Pivot Cycles' Mach 4 cross-country and marathon racing flagship has undergone a much needed diet for 2011, dropping a substantial 300g. This brings total frame and shock weight down to a much more appropriate 2.5kg (5.5lb).
Pivot president Chris Cocalis says torsional frame stiffness has actually gone up by about 20 percent over what was already a remarkably true-tracking chassis.
Changes to the front triangle include a tapered 1-1/8 to 1-1/2in head tube, a more curvaceous top tube shape borrowed from the longer-travel Firebird, and slimmed-down shock mounts and cable guides.
Out back the updates are even more extensive with newly forged uprights on the rear triangle, a much more dramatically relieved chainstay yoke, and asymmetrical chainstays. The previous version's carbon fibre upper link is retained, along with its wide-format machined aluminium and carbon fibre lower link, and cartridge bearing pivots all around.
Cocalis says changes to the Mach 4's suspension geometry yield a more efficient ride, both in terms of pedalling performance and bump-eating capabilities. Shock stroke shortens compared to the 2010 version.
This makes for slightly higher leverage ratios than before, but the Fox RP23 shock's revamped valving supposedly makes for a more dynamic range of ride characteristics across the ProPedal platform damping adjustment range.
According to Cocalis, the changes will be most noticeable in the higher ProPedal positions where riders will notice similar resistance to bob as before but lower blowoff thresholds when bumps are encountered.
Pivot fit the updated Mach 4 with a shorter-stroke shock than before
Mach 5.7
Last year's Mach 5 trail bike extends its reach a bit for 2011 with a 5mm bump in rear wheel travel and a subsequent name change to the Mach 5.7 (though it's a bit misleading as last year's Mach 5 actually had 5.5in of travel).
The 5.7 drops a sizeable 230g of weight, yet torsional stiffness – and thus handling precision – has been improved by a claimed 20 percent.
The revamped Mach 5.7 has more travel, is more stable at speed and is lighter, too
The most significant updates, however, are the revised frame geometry – which now includes a 10mm lower bottom bracket and slackened head tube for improved high speed stability – and the new rear suspension geometry which is designed to sit a bit further into the travel than before.
Again like the Mach 4, the new Mach 5.7 gains a tapered head tube, a Firebird-like top tube and a revamped rear triangle with forged uprights, heavily machined yokes and asymmetrical chainstays.
The Pivot Mach 5.7 has a newly tapered head tube
Firebird
Updates to the versatile Firebird all-mountain machine are more subtle, including a beefier carbon fibre upper link that more readily accommodates coil-sprung rear shocks – and the more aggressive riding styles that generally accompany them.
There's also a revised front derailleur pivot mechanism that runs quieter than before, the ISCG tab positions have been tweaked, and an improved chainguide system offers better chain retention off the inner ring.
Pivot's do-all Firebird model sports 167mm (6.6in) of travel and versatile geometry
Phoenix DH
Finally, there's the recently introduced Phoenix DH, which uses the same dw-link rear suspension design as the rest of the Pivot Cycles range but with revamped pivot positions to yield 207mm of travel and an overall feel better suited to its World Cup downhill racing intentions.
Frame construction is suitably robust with healthily proportioned aluminium tube sizes throughout plus an especially stout central chassis that houses both the upper and lower links as well as the coil-sprung rear shock. 17mm and 19mm pivot axles plus dual-row cartridge bearings throughout keep flex at a minimum and despite the rear shock's tucked-in positioning, logically placed cutouts and openings still leave all of the adjustments readily accessible.
Pivot's latest Phoenix DH is aimed at full-blown World Cup downhill race courses
Geometry is highly customisable with interchangeable through-axle rear dropouts that allow for tunable wheelbase and bottom bracket height, and the front end will come with a Cane Creek Angleset headset that can provide 2.75 degrees of head tube adjustment.
The Phoenix DH won't be available until January but the rest of the Pivot Cycles collection – which includes the unchanged Mach 429 full-suspension 29er – is in production and available for purchase now.
Pivot again use the dw-link suspension design but in a more gravity-oriented tune
