New Pivot Phoenix is proof we shouldn't overlook downhill bikes

Downhill mountain biking (DH) might be niche, and brands may only sell a handful of their very specific bikes, but I believe bikes such as the new Pivot Phoenix underline why their design and development are so important.

We’ve watched the Phoenix evolve over the last two years, at first under Pivot's headline rider and team owner, Bernard Kerr, who has had his fair share of success aboard it.

With CNC-machined lugs, carbon tubes, a high pivot and two chains, the Phoenix prototype was a thing to behold and caused quite the stir in the pits.

After all that research and development time, Pivot has now launched the new Phoenix. It may lack some of those prototype elements that garnered all the attention early on, but the full-carbon frame shares the key aspects of that full-factory machine.

There’s 210mm of travel delivered via Pivot’s ‘mid-high pivot’, six-bar dw-link suspension system, a dual-chain drive system, plus adjustable geometry and suspension kinematics.

Downhill-optimised suspension performance

The new frame isn’t built using the time-consuming, expensive to produce CNC alloy lugs (rumour has it, these took something like 90 hours of machine time to produce) and carbon tubes.

It is carbon, however, and shares the same shape and suspension layout as the prototype steeds the Pivot Factory race team have been riding.

Like the prototype bike, the new Phoenix is designed to run mixed wheels as standard.

Pivot refers to the main pivot placement on the new Phoenix as ‘mid-high’. The idea here is to create a rearward axle path, enabling the suspension to more competently swallow square-edge hits.

According to the graphs, the rear axle moves back around 22mm when it’s about 140mm into its 210mm of travel.

From that point, it continues to arc forwards and upwards until bottom-out, finishing at around 15mm behind its starting point.

This is all controlled via Dave Weagle’s six-bar dw-link suspension system, which gives the brand masses of control over every element of the suspension kinematics.

Both the anti-squat (how much the bike resists pedal bob) and anti-rise (a measure to counteract load transfer under braking, preventing the shock extending/rising) are said to have been tailored to ensure the Phoenix remains reactive and responsive when you put the power down, and stays stable and controlled under braking when tackling a steep, technical descent.

A flip chip at the base of the shock enables riders to change the level of progressivity, too, switching between 46.6 per cent (progressive setting) and 39.6 per cent (linear setting) when measured across the full 210mm travel range.

Two chains are better than one… apparently

The most striking feature of the Phoenix is the dual-chain drive system.

This sees a short chain running from the crankset and chainring to a large sprocket that sits higher up, close to the main pivot location. Pivot says adding tension to this short chain is a very simple and easy process.

While we’re used to seeing high-pivot bikes route chains up and over an idler (to help mitigate pedal kickback – something common with a suspension design such as this), they tend to use one long chain, rather than two.

Pivot has taken this approach for a number of reasons. For a start, the chainline can be made smoother, limiting friction/drag.

You also get better chain wrap, which helps with chain retention and boosts durability, as well as creating more clearance thanks to being able to run a smaller main chainring. Pivot says the gearing used is the equivalent of a 37t chainring on a regular system.

That extra clearance is a real plus when you’re close to fully bottoming out the rear suspension in a pile of rocks and could be the make or break of a race run.

Making it fit like a glove

Pivot offers the Phoenix in four frame sizes (S1–S4), with reaches ranging from 435mm all the way up to 515mm.

Each frame size uses a different carbon layup, better tuning it to the size of rider (the smaller sizes will offer a little more compliance for lighter riders, while bigger riders will get a stiffer frame).

Thanks to their reach-adjust headsets, though, you can increase or decrease these measurements by 5mm either way to better suit your needs.

All frames have the same length seat tube (410mm), so it really is all about finding the right length bike for you.

The head angle is suitably slack for high-speed stability, at 62.5 degrees (in the low setting). This can be steepened to 62.93 degrees by using the flip chip located in the seatstay pivot, as well as raising the bottom bracket by 6mm (from 349mm to 355mm).

Wheelbases range from 1,253mm (S1) to 1,333mm (S4), while the rear centre is the same across all sizes at 443mm (but remember, this will grow in length due to the rearward axle path).

Stack height remains the same at 635mm across all sizes, too.

Why does downhill bike design matter?

My take on it is pretty simple. These bikes are designed to operate at the very extremes of what we consider possible on a mountain bike, with particular focus being put on geometry and suspension performance.

Yes, they need to be pedalled, but not in the same way as an enduro bike, so there are fewer compromises being made when it comes to suspension design.

Downhill bike development is a great place for brands to learn from what’s possible, both in terms of construction but also outright performance.

From here, they can adapt and refine in order to transfer these valuable lessons into other types of mountain bike, knowing full well where the limits lie and how to stay within them.

And while some things may be applicable to other bike designs, some won’t be – there’s no chance you’ll be running a dual-chain on a cross-country bike any time soon. That’s okay, though, because work in downhill is what helps to define those uses and design parameters.

While Pivot’s Phoenix project is a great example of the above, let’s not forget the likes of Specialized and the unreleased Demo (could that help to inspire the next-generation Enduro?) as well as what the Atherton bike brand has achieved thanks to its additive manufacturing process.