always better. Chassis flex in the right places is very important to a bike riding right and it's something that has been a huge part of everything I've worked on since the early 90's. When we talk about stiffness for the Switchblade, it's all relative. We have targets for bottom bracket stiffness, head tube torsional stiffness, rear triangle side to side stiffness, and rear triangle torsional stiffness measured from the top of the wheel and the bottom of the wheel. The challenge with a long reach bike that has short chainstays and big tire clearance is actually getting stiffness numbers high enough. So, when we talk about the Switchblade's great stiffness, it means that we were able to hit our targets and we are very pleased with the overall chassis balance. Within our range of full suspension bikes, the Switchblade falls right in the middle of our line.
In this same issue, your team tested the Firebird. The Firebird is the stiffest frame in our entire line-up due to the size of the tubes and the strength/impact requirements for this category. It was actually quite a development process as we needed to reduce the stiffness of that frame from where we started. The Firebird is a long travel bike for very aggressive riding. We designed it to be a pro level enduro/park bike so we are comfortable having a chassis that is a little more rigid. The Switchblade needs to cover a wider spectrum of use and the chassis balance reflects that.
This would normally be the part where I agree with your twinkle-toed tea sippers assessment of yourselves. However, the wheel stiffness is a big deal on the Switchblade and that is certainly what you could be experiencing. We have the test data from the development of the Super Boost Plus 157mm rear hub and its pretty staggering. With a 29" alloy DT 25mm inner width rim using DT Competition 2.0 butted spokes, the 142mm spacing is the baseline. A 148mm rear spacing provides a 16% stiffness increase at the rim. This is good improvement on an alloy rim, but a really strong rider can still feel some wind up or flex in a 29" wheel. The SB+ 157mm wheel is 46% stiffer than the 142 hub (30% stiffer than the 148). These are big numbers and when combined with a wide carbon enduro rim, the stiffness numbers are really high. Interestingly, the front 110mm boost wheel stiffness numbers and the rear SB+ 157mm wheel stiffness numbers are very similar so it makes for a good balance of wheels stiffness front and back.
With the Switchblade, riders can run really light alloy wheels and still have great wheel stiffness or they can run carbon and be even stiffer. It is really up to rider preference. That said, I really considered you guys as more of a beer drinking crowd. The tea thing is interesting. I'll leave it at that.
Our test bike arrived with a OneUp Cog installed on the cassette. Are completes now shipping with 11-46 XT cassettes?
Yes, they are now shipping with 11-46 cassettes for Shimano builds.
Threaded bottom brackets are universally appreciated amongst our editors, and we were glad to see several brands move in that direction this year. What benefit do riders get from the press fit design on the Switchblade?
Regarding press fit in general, we take a strong engineering-based stance on why we use press fit. This design has served us well as it continues to give us more space to work with and allows for wider pivot placement, and larger down tube cross sections for a stiffer, stronger, and lighter frame. Executed properly, it also offers better control over the chain line, improved bearing alignment and supports the bearings better. Of course the design also allows us to mold a full carbon frame without bonding in an aluminum BB shell. This is one of the main reasons why it has become the industry standard for carbon frames.
From a carbon frame design standpoint, it is superior. However, it does require very tight tolerances which Pivot is able to hold. Unfortunately, not all companies and factories are as precise and it can lead to problems. It's interesting, however, as a threaded shell that is not done correctly has its own issues that lead to creaking BBs, bearings that are not well aligned, drivelines that are not straight and chain-lines that are out of spec. Both threaded and press fit BB’s are excellent designs if executed properly and installed properly as well. In the case of Pivot, we run tighter tolerances than most in the industry and the press fit design allows us to build a better bike overall.
From a purely engineering design standpoint, a threaded BB on a carbon frame requires the frame to basically have a open through hole with about the same amount of carbon supporting it and tolerance as the press fit design. Then the manufacturer needs to bond in a threaded BB shell. This machined shell usually has a separate left and right side and the parts mate with each other. These parts can be mis-aligned with each other, and the bond can creak and come loose over time. It's a round shell inside a round hole so there is no mechanical lock between the two, other than the bonding area. It works fine most of the time, but (in general) it is still the highest warranty failure area for manufacturers running threaded shells in their carbon frames. Even if that was perfect, the frame is now heavier and it has a narrower threaded shell bonded inside the frame so that you can now have bearing cups. The bearing is pressed inside the cup with threads hanging off the cups that screw into the bonded shell inside the frame (even reading it sounds strange). These cups hang outside the frame, and are leveraged outside the frame which leads to higher stress loads on the cups, bearing, and threads, plus…it's heavier.
If your car or motorcycle were made this way, it would weigh twice and much and be less reliable. It's ok to put bearings directly inside the linkage, inside your hubs and even in your headset, so why doesn't it make sense to do it inside your BB? Well, it does make sense. It just needs to be done correctly, with the right tolerance, the right installation procedure and the right BB design as well.
Anything you'd like to add?
Thanks for including us in your Bible of Bike Tests issue. We are stoked to be a part of it and I look forward to checking out some of those trails in the future. The test location looked really cool.