BikeRadar's bikes: building an XC race-rocket test platform

Dave Rome’s SwiftCarbon Detritovore cross-country build

It’s not often I get to a build a bike from scratch with the pure purpose of testing the components that create it. However, that’s exactly what I set out to do in order to continue testing Shimano’s XTR 11-speed group after its initial buildup on a Niner Jet 9 RDO.

With the groupset decided ­– along with matched Tharsis XC handlebar, stem and seatpost from Shimano – the journey started on finding the rest.

Below are the basic details on how the bike came to be complete. Detailed reviews on many of the components listed below are not far away, as I’m already riding the grease out of this build.

The frame: dialled Detritovore

The swiftcarbon detritovore sits bare, waiting to become a bike :
The swiftcarbon detritovore sits bare, waiting to become a bike :

A bare frame sits awaiting the build

Knowing I had an XTR groupset with nothing to bolt it to, the guys at SwiftCarbon happily handed over one of their frames. With a clear intention to create a race bike, Swift arranged a Detritovore (D-Vore) hardtail frame.

Related: Shimano XTR M9000 groupset – first ride

This full-carbon frame hasn’t changed much since we last reviewed it and at 1390g for a medium, it’s not exactly the lightest thing going today. However, given time spent on this and the Evil Twin dual suspension, I knew the geometry was well dialled and that ride quality wouldn’t beat me up on the local Sydney trails.

The fork: fit for the Epic?

It's a name in suspension we don't see a great deal of in australia, but first impressions are positive :
It's a name in suspension we don't see a great deal of in australia, but first impressions are positive :

Something a little different...

Right around the time of arranging the frame, DT Swiss got in touch following an article I’d done on the Cape Epic. I’d made a comment that just about every brand of suspension fork was being pulled apart on a regular basis in order to handle the hellish conditions. The guys at DT Swiss, wanting to prove that their product was up to it, sent out a fork for review.

I received an OPM ODL 100, which features new 2016 SKF seals for reduced friction and improved durability. I also got a Two-In-One handlebar lockout, although this will be fitted once I’ve suitably tested the stock three-position crown-mounted switch.

The drivetrain: creak-free claims

At first i was going to build the bike 2x11, but was forced to ditch the front gears. this was the aftermath :
At first i was going to build the bike 2x11, but was forced to ditch the front gears. this was the aftermath :

Sometimes things don't go as planned... we got as far as trying to connect a cable before realising Shimano does not offer a compatible 11spd front derailleur

This build was initially set to be a 2x11 configuration; however, it quickly became apparent that Shimano does not offer a compatible top-pull E-type front derailleur in XTR 11-speed. Sure, an older 10-speed could be made to work, but it just pushed me sooner toward my end goal – testing XTR in 1x configuration.

Related: Front derailleur types

With this, Shimano didn’t have stock of single-ring chainrings at the time (I’ve now received one), and OneUp had just released its 45t expander cog and M9000 compatible narrow-wide rings. I've been toggling between oval and round rings for the past couple of months, and the weird-looking one is starting to win me over.

With no shims or adaptor spacers needed, this c-bear ceramic bottom bracket converts the pf30 shell for use with a shimano 24mm crank:
With no shims or adaptor spacers needed, this c-bear ceramic bottom bracket converts the pf30 shell for use with a shimano 24mm crank:

Shimano doesn't make any PF30 bottom brackets – quite amazing given just how many frames have gone that way 

Based in Belgium, C-Bear had reached out regarding a humorous article in which I complained of creaking bottom brackets. C-Bear claims its bottom brackets – which do without shims or adaptors – are solution to the common issue. At an ideal time to this build, the brand offered a bottom bracket to be tested. I pressed in the all-metal PF30-Shimano 24mm bottom bracket with a light coating of anti-sieze.

The rolling stock: well rounded if a tad weighty

O.D.L is dt swiss' acronym for its three-position lockout (open-drive-lock) :
O.D.L is dt swiss' acronym for its three-position lockout (open-drive-lock) :

These XTR M9000 wheels are coming toward the end of their testing period

The bike is currently rolling on XTR M9000 Tubeless Race wheels as I complete my long-term testing on these. Next up is a pair of DT Swiss X1501 for review, something that should drop a little weight from the surprisingly weighty XTR wheels.

At the time of receiving the frame, Swift sold the Detritovore as a quick release frame, providing interchangeable 142x12mm dropouts in the box. However, with no thru-axle provided I decided to match it to the fork with a DT Swiss RWS E-type model.

Wrapping these tubeless rims are Specialized Fast Trak Control 2Bliss tyres in a 2.20in width, sealed with Stan's NoTubes sealant. Although now showing plenty of wear, in the past year they’ve proven totally reliable. While not the most traction filled over loose or muddy terrain, they’re well rounded performers for fast-rolling rubber.

The touch points: a mixed bag

There's plenty of carbon on this ride. of course it can still be a lot lighter (not that 9.7kg is heavy), and that's something we aim to achieve over the next few months :
There's plenty of carbon on this ride. of course it can still be a lot lighter (not that 9.7kg is heavy), and that's something we aim to achieve over the next few months :

The handlebar, stem and seatpost are from Shimano's own component brand, PRO

As already mentioned, PRO supplied the contact points when I first received the XTR groupset. These cockpit parts were originally designed for Di2, allowing seamless integration with the wires and battery. While I’m not using electronic components, this has provided a good chance to test the new parts – which share features we’re now seeing in PRO’s other top end offerings.

The PRO Tharsis XC stem is perhaps the most interesting component in that it features a threaded collar enabling external adjustment of headset preload without needing a star nut. The design keeps the steerer empty for a Di2 battery. Sadly, such a feature means you need a 36mm headset spanner to your stem.

The pro tharsis xc stem allows you to keep the steerer tube hollow (room for a di2 battery) - with a homemade rubber protector fitted, everyone can see it's hollow:
The pro tharsis xc stem allows you to keep the steerer tube hollow (room for a di2 battery) - with a homemade rubber protector fitted, everyone can see it's hollow:

A view straight through

Also, the stem's system doesn't play nicely with steerer spacers used on top. So before deciding on handlebar height, I used an expanding compression plug to achieve headset bearing preload. Since then, I've cut the steerer and made a little custom touch in replacing stem's plastic top cap with an anti cookie-cutter rubber sleeve, this way everyone can see the steerer is hollow.

ESI grips are a regular choice of mine, but these are the new contoured model. undecided if i prefer them or not :
ESI grips are a regular choice of mine, but these are the new contoured model. undecided if i prefer them or not :

New ESI Fit XC grips

Comfort points are a mixed bag, and have been selected based on a combination of personal preference and curiosity. I’ve been a long time user of ESI silicone grips and they’re my go-to on my other bikes. They’re lightweight, grippy and comfortable. Recently, ESI released the contour grip, which is designed to relieve pressure from the sensitive nerves in your hand.

The saddle is of course personal, and I’ve recently settled on a Specialized Phenom Pro in a 155mm width, which is far wider than i previously would choose.

Finally, an old personal set of XTR M980 pedals made it to this bike. Beyond a loosening issue I had when the pedals first came out, which resulted in a warranty, these have been ultra reliable and I’ve just about abandoned them in terms of the maintenance.

A weight weenie's breakdown

Model

Weight (g)

Frame

SwiftCarbon Detritovore, medium

1390

Headset

FSA integrated

87

Fork

DT Swiss OPM O.D.L 100, 15mm thru

1585

Front wheel

Shimano XTR M9000 29in, 15mm

760

Rear wheel

Shimano XTR M9000 29in, 142x12mm

880

Brake rotors

Shimano RT-99 160mm

232

Brake rotor lockrings

Shimano alloy

18

Front brake

Shimano XTR M9000

184

Rear brake

Shimano XTR M9000

199

Rear derailleur

Shimano XTR Shadow+ M9000

222

Chain

Shimano M9000

232

Cassette

Shimano XTR M9000, with One-Up 45T expander (328g stock)

392

Bottom bracket

C-bear Ceramic PF30-24mm Shimano, MTB seal

143

Crankset

Shimano XTR M9000, 175mm, OneUp 32T Traction ring

555

Pedals

Shimano XTR M980

308

Front tyre

Specialized Fast Trak Control 2Bliss 29x2.20

641

Rear tyre

Specialized Fast Trak Control 2Bliss 29x2.20

632

Tyre sealant

Stan's sealant

95

Right shifter

Shimano XTR M9000 I-Spec II

106

Handlebar

PRO Tharsis XC Flat, 700mm width

162

Stem

PRO Tharsis XC 80mm

140

Seatpost

PRO Tharsis XC 27.2mm x 400mm Straight

214

Saddle

Specialized Phenom Pro 155mm

208

Seat clamp

PRO Performance

18

Grips

ESI Fit XC

64

Gear housing

Shimano SP-41

28

Inner gear cables

Shimano SUS stainless

12

Bidon cage

Jet Black Carbon Pro

22

Rear axle

DT Swiss RWS E-Thru

70

Total

(Actual weight on Feedback Sports scales is 9.73kg)

9,599

A conclusion that's still TBC

The finished product - a swiftcarbon detritovore built to 2016 standards :
The finished product - a swiftcarbon detritovore built to 2016 standards :

Freshly built, the bike isn't as clean anymore

The build as listed above is how the bike currently sits, covered in crud. It's not the exact build that the bike started as, and it surely won't stay like this for long either. Stay tuned for future individual part reviews – there’s plenty of fast XC riding and associated component testing ahead.And in the meantime, be sure to scroll through the gallery up top.

David Rome

Former Editor, Australia
Dave was the editor of BikeRadar Australia until early 2016.
  • Discipline: Mountain, road and cyclocross
  • Preferred Terrain: Fast and flowing singletrack with the occasional air is the dream. Also happy chasing tarmac bends.
  • Current Bikes: Trek Fuel EX 27.5, SwiftCarbon Detritovore, Salsa Chilli Con Crosso
  • Dream Bike: Custom Independent Fabrications titanium, SRAM Etap and Enve wheels/cockpit
  • Beer of Choice: Gin & tonic
  • Location: Sydney, Australia

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