23 May 2019

Hold onto your nachos, people! Pivot Cycles have gone to town here, producing one of the most desirable cross-country race machines imaginable. Let's take a look at the new Mach 4 SL, which will be our race bike for the Port to Port MTB four-day event.

The not-so-minor details

Product

Pivot Cycles Mach 4 SL

Contact

Price

15999

Weight

10900

Positives

Supremely cutting edge XC tech.

Negatives

Let's talk about the mortgage...


Pass me the chamois cream, it’s time to go racing.

If Pivot Cycles were a race horse, they’d be called Winx. These guys are on a winning streak like you wouldn’t believe, and their recent crop of bikes has been a joy to ride. One area of their line-up that was clearly due for a refresh was in the category of XC racing, and right on cue these Arizonans have delivered a show-stopping whippet.

How crisp is it?

We say right on cue because the official launch date of this bike happens to coincide with one of our favourite Australian events, the Port to Port stage race. The timing was too good, and so we’ve very happily locked the Mach 4SL in for four days of racing.  This sharp looking steed has 100/120mm travel, 29″ wheels, is awash with XTR and carbon, and is way, way faster than our legs!

The Live Valve shock sits in a vertical orientation, at odds with all recent Pivots.

Check out or reviews of the Pivot Firebird 29 and Trail 429 while you’re here!


Lighter and more compact.

How light? 1845g is the claimed frame weight for the Mach 4 SL World Cup (you can add about 200g for the FOX Live Valve equipped Team version we’d assume), putting it right in the mix with the latest crop of carbon race bikes. Scott’s Spark, usually regarded as the lightest dual-suspension going, is around 1750g by way of comparison. The new frame is 300g lighter than its predecessor, the Mach 429SL. While our test bike weighs in at 10.9kg, the super light World Cup XTR version of this bike is said to be well under 10kg.

The Live Valve battery is mounted to the underside of the top tube and it simply clips off. All up, Live Valve adds around 200g to the bike.

Aside from the obvious presence of a battery pack slung beneath the top tube (more on that below), the clearest departure from the usual Pivot design is the orientation of the shock, which runs vertically in front of the seat tube rather than under the top tube. The primary driver here was to facilitate a more compact and lighter main frame, while still preserving room for a full-sized water bottle, even on an X-small size.. Without the need for shock tabs on the top tube, the tube can be made a lot lighter, plus standover height can be reduced too, along with seat tube lengths which allows the use of long-travel dropper posts.

Yes, it gets a dropper too, and a proper one at that – a 125mm FOX Transfer.

Compared to the rather meaty rear ends found on most Pivot duallies, the Mach 4SL is pretty slender out back. There’s no front derailleur mount (phew) which is one factor in allowing the symmetrical, raised chain stay design of the rear triangle, the straight lines of which save more weight than a dropped chain stay shape. We certainly hope that the slim lines of the rear end don’t mean big stiffness compromises, as that’s always been one of our favourite attributes of Pivot bikes.

Looking along the slender chain stay to the tasty Raceface Next SL cranks.

Same DW-Link, just a different layout.

Don’t be fooled into thinking that Pivot have abandoned their allegiance to the DW-Link suspension design. While the suspension layout is different, it’s still a DW-link, delivering 100mm of rear wheel travel. Read our previous reviews of any Pivot and you’ll see that we’re always full of praise for the efficiency and composure under braking afforded by this design. Even in short travel applications like this (perhaps especially so), it’s the quality of suspension travel that matters.

Big hardware and stout linkages help make Pivot bikes go where you want them. Note the neat heat shrink wrap of the brake line and Live Valve wire.

Live Valve, in the flesh!

It’s been almost a full year since the innovative FOX Live Valve system was announced, but there’s been a complete absence of Live Vale equipped bikes on the market up until this point. We’d love to know why, but regardless we’re very excited to finally ride this system in its full consumer-ready format. Pivot Cycles were one of the brands heavily involved with FOX in the development of the electronically controlled suspension adjustment system and the new Mach 4 integrates the sensors, wires and battery of Live Valve neatly.

Here it is! Great to see this stuff finally make it to market.
The fork sensor neatly bolts the arch. So that’s what those little threads are for!

What’s Live Valve?

The potted version is that Live Valve is an electronic system that automatically adjusts the compression settings of your fork and shock in response to terrain that you’re riding. On smoother terrain, it will firm up the compressions settings of your suspension so as to maximise efficiency, but as soon as a bump is detected the suspension opens to allow unrestricted response to the impact. You can control the threshold of bump required to open the suspension too. It does all this in under 3 milliseconds, which is fast enough to just about be undetectable. The system also detects incline/decline too, and will react differently depending on whether you’re climbing or descending.

There’s generous standover height.

The perfect application for Live Valve?

If there’s an ideal application for Live Valve, we think this is it. Over the course of four days of racing, who knows how many times you’d normally reach for your shock’s lock out lever… hundreds, at least. Live Valve does this for you, every time, without you having to think about it.


Make sure you check out our in-depth video analysis of FOX Live Valve here!


The XTR ‘race’ brakes have a very light and easy lever feel.
It’s here, and it’s lovely. The XTR 12-speed groupset shifts like butter.

And is that the new XTR?

The unicorn of mountain bike group sets! XTR 12-speed has hit the market, and it finds its way onto our Mach 4 SL. The shift quality is smoother than shaved legs in silk sheets, and with a 10-51 cassette we’ll have no excuses on the climbs. The cranks, however, are from Raceface, with a Wolf Tooth chain ring. We’re glad to see a 34-tooth ring – on a bike this light and efficient a smaller ring would be too little.

This one goes to 51, baby.

Can we talk about the price?

We’d rather not. It makes us nervous to think about riding around on a bike worth this much cash – what if we crash the damn thing?! Ok, this bike will set you back a whopping $15999. The non-Live Valve version is $12999. Wowsers.

All those little details…

As you’d hope, the little things are all well and truly perfect. From the neat rubber cover that keeps crap out of the lower linkage, the noise-cancelling ‘waves’ chain stay protector, the ideal cable routing, nothing is a millimetre our of place. The dead silence of this bike attests to the attention to detail.

Plenty of room for threading internal cables with a cleanly executed port system.

Setup notes so far.

In order to get the bike how we like it, we’ve flipped the stem and chopped the steerer, as well as fitting our preferred PRO Turnix saddle in place of the WTB Volt. We also went to town with the heat shrink, doing our best to bring order to the extra wires of the Live Valve system. We’ve left the bars at full 760mm width, partly because the funky Pad Lock grip system relies upon a weird wedge shape that’s moulded into the Pivot bars and we can’t be bothered to find another set of 35mm diameter bars to take their place.

A modern race bike. Long gone are the days of 71-degree head angles.
We’re not sure how we feel about Pivot’s Pad Lock bar/grip system.

In terms of the suspension, we followed FOX’s recommendations for the rear shock and it feels great, but we’ve opted for a slightly lower pressure in the fork than the manual would recommend, running two volume reducers in the air spring as well.  We rode multiple laps of the same test track to work out what firmness of Live Valve threshold we liked best, and so far we’re leaning towards the third out of five increments, but we’ll likely make adjustments throughout the race to suit each stage.

Ok, let’s get this thing dirty and keep it upright!