Bend in the Road: Discs are almost there

After putting in a few hundred miles on a handful of different road disc bikes, I’ve gone from ‘eh’, to ‘meh’, to ‘okay, yeah’. But Shimano or SRAM need to tick two more boxes to make me a full convert.

One, I want be able to adjust how my brakes feel. More specifically, I want to be able to dial in the free-stroke adjust, so the brakes engage just where I want them to as I squeeze the levers.

And two, I don’t want disc brakes to squeal like wounded hyenas under heavy braking.

Both Shimano and SRAM have decent explanations about both of these things, and we’ll get into that a bit below. But as a rider, frankly, I don’t care; I just want it to work the way I want it to work.

Dialed-in feel

If you got on my bike, it would feel a little funny to you, just as your bike would feel strange to me. Neither is wrong, they are just set up to our sizing and preferences. With rim brakes, we can easily adjust how the brakes feel with a simple twist of a barrel adjuster or a tweak of the quick release. With disc brakes, the situation is the same as the brakes on your car; it is what it is.

Now, with my car, I have never thought once about adjusting the where the pedal engages as I press it down. But my car isn’t my bike. I want that sucker to feel perfect, with the brakes engaging just where I want them to, whether I’m bombing into a tight corner or just toodling around town.

SRAM does not have free-stroke adjust on its Hydro R levers. Shimano technically has 1cm of free-stroke adjust, but honestly I can’t feel a substantial difference, and this adjustment is there primarily to balance out the feel left to right, and compensate for the longer hydraulic hose of the back brake.

There are still conflicting views on rotor size, depending on application and manufacturer. matching the right amount of braking power to the rider is key, but shouldn't the bike companies sort this out for us?:

Road disc rotors are powerful and dependable. They can also be noisy

SRAM does, however, have free-stroke adjust on its new Guide mountain bike brakes.

“People who want it to feel really heavy, can dial up pad-contact adjust to get that quick engagement, and those who like a little more play can get that,” said Nate Newton, SRAM’s road technical rep. “The thing is, most people would never ever adjust that. There definitely is a subset who want that adjustability. But what I have found doing demos is that most people will jump on a bike and just ride it. If I ask people how they like their brakes to be set up, they usually have opinions. But it doesn’t seem to come up unless I push the issue.”


In my experience, road discs are quiet most of the time if set up properly. But I want them to be quiet all of the time. Simple as that.

Riding here in Boulder, Colorado, there is one section of road where I can usually get rotors to howl with heat build-up, and that’s coming down Sunshine Canyon, a nine-mile stretch of road that averages about eight percent but tilts to 23 percent, with some sharp switchbacks that require hard braking over about 3,220ft (980m) of elevation change. I weigh about 185lb (84kg), and going from 50mph to 20mph a few times in quick secession does the trick to get the rotors chirping. Outside of that, though, I haven’t had any problems.

This weekend the Rapha Gentlemen’s Race in Colorado provided an excellent test course for disc brakes, with 13,000ft of descending over 107 miles, some of it on loose dirt, and some of it on steep pavement. The only spot I was able to get Shimano R785 140mm rotors to howl was that same spot on Sunshine.

For Shimano, pairing the appropriate braking technology with the bike and rider is everything, said company spokesman and former ProTour mechanic Nick Legan.

“Braking is always a function of traction. Good descenders do late, hard braking, biasing the front brake, then backing off into the corner. But you have to pair braking power with the traction you have,” Legan said, adding that a heavy downhill bike with substantial rubber and full suspension can keep traction more easily than a light road bike with skinny tires.

Going to a bigger rotor (160mm) up front, and perhaps in the back as well, would likely eliminate the heat-induced squeal, Legan said.

This could indeed be a fix, but I want to brake companies and bike companies to sort this out, not me. Perhaps bikes 56cm and larger get the 160mm front rotor, and 54cm and smaller go 140mm?

Another smaller noise issue —?the levers rattling over rough roads when not grasped —?was fixed with a solution courtesy of our US tech editor, James Huang. Since hydraulic brakes don’t have cable tension pulling the levers taut, both Shimano and SRAM levers can rattle. On smooth pavement there is no problem. On rough roads, if you keep your fingers touching the levers, there is no problem. On rough roads when you ride with your hands loosely on the tops, however, there is a definite rattle. James showed me how to put a piece of padded tape inside the lever; problem solved. But again, this should be solved at the manufacturer level, not the rider/tinkerer level.

Hydraulic brake levers rattle. james huang showed me this fix, putting a slice of clear, padded tape on the silver cylindrical bumper above the lever head:

A little rubber bumper on the silver, cylindrical bumper addressed the lever rattle

When it comes to disc road brakes, Shimano and SRAM certainly aren’t, um, stopping. Expect to see more and more of the things —?and hopefully, more and more improved versions of the things —?as we roll into the near future.

“There is a reason that every wheeled sport has gone to disc brakes,” Legan said. “They’re better than rim brakes, period.”

Perhaps. But I want a quiet, customizable experience before I go all in.

Pivot’s redesigned Mach 4 Carbon is brand’s lightest full-suspension frame ever

TEMPE, Az. (BRAIN) — Pivot has updated its long-standing Mach 4 Carbon mountain bike with 27.5-inch wheels, a new geometry, longer travel and a lightened frame that includes integration for Shimano’s XTR Di2 electronic drivetrain. The new Mach 4 Carbon is the fourth generation of one of the brand’s most popular models.

Trek urban, recreation and kids’ bikes for 2015

Trek has launched several new bikes recently, including the 10lb Emonda, the women’s Silque road bike and an updated Fuel EX range. There’s also new and updated bikes in the? family, urban and utility ranges, as shown at the Trek World Australia event recently.

For 2015, Trek will offer plenty of fresh colours, some smart electronic integration, more children’s options and some new tourers.

Urban bikes

The FX series is a staple of Trek’s range, and is built for fitness riding, combining city-bike comfort with road-bike speed. The top-end models (options TBA), including the 7.7FX, have a new ISO-speed equipped carbon frame – similar to that of the popular Domane – for greater comfort.

More basic models continue with aluminium frames, but all receive Duotrap S compatibility, an add-on, semi-integrated speed and cadence sensor that is both Bluetooth 4.0 and ANT+ compatible.

Much of the urban and fitness range is now compatible with the duotrap s system. a wireless speed/cadence sensor that is both bluetooth and ant+ compatible :

Many of the bikes now feature Duotrap S compatibility for speed and cadence tracking

The DS (Dual Sport) hybrid series continues with 700c wheels, front suspension and disc brakes on most models. These bikes are ready for off-road paths as well as city riding.

The 8.6 DS is one that caught our eye. It has a fancy polished look, Shimano hydraulic disc brakes, Shimano SLX gearing and handlebar operated hydraulic suspension lockout. All DS and Neko (the women’s version) models have Duotrap S compatibility too.

The headlight beams from the head tube and the lights are controlled by buttons underneath the top tube:

The Lync features integrated lights

The Lync is an all-new urban bike with integrated rechargeable lights. The god father of mountain biking – Gary Fisher – liked that this series simplifies the process of buying a bike, in that it’s just ready to roll.

The bike features built-in lights front and rear, which run off a central USB rechargeable battery. The front light is in the head tube, while the rear lights are placed at the dropouts on both sides, so they don’t end up being covered by pannier bags. The buttons for the lights are underneath the top tube, and the battery clips into the down tube. Other features include Bontrager’s new Blendr stem dock for fitting smart-phones or similar, and full-coverage mudguards at both ends.

Introduced last year, the CrossRip continues as a commuter built for speed. The dropbar, disc brake equipped series is ready for a range of riding from fast commuting to long road rides, or, if you swap out the tyres, off-road riding or cyclocros.

The Adventure series has grown for 2015. The steel-framed 520 continues, and there are also new models that serve specific purposes in the booming touring market, including the 920 Disc and 720 Disc models. The 920 Disc is built as an off-road tourer, with an aluminium frame and carbon fork, drop bars, large 29in tyres, SRAM 2×10 mountain gearing and sturdy racks front and rear. Similar to the 520, the 920 Disc has bar-end mounted shifters in the form of SRAM 500 TT units.

Lightweight road touring is booming, and for that trek has the 720 disc. the disc braked aluminium frame and carbon fork is designed to offer the handling and speed of a road bike, but with lightweight touring capability:

The 720 Disc is a new lightweight road tourer – the production front bag straps look nothing like those pictured

The 720 Disc is the road-focused equivalent, and has traditional road geometry and a lightweight aluminium frame. It’s built for fast-paced road touring. It features a new lightweight dry-bag system that places waterproof bags on either side of the fork.

This Shimano 105 equipped model features standard road shifters matted to TRP HY/RD disc brakes.

The chelsea 9 is a stylish urban bike for women. it offers basic 9-speed gearing, a solid basket and even a carry handle in the frame for geting up stairs. this model will retail for au$899:

The Chelsea 9

Trek calls its new Chelsea range a “sexy mashup of style and function”. This neat women’s bike features a carrying bar in the centre of the frame, along with a sturdy basket on the front, with a U-lock holder. For the men there is the District models, which offer a similar style-infused bike that looks ready for urban utility. All models have disc brakes and simple rear-only shifting.

Entry-level mountain bikes

Originally highlighted in our Trek Fuel EX preview, Trek is moving its entry-level models to what it’s calling ‘Smart Wheel Size’. Simply put, if you ride an extra-small or small frame size you get 27.5in (650b) wheels, while medium and larger sizes get 29in wheels. It certainly simplifies the ‘which wheel size’ decision.

The x-caliber 7 is a bike we tested previously and loved. for au$999 it has plenty to offer and looks even better than the model we tested: Bold

The Trek X-Caliber 7 gets a RockShox front fork

The X-Caliber, a bike we rate highly, has had its range reduced in favour of more expansive Marlin options. On the women’s side of things, the Cali range is also reduced to make way for more Skye options. ?

26in wheels aren’t totally dead yet – they still appear on the most basic (and cheapest) Skye 26 and 3500 Disc models.

Kids’ bikes

The krx is a road bike for the young ones. based on the madone aluminium series, this 26

The new 26in wheeled KRX

The new KRX is a small road race bike with an aluminium frame, based on the adults’ Madone. It’s recommended for ages 10 to 12 and has 26in wheels with 1in wide tyres, cantilever brakes and Shimano Sora gearing. It looks ready for the crit track.

The girls get one too, in the form of the neko. both the dual sport and neko will sell for au$569:

The Neko is a girls’ hybrid bike, aimed at ages 8 to 12

There’s also now a Dual Sport for kids 8-12 years old, featuring 26in wheels (adults get 700C) and disc brakes – this little rigid hybrid could be perfect if you’re looking for a speedier kids’ bike than the usual suspended mountain bike option. The girls’ Neko is a smaller version of the adults’ Dual Sport bike.

Click through our gallery above for a more in-depth look into the Trek 2015 range.

Shimano offers streamlined disc brake mounting for road bikes

OSAKA, Japan (BRAIN) — Shimano is looking to help bike manufacturers streamline the use of disc brakes on road bikes by introducing a new, more direct mounting standard. Shimano calls it Flat Mount and it seems to be inspired by the recent popularity of direct-mount rim brakes and other integration on road bikes in the name of reduced weight and a more streamlined, aerodynamic appearance. A spokesman said Shimano developed the new mount in collaboration with “s everal large OEMs …

Niner introduces new cyclocross bike

FT. COLLINS, Colo. (BRAIN) — Niner Bikes is launching a new cyclocross model, the BSB 9 RDO, which joins the RLT 9 as the mountain bike brand’s second drop-bar bike.

Saracen Mantra Pro review

The Mantra Pro is the second cheapest of Saracen’s Mantra line, and sits alongside the Zen and Kili ranges as part of the company’s trail hardtail line-up. At a penny under ?600, is it all the hardtail you need?

Frame and equipment: smoothly does it

The frame offers a very upgradeable balance of kick, float and functional features like bolted cable guides and down tube mudguard mounts.

The Schwalbe Rapid Rob might be a bit trade iffy when it comes to root and rock control, the the trade-off for that is fast, smooth rolling flattery of the Mantra’s 13.6kg mass. A chunkier, softer compound front tyre such as Schwalbe’s Nobby Nic or Hans Dampf Evo would significantly increase the Mantra Pro’s confidence on sketchy terrain, so see if you can barter an upgrade if you buy this. ?

The rudimentary 120mm travel Suntour fork is better controlled than most units for the money and has better longevity than most bargain spring sticks, while the Shimano brakes are basic but reliable. They took a little time to bed in, although their reliability and spares availability is assured.

Sure, there are grippier tyres and smoother forks to be had, but all hardtails impose a rattling rear end limit on how much you can exploit the best equipment. Overall, Saracen has done a great job on spec for a small UK-based company.

Ride and handling: agile but not for ascents

The Saracen Mantra Pro is a lot of fun to ride. Once the initially-wooden Shimano discs brakes warmed up, we were able to make full use of the sorted 68-degree steering angle, 70mm stem and 720mm bars to whip and hip the Mantra Pro through the trees with minimal compromise.

With a steep seat angle naturally pushing forward onto the front wheel for extra grip and a seat you can slam all the way down we found ourselves in an ideal position to make the most of what we had and simply ignore what we haven’t.

The geometry exploits the increased smoothness and traction of 650b wheels without losing the spark that makes a trail hardtail fun. A steep seat angle and short stem create a relatively short reach to the bars, which is great for enhanced agility but it’s not so good a position for slogging up long hills fast. You could go wider on the bars for extra leverage but we realise that might freak more recreational riders out.

This article was originally published in What Mountain Bike magazine, available on Apple Newsstand and Zinio.

GT Grade endurance bike launched

First things first: GT doesn’t want you to call the GT Grade a gravel racer, as the carbon-framed disc road bike is more versatile than that.

Compared to a standard road race machine, the Grade’s geometry leans far more towards an endurance or sportive bike; it’s a little taller at the front, a little longer in its wheelbase (as you’d expect from a disc bike), a little lower at the bottom bracket and a little shorter in terms of top tube and reach. Rounding out the geometry to assist with rough-road riding, the head angle is slightly slackened.

GT arrived at what the company calls ‘all-day’ geometry using GURU’s fit system data, as GT and GURU share the same parent company, CSG.

GT has been away from the higher end of road for a while now, but the brand historically had a deep road legacy. From 1996’s US Olympic bikes which pioneered? clever aerodynamics, to the sponsorship of Lotto with Ti Edge bikes to later US teams JellyBelly and Saturn.

The GT Grade bike has been in development for three years. Initially the team at GT had identified a trend away from traditional race machines with the shift to a more comfortable ride and a more comfortable position. The bike is designed for adventure, GT says. It was designed to be able to be raced at a gran fondo, yet ridden off the beaten track on dirt or gravel roads aided by the inclusion of large volume tire and disc brakes.

The kicked-up chainstays and forward-positioned seatstays are designed for comfort: the kicked-up chainstays and forward-positioned seatstays are designed for comfort

The kicked-up chainstays and pencil-thin fibreglass seatstays are designed for comfort

Patrick Kay (PK), product manager for GT Road, said there is a disconnect between most everyday riders and pro bikes, “with prices hitting $10,000 that’s not accressible, and more of a race bike than most of us will ever need.”

“In the US and Canada, gravel and adventure road riding is a movement, not a trend,” PK said. “Gran fondo riding in the US and UK is strong and growing. In Australia we are seeing riders taking advantage of the vast network of outback dirt roads, and even in Italy we are seeing events inspired by the gravel road Strada Bianca.” GT is aiming the Grade at all of these riders.

The GT signature triple-triangle frame is here, but not just for looks, PK said. “By moving the seatstays outboard not only do we reduce the size of the rear triangle but also add plenty of tire clearance,” PK said. “The bonus also off shifting the stays further outboard is the increase in torsional stiffness this enables.”

GT's signature triple triangle: gt's signature triple triangle

GT’s signature triple triangle allow for bigger tyres as well as a small rear triangle

The carbon frame weighs a claimed 965g for a 56cm. The butted alloy frame tips the scales at 1,320-1,350g. The top-of-the-range carbom fork is 475g with the thru-axle dropouts. On the alloy model GT uses a carbon fork with an alloy steerer, which is a little heavier.

The top three frames feature thru-axle dropouts, while the other four models use traditional dropouts and quick-release skewers.

Carbon and glass in the Grade frame

“We wanted to design this bike like you would a high-performance motorcycle,” said Andy Schmitt, the engineer behind the Grade who has designed bikes for Schwinn, Mongoose, GT and Cannondale. “We created a solid foundation with the tapered head tube flowing into a large oversized down tube. This meets the PF30 oversized bottom bracket, which makes for a great terminal for the down tube and the oversized chanistays.”

“The main frame’s more compliant features are a seat tube and seat stays that are designed to flex,” Schmitt said. “By kicking up the chainstays and having the seatstays fitting forward of the axle, that enables movement too. Finally, the top tube is allowed to flex upwards.”

The grade alloy gets the full-carbon fork with 15mm thru-axles and ice-rotor-equipped shimano hydraulic brakes: the grade alloy gets the full-carbon fork with 15mm thru-axles and ice-rotor-equipped shimano hydraulic brakes

Shimano ICE rotors on the higher-end bikes

GT used very stiff high-modulus carbon in areas where ultimate stiffness is needed, but Schimitt wanted a completely different performance for the seatstays. GT experimented with the lowest modulus carbon they had for the long, arched stays, but wanted more flex, so the company ended up testing and experimenting with fibreglass. Fibreglass is has a similar strength to carbon but with a far lower modulus, and it is much cheaper. The fibreglass stays are finished with a final carbon layer to add impact resistance.

GT said the frame has created more than 10mm of deflection when measured at the top of the seatpost when you remove the seatpost flex from the equation.

The seat tube has a bi-directional taper at the bottom bracket; this flattening shape means the tube acts more like a hinge allowing for more fore-aft movement whilst the massive down tube and oversized chainstays and BB ensure drievetrain stiffness. The final component of the “flexi-comfort” design is the top tube; the flat, broad shape restricts the amount of lateral movement, whilst the shallow depth is designed to allow the top tube to arch upwards in the same path as the seatstays.

Details on the GT Grade

GT designed the carbon fork to complement the comfort inherent at the rear. By reducing the length of the taper, making more of the steerer a standard 11/8in diameter makes for more comfort, GT claims, but retaining the oversized lower race means the steering response isn’t compromised. The 15m thru-axle design has a leading axle, so whilst the 15mm combats braking forces and adds steering precision the increased offset to 45mm aids smoothness, GT claims.

The all-carbon fork features a 15mm thru-axle: the all-carbon fork features a 15mm thru-axle

The top-three bikes feature thru-axle forks

The Grade is full of neat touches, like discreet mudguard eyes and a clip-on bridgeless fender mount with o-rings. The PF30 bottom bracket uses the new Praxis Works adaptor, which saves any fuss and faff associated with press-fit. Something that will set bike mechanics’ minds at rest is the full external cable routing. Both drivetrain and hydraulic lines are grouped together with a neat routing system under the down tube.

Stan’s NoTubes new Grail disc road rim, on DTSwiss 240 hubs, tips the scales at a claimed 1,685g a pair. The new Stan’s Grail rim uses a 24mm outside diameter rim, with a large internal diameter of just over 20mm. They are of course tueless compatible, though the Grade ships with a standard clincher set-up. The Stan’s rim is rated far higher (110psi) than the company’s mountain bike rims.

The seven GT Grade models

Grade Ultegra carbon — ?2,999 / US$3,299

  • Drivetrain: Shimano Ultegra 11-speed with BR-R685 hydraulics
  • Gear range: 52/36 and 11-32
  • Rims/hubs: Stan’s NoTubes Grail rims (460g) on DTSwiss 240
  • Tyres: Continental Ultra Race 28c
  • Handlear: GT Drop-Tube bar (14-degree outward flair on the drops) 2014 butted aluminium
  • Seatpost: FSA K-Force light carbon
  • Saddle: FiZik Aliante MG

The new gt grade is an endurance bike designed for everything from sportives to dirt- and gravel-road riding: the new gt grade is an endurance bike designed for everything from sportives to dirt- and gravel-road riding

Grade 105 Carbon — ?2,299 / US$2,599

  • Drivetrain: Shimano 105 with BR-R685
  • Gear range: 52/36 and 11-32
  • Rims/hubs: Stan’s NoTubes Grail rims (460g) on Formula centre-lock hubs
  • Tyres: Continental Ultra Race 28c
  • Handlebar: GT Drop-Tube bar (14-degree outward flair on the drops), 6061 butted aluminium
  • Seatpost: FSA SLK carbon
  • Saddle: Fi’z;ik Aliante MG

The carbon 105 bike looks like a great package: the carbon 105 bike looks like a great package

Grade Alloy X — ?1,599 / US$1,7499

  • Drivetrain: Shimano 105 with BR-R685
  • Gear range: 52/36 and 11-32
  • Rims/hubs: Stan’s NoTubes Grail rims (460g) on Formula centre-lock hubs
  • Tyres: Continental Ultra Race 28c
  • Handlebar: GT Drop-Tube bar (14-degree outward flair on the drops) 6061 butted aluminium
  • Seatpost: FSA SLK carbon
  • Saddle: Fi’z;ik Aliante MG

The alloy x is gt's highest spec alloy grade : the alloy x is gt's highest spec alloy grade

Grade Alloy 105 — ?1,099 / US$1,299

  • Drivetrain: Shimano 105 with TRP HYRD brakes
  • Gear range: 52/36 and 11-32
  • Tyres: Continental Ultra Race 28c
  • Handlebar: GT Drop-Tube bar (14-degree outward flair on the drops) 6061 butted aluminium

Grade Alloy Tiagra — ?899 / US$1099

  • Drivetrain: Tiagra with TRP Spyre brakes
  • Gear range: 50/34 and 12-28
  • Tyres: Continental Ultra Race 28c
  • Handlebar: GT Drop-Tube bar (14-degree outward flair on the drops) 6061 butted aluminium

Next in line is the tiagra model at ?899 / us$1,099: next in line is the tiagra model at ?899 / us$1,099

Grade Alloy Sora — ?799 / US$899

  • Drivetrain: Shimano Sora 9 with Bangle mechanical brakes
  • Gear range: 50/34 and 12-28
  • Tyres: Continental UltraSport 28c
  • Handlebar: GT Drop-Tube bar (14-degree outward flair on the drops) 6061 butted aluminium

The sora-equipped bike will be priced at ?799 / us$899: the sora-equipped bike will be priced at ?799 / us$899

Grade Alloy Claris — ?TBC / US$799

  • Drivetrain: Shimano Claris with Tektro mechanical brakes
  • Tyres: Continental UltraSport 28c
  • Handlebar: GT Drop-Tube bar (14-degree outward flair on the drops) 6061 butted aluminium

The base model $799 claris model shares the same 1,350g alloy frame as the alloy x: the base model $799 claris model shares the same 1,350g alloy frame as the alloy x

Silverback Signo Technica review

Silverback’s Signo Technica is the German brand’s new approach to a trail bike, combining a stiff, agile rear end with a front end that eats up impacts. How’s it done this? By means that’ll surely ignite yet more fireworks in the world of the wheel size debate – it’s mixed 650b with 29in.

Ride and handling: best of both worlds?

On paper, mixing the two wheel sizes kind of makes sense. Up front you’ve got the 29er wheel with its increased grip and ability to roll over lumps and bumps, giving you added control that you want from the front wheel. At the back, the smaller 650b wheel is sturdy, flickable and agile; grip back there doesn’t matter quite so much.

The Signo Technica is far from a bad bike. The 140mm RockShox Revelation fork, which can drop down to 110mm for steeper climbs, when combined with the 29in front wheel gives a ton of control. The 2.25in Maxxis Ardent tyres don’t have the greatest edge on them, but there’s plenty of grip in dryer conditions, and that big wheel does roll over terrain imperfections with ease. At the back, the 650b wheel skips over the ground, verging on being playful, especially if you ride with your weight over the fork. When the Ardent loses traction slips, drifts and skids are controllable, rarely chucking you off the bike.

At times, when front and back strike a harmony, the signo can be a joy to ride…:

At times, when front and back strike a harmony, the Signo can be a joy to ride

Silverback’s marketing bumpf claims that this bigger wheel up front setup helps ‘balance out the trail steepness’, what it calls 279 Dynamic Efficiency Geometry. What really happens is that you get a relatively high front end that works reasonably well on steeper terrain, but can feel slightly pedestrian on flatter sections. The Revelation’s Dual Position Air damper provides a decent level of mid-travel support, which is handy on steeper terrain. With 140mm of travel up front and nothing at the back, when the fork is pushed through its travel, it does steepen the frame’s angles, so that support is certainly appreciated.

We’re not convinced by the actual science behind the 279 Dynamic Efficiency Geometry; there’s certainly no mention of it making climbs steeper…

What the wheels do though is highlight the differences between the sizes. Regardless of which side of the fence you sit on, when the trail gets choppy, the difference in handling becomes apparent. While the front rolls over bumps, no doubt helped by the suspension, the rear feels like it gets caught up on edges, and needs a little extra persuasion to get over them. On technical climbs especially, the Signo Technica feels like a bike of two halves.

The stout construction, with the tapered back end, gives a stiff ride that’s a little unforgiving on the lower back. We tempered this by running the relatively large volume rear tyre at lower pressures.

Frame and equipment: trail fit kit

The geometry is all held together with Silverback’s Vanadium Flow frame, itself a well-put-together and nicely finished piece of kit. The main tubes are triple butted, and smooth welded. Aesthetically it works well – giving a more organic look – but the reasoning behind it, so says Silverback, is that there’s a greater weld area and less stress risers, both of which should make the frame more durable.

The signo technica's smooth welded and triple butted frame is a well made pleasure:

The Signo Technica’s smooth welded and triple butted frame is a well made pleasure

With a trail focus, all the frame features we usually look for are included. A 31.6mm seat tube is ready to take a dropper post (although there’s no provision for stealth routing), there’s a 142×12 Maxle bolt-thru rear axle, press-fit bottom bracket and tapered head tube (which, to be fair, pretty much every bike comes with these days), which keeps the frame tight and stiff. Cables are externally routed, which we prefer because it makes giving them TLC a whole lot easier. They’re also full length, which is ideal for keeping the crud out.

When it comes to the kit that Silverback’s bolted to the frame, it’s clearly done its homework. While some Euro brands are still stuck in the land of long stems and narrow bars, Silverback’s added a 60mm stem and 740mm bars – not quite as short or as long as you could go, but they certainly help you head in the right direction.

The short stem, wide bar combo helps keep steering snappy and responsive, and the bars give better control and keep your weight forward. The bars and stem, along with the post and saddle are own-branded pieces. The saddle and bars have a reasonable shape, although there’s no pressure-relieving channel on the saddle, and there’s a fair bit of backsweep (nine degrees) on the bars. Our only major spec issue is the bolted seat clamp. For a bike designed to hit technical trails hard and then pedal back to the top, it’s inevitable that your multitool will be lost in the bottom of your bag. Just fit a QR please!

Cockpit components are bang on the money, though some may not like the sweepy bars:

Cockpit components are bang on the money, though some may not like the sweepy bars

Shimano kit largely controls stopping and going. The SLX brakes are crowd pleasers, with their dependable power, backed up with Ice Tech pads and 180/160mm Centerlock rotors. The shifters and rear derailleur come from the XT stable, again providing reliable performance, the Shadow+ derailleur featuring the clutch mechanism keeps the bike nice and quiet.

To mix it up Silverback’s gone with a Race Face Evolve crank with 34T Narrow Wide chainring. With Shimano rings not benefitting from the chain retention properties of a narrow/wide design, this allows Silverback to build a Shimano geared bike without needing to add a chainguide. This setup worked well, with the 34/36 bottom gear being just low enough for the majority of our riding.

Shimano supplies the SLX hubs, and Stan’s the Arch EX rims. So long as you take care of the cup and cone bearings, Shimano hubs last well and the lightweight, tubeless capability of the mid-width Stan’s rims have given them an enviable reputation.

Summary: mixed messages

There aren’t many brands around that are mixing up wheel sizes – Liteville being the obvious other one out there. There are times – like on steeper trails and when razzing your local trail centre – when riding the Signo Technica you think it’s a work of genius, with both ends of the bike singing from the same hymn sheet. But at others it feels disjointed, making us wish it had a pair of identical hoops. Oh, and taking two tubes in your pack is a pain in the ass, so we ended up stretching a 650b tube into the front wheel.

This article was originally published in What Mountain Bike magazine, available on Apple Newsstand and Zinio.

Shimano XTR Di2 – Electronic shifting comes to mountain bikes

Shimano has today announced details of a new Di2 electronic version of its top-tier XTR mountain bike groupset.

Rumours, as well as leaked images of the group, have been floating around the net for some time, but now everything is official we can give you the full run-down.

XTR Di2 in a nutshell

XTR M9050 marks the first migration of electronic shifting technology into the world of mountain bikes. The system will use one battery and remain wired, using already proven parts from Shimano’s Ultegra and Dura-Ace road Di2 groups.

So what are the advantages? Shimano claims that XTR Di2 will offer faster and more accurate shifting. Also, with no cables to stretch, it’s said to offer shifting consistency that a mechanical transmission cannot match. Whether that’s true remains to be seen, but one part of XTR Di2 that we really should be taking notice of is Syncro Shift – for those who are running double or triple set-ups it could be a game changer.

Syncro Shift allows the rider to control both front and rear derailleurs with one shifter. Simply shift up or down and the transmission will follow a pre-programmed (and customisable) shifting map, moving both derailleurs when necessary to find the next ratio while maintaining a good chain line. So, that’s less clutter at the bar and more time to worry about things other than gear selection.

XTR Di2 shares its chainset, cassette and chain with Shimano’s recently announced?mechanical XTR M9000 groupset,?so that means Di2 options for single, double and triple transmissions.

Individual components

RD-M9050 rear derailleur

Well done shimano! the m9050 rear derailleur does a great job of hiding away its motor: well done shimano! the m9050 rear derailleur does a great job of hiding away its motor

The new M9050 rear derailleur does a great job of hiding away its motor, which is 50 percent more powerful than the one you’ll find in Shimano’s road Di2 derailleurs. That’s to combat the additional weight that muddy conditions can add to the components.

Just like its mechanical brother, the RD-M9050 has Shimano’s?

Shadow RD+

?clutch retention system. This means a rider can externally adjust the spring tension of the rear derailleur using an Allen key. The beauty of this is that with a motor controlling the shift, the tension at the clutch can be turned up to a level that would normally compromise shift performance for a mechanical mech.

The derailleur will be available in a short- and long-cage option, with the former weighing a claimed 289g.

FD-M9050 front derailleur

The front derailleur doesn't do this quite so well…: the front derailleur doesn't do this quite so well…

The XTR Di2 front derailleur is less subtle than its rear counterpart. It has a claimed weight of 115g and features the same auto trimming technology as the company’s Di2 road components.

SW-M9050 shifters

The shifter isn’t really a shifter – it’s simply a switch that has been given a short yet positive throw to try to replicate the feel of a conventional unit: the shifter isn’t really a shifter – it’s simply a switch that has been given a short yet positive throw to try to replicate the feel of a conventional unit

Thanks to Syncro Shift functionality, XTR Di2 can be set up to run with either one or two shifters at the handlebar, even with a triple chainset. The shifter isn’t really a shifter, it’s simply a switch that’s been given a short yet positive throw to try to replicate the feel of a conventional unit. The claimed weight is 64g per unit.

SC-M9050 system display

The bottom right of the lcd display features an indicator that displays information for fox's icd suspension system : the bottom right of the lcd display features an indicator that displays information for fox's icd suspension system

The brain of this groupset is a small handlebar mounted LCD display. While riding, the display communicates essential information such as battery level, gear position and shift mode (whether or not Synchro Shift is activated). It’s integrated with Fox’s electric iCD suspension adjustment system – where the bottom right of the display includes an element which shows the suspension mode of a compatible fork and shock. It certainly leaves the door open for nerdy types and perhaps other manufacturers to exploit in the future.

The display also functions as a charging point for the system and a connection to Shimano’s E-tube software, where – just like in Shimano’s road applications – riders can customise a wide range of functions.

Battery and wiring

Di2 xtr battery options: di2 xtr battery options

Bottle cage mount will not be the only option (L) – notice the wires emerging from the head tube (R)

The battery unit as well as the wiring for XTR Di2 are identical components to the ones used in Shimano’s electronic road groups. The battery can be mounted on a bottle cage, in a seat tube and can even be contained within the steerer unit of certain forks (although full details on this haven’t yet fully emerged).?


Di2 technology has, just like it did for the first generation in the world of road, debuted at the top-end of Shimano’s mountain biking range. The pricing alone is likely to keep these parts out of the hands of anyone other than Shimano-sponsored athletes and the very wealthy.?

  • RDM9050GS – ?429.99 (Rear mech short cage)
  • RD9050SGS – ?429.99 (Rear mech long cage)
  • FDM9050 – ?269.99 (Front mech)
  • SWM9050R – ?149.99 (right switch/shiter)
  • SWM9050L – ?149.99 (left switch/shifter

Stay tuned to?BikeRadar?for our first ride impressions on XTR Di2 soon.

New UK mountain bike company Bird Cycleworks takes flight

Bird Cycleworks, a brand new British mountain bike brand, has broken cover with the first of its 650b-only frames. ?

The first frame to fly the nest – well, it’s fledgling because it’s on pre-order until June – is the Bird Zero, a 6061 aluminium hardtail with forged chainstays, stealth routing and a 142×12 rear axle. The Zero is available as a frameset only or in one of five high-end builds, says the company.

While the fact that the bikes are designed and built in the UK is interesting (the frames are actually made in Taiwan) in itself, it’s the business model and service that could be most attractive: Bird sells direct to customers, so prices are competitive, and the company offers a lifetime transferrable warranty on its products.

Perched at the top of the range bike is the Zero.AM (?2,000), which is fitted out with a RockShox Pike 150mm/120mm Dual Air fork, Hope Hoops Pro2 Evo, RaceFace Atlas cranks, Hayes Lightweight discs and Shimano XT shifter.

At the bottom of the roost is the Zero.4, a Shimano 2×10 bike kitted with an X-Fusion Velvet fork, a RaceFace Turbine 650b wheelset and Shimano Deore brakes.

Bird Cycleworks is nested near Swinley in Berkshire and was hatched in 2013 by three founding partners: Ben Pinnick, Dan Hodge and Dave Cutts. For a bird’s eye view of the all the bikes, visit Bird Cycleworks.