We’ve ridden plenty of trail bikes but this one is configured a little different. The back is the business end with 140mm travel and a fast rolling Maxxis Rekon 2.6 tire, while the front is the party with 160mm travel and an aggressive Minion DHF.
We started the test session on the Mag 7 trails of Moab and the bike revealed its fun, pump track side. The bike was playful and easy to throw around, as it is low to the ground and loves to dance and change direction. The big rear tire has a lot of traction and it may seem hard to break free, but throw that rear around and get that bike in the air and the bike comes out to play.
Climbing was quite a delight, too, as this 28 pounder took on all rock steps and steep slabs the trail had to offer. There was so much traction in Moab with these big tires that we just had to remind ourselves to keep the power on and pedal. We had a few pedal strikes with our thick flat pedals, but moving forward on the saddle unweighted the rear enough to lift the BB and enhance the anti-squat properties of the suspension.
And as you will see on the photos, descending on this bike is truly confidence inspiring. We never pushed it hard enough to break front traction but we definitely pushed the limit on the descent of the Portal Trail. There were so many steeps with varying exits from smooth roll outs to two foot drops. Not knowing the line, we slowly gained confidence to trust the bike and let the Fox 36 take care of the shenanigans up front. The fork stayed high in its travel on the steeps and took the big hits when needed. It really is a high compliment to say that this bike made the Portal Trail manageable for a first time rider.
Why the odd head and seat angles?
A quick look at the geometry chart reveals a seat angle of 73.5 and head angle of 66.5. We initially wondered why they didn’t go with a more current 74-degree seat angle and then we remembered that this bike was originally designed with a 150mm fork in mind. In testing, Pivot front man Chris Cocalis and the design team discovered that they enjoyed the bike much more with a 160mm fork. Thus that’s what the bike is spec’d with and a side effect is the geometry numbers were altered a bit.
It’s good to see that test riding vetoed the targeted geometry spec sheets in this case. But if one wants to configure this bike with a 150mm fork, it will work, delivering a 74-degree seat tube angle, 67-degree headtube angle, and slightly lower BB height.
How does it fit in the Pivot line?
Here’s how the Mach 5.5 slots in the Pivot line-up that is admittedly getting a bit crowded.
- Switchblade – Fox 36 29er with 150mm front, 135mm rear
- Mach 5.5 – Fox 36 27.5 with 160mm front, 140mm rear
- Mach 6 – Fox 36 27.5 with 160mm front, 155mm rear
- Firebird – Fox 36 27.5 with 170mm front, 170mm rear
The Mach 6 is due for an update very soon so it will be interesting where it will slot in this tight line-up. We would love to see the Mach 6 relaunched with around 160mm travel but with 29er wheels to really complement the Pivot armada.
Why no SuperBoost 157 rear hub?
One of the most fascinating and controversial aspects of the Pivot Switchblade bike introduced last year was the use of a SuperBoost 157 hub instead of the popular Boost 148. For the Switchblade, Pivot felt they needed to allow tires up to 3.2, and a front derailleur on very short 29er chainstays. This is the reason they chose to employ the 157mm hub spacing. They achieved all these goals but the consumer is left with a one-off wheel solution, incompatible with the rest of the wheels and cranks in the garage.
On the Mach 5.5, the tire requirement is only up to 2.6 so Pivot chose not to use SuperBoost 157. The lateral stiffness of the rear end matches that of the Switchblade in their tests, when applying test load on the smaller diameter wheel, and the consumer is left with a much better solution because Boost 148 wheels are quickly becoming the most widely available. Cranks are also readily available from many brands. As a result, Pivot is able to immediately make frameset only purchases available, unlike the Switchblade.
How does it compare to a Switchblade?
The Switchblade is 135mm/150mm 29er travel while the Mach 5.5 is 140mm/160mm 27.5. So at each one’s core, they’re fairly different bikes. The Switchblade is a 29er that is one of the best of its kind with very short stays and a laterally stiff rear end. It can also double as a plus bike that can handle up to 3.2 tires. The Mach 5.5 in its native form sports 2.6 tires with very similar geometry to the Switchblade. It can also handle tires down to a 2.35 size making it quicker and more agile.
When the Switchblade is in my personal favorite form, with 2.8 Plus tires on 27.5 wheels, it is very similar to the Mach 5.5, as their dimensions are very close to each other. They are both very stiff laterally and have useable suspensions going down or up. The key is they can evolve to distinct bikes and expand their sweet spot in opposite ends.
At its core, the Mach 5.5 is a little bit quicker and rowdier than the Switchblade. Downhill and on jumps and singletrack, the Mach 5.5 is going to be a little more playful and easier to throw around. The Switchblade, meanwhile, will eat up miles of terrain more willingly. The prospect of 2.6 tires on 29er wheels is a very interesting proposition too that can make the Switchblade more attractive.
The Mach 5.5 Carbon is another winner from Pivot. With its stock 2.6 tire spec, it is a burly trail bike, ready to take on all that Moab has to offer. Play around with tires and you’ll have a light, fast, agile bike.