Sonder's boutique titanium all-round trail bike gets a nip and tuck for its latest version, and there's plenty to be pleased about.

Product Overview

Sonder Signal Ti GX Eagle


  • Sublime ride quality and frame finish combined with good sizing and fit, RockShox Pike Ultimate fork balances the ride characteristics of the frame, Plenty of stem height adjustment


  • Slow, heavy Good Year tyres, BB height it overly tall, Geometry is confusing as Sonder does not make it clear that it’s listed with 20% sag


Sonder Signal Ti GX Eagle with Pike Upgrade first ride review

Price as reviewed:


British brand Sonder creates a well-curated line of bikes, spanning road, gravel and mountain bike. The Sonder Signal Ti GX Eagle is an updated version of its popular hardtail, built from titanium, and assembled in the UK.

Need to know:

  • Updated 3Al/2.5V titanium 29er hardtail with a boutique finish at a competitive price
  • Optimised for a 130mm travel fork to complement the trail hardtail geometry.
  • Semi-size-specific chainstay lengths offer a semi-balanced weight distribution.
  • Equipped with Sonder’s Alpha 29 tubeless-ready wheelset – assembled here in the UK.
  • Four frame sizes, S-XL, all rolling on 29in wheels, there’s also a frame only option for £1,399.
  • Order online or try one for size at Alpkit’s stores.

British brands have a long history of turning out well executed hardtails, especially those of a more hard-hitting nature. And while aluminium and steel tubing seem to rule this genre, titanium is making a resurgence; with smaller, direct-to-consumer brands pushing hardtail design forward and not shying away from price tags that are well into full suspension territory.

Titanium has been a core part of Sonder’s range since the brand’s birth in 2016, and with design and product manager Neil Sutton’s background having a strong gravity focus, bikes such as this Signal Ti are high on the agenda. I’ve spent the last ten months on a steel Signal ST as my longterm test bike, so I was keen to see if stepping up to the titanium frame made a noticeable difference to the ride quality and, more importantly, if it really is worth the extra outlay.

But first a bit of background. Initially the Signal was only available in titanium and as the recipe proved successful, a steel frame Signal ST was then introduced resulting in the range of bikes and frame options you see today. The latest iteration of the Signal Ti frame is not an all-new design, even though Sonder says that option was on the table. Instead, it’s had a nip here and a tuck there, so it’s more V1.5 rather than V2.

So what are the basic Signal Ti ingredients? Sonder has stuck with 29in wheels front and rear, with no intention of moving to a mullet/MX design – as seen on Starling’s stainless steel Roost. Sonder’s take is that the relatively short chainstays and taller BB height give the required dose of agility, while the bigger wheels keep all round versatility. The frame is optimised for a 130mm travel fork, which I feel is the sweet spot for a hardtail; it’s all too easy to slap on a big fork to give a bike more hardcore credentials, but in doing so it often makes compromises elsewhere.

Take a closer look at the Signal’s vital statistics and it’s clear that Sonder has chosen to retain an all-round trail bike feel. So rather than shifting it into enduro hardtail territory the bike has a 63.5º head angle and 74º effective seat angle. And while the head angle sounds pretty progressive, we need to keep in mind these are un-sagged static figures, where the head angle and seat angle will both steepen up with a rider onboard.

The same is true of the reach measurement. My XL test bike only measures 473mm, but the reach increases to 492mm as the fork sags. In short, the Sonder Ti is longer and steeper than the static numbers imply. It’s also worth noting that Sonder does not list the geometry static, instead it lists it with fork sag at 20%.

Sticking with the geometry, the Signal Ti has a tall 328mm static BB height and retains the semi-frame-size specific chainstays. I say “semi” as Sonder uses two lengths, it used to be three, across the four frame sizes. My XL test bike measured up at 435mm – in keeping with well-regarded 29in hardtails such as Stif’s Squatch but 15mm shorter than Whyte’s 629 V4.

Take a step back from all the numbers and it’s clear that the Sonder Ti is one amazing looking bike; understated for sure with its sandblasted graphics, but just look at those welds, so clean and well-finished. Internal cable routing on the front end simply adds to the smooth, sleek lines.

Sonder has added some stunning detailing too – especially the chainstay bridge and dropouts – and along with the bridge-less seatstays the Signal Ti has a more contemporary and premium feel when compared to the steel version. Yes, the absence of ISCG tabs on the BB, no under-top-tube tool mounts and the distinct lack of chainstay protection raise an eyebrow, but the switch to a SRAM Universal Derailleur Hanger is a sound move.

How it rides

Expectations were high with this hardtail as the steel Signal ST I’ve been riding has proven a very capable yet easy to get on with bike. And sure enough, the fit of the Signal Ti was very familiar, with the 35mm length stem and 780mm bar feeling spot on. Sonder leaves plenty of uncut length on the fork steerer too, where the large stack of spacers encourage you to fine-tune the bar height or slam it down low if necessary. There’s the option to change stem lengths when ordering the bike too.

Hitting the trails, I expected that smooth ride quality of the steel frame to be nudged up a notch or two on the Signal Ti, after all that’s a key part of a titanium frame’s appeal. And the Signal Ti didn’t disappoint… dishing out a super-supple ride that’s almost comparable to riding 27.5in Plus sized tyres at low pressures. So yes, it is a noticeable step up from the steel frame Signal ST.

And while there’s heaps of comfort, control isn’t compromised; the frame offering a directness, that although not in the same league as an aluminium frame, is noticeable and appreciated. Hit a battered and beaten section of trail and the bike tracks as well as any hardtail can, and you get the feeling that the frame’s compliance is adding a touch more grip, which in turn helps you hold that sketchy line.

The 130mm RockShox Pike Ultimate fork is a great match too. There’s enough small bump sensitivity to complement the Signal’s refined ride quality, but with ample support from the Charger 3 damper it helps reduce big swings in the dynamic geometry.

So the Signal Ti is a plush ride, but does it offer a weight advantage too? Sonder lists the titanium frame at an impressive 2.06kg for the size XL, that’s almost 1kg lighter than the steel Signal ST. With a full SRAM GX Eagle transmission, Code R brakes, RockShox Pike Ultimate fork and Sonder’s own Alpha 29 wheelset, the XL test bike’s spec certainly reflects the £3,339 price tag, but it hit the scales at 13.47kg, which sounded a touch portly for a high-end Ti hardtail.

It didn’t take long to identify that the additional weight was hidden in the rubber… those chunky Good Year Newtons might well be the Trail spec models, but they added over 300g to each of the wheels when compared to the tyres on my Signal ST longtermer – which runs identical wheels, cassette and rotor spec. Switching the stock tyres to a lighter duty spec in a 2.35in width added a noticeable amount of zip to the bike without any obvious downsides for the bike’s trail riding intentions.

So tyre spec aside, has Sonder nailed the new Signal Ti? It has certainly delivered a 29er titanium hardtail with a ride quality and finish that easily justifies the price tag. Sonder has also nailed the damping characteristics of the frame and the quality of the finish too. It just needs a lower BB height and faster-rolling tyres to bring the best out in it.


Frame:3Al/2.5V titanium
Fork:RockShox Pike Ultimate, 130mm travel
Wheels :Sonder Alpha 29 wheelset, Goodyear Newton MTF/MTR Trail 29x2.5/2.4in tyres
Drivetrain :SRAM GX Eagle DUB 32t, 170mm chainset, SRAM GX Eagle r-derailleur and shifter, SRAM XG-1275 10-52t cassette
Brakes :SRAM Code R, 180/160mm rotors
Components :Sonder Aspect Riser 780mm (31.8mm) bar, Sonder Piskie 35mm stem, X-Fusion Manic 150mm dropper post, Sonder Abode 138mm saddle
Sizes :S, M, L, XL
Weight :13.47kg (29.7lb)
Size ridden :XL
Rider height :6ft 2in (188cm)
Head angle :63.5º
Seat angle :69.4º
Effective SA :74.0º (@770mm)
BB height :328mm
Chain stay :435mm
Front centre :805mm
Wheelbase :1,240mm
Down tube :737mm
Seat Tube :485mm
Top tube :679mm
Reach :473mm