Calibre Bikes, the GO Outdoors house brand, has dominated the sub-£1,000 market for a few years now, and for good reason. Up-to-date geometry and well-considered components packaged up at ridiculously competitive prices have made its bikes seriously tantalising — especially for riders on a budget.
After years scooping all the accolades for its cheaper bikes, Calibre has decided to up the ante and venture into the longer travel enduro/trail market.
Its latest offering, the Sentry, comes in two builds, but shares the same frame. The priciest bike will set you back £2,800 (with the £5 discount card) and is fitted with some seriously flash kit, but it’s the cheaper of the two (seen here) that we think is most exciting.
The Sentry sports a slack 64-degree head angle which is paired with the short (42mm) offset Yari forkSteve Behr/MBUK
People tend to think that cheaper bikes always lean towards the conservative end of the geometry spectrum, but that isn’t the case with the Sentry, which doesn’t just embrace but bear-hugs the current trend for long, low and slack.
The chassis is built around 29in wheels and, according to Mike Sanderson, the man behind the Calibre range, is “built to go fast”. After five prototypes, the final numbers will no doubt raise eyebrows.
A super-slack 63.8-degree head angle, low-slung 335mm bottom bracket and long 1,240mm wheelbase scream high-speed stability. Reach ranges from 445mm (S) to 506mm (XL). The medium tested here sports a reach of 465mm, which felt spot on for my 5ft 8in height. To keep climbing as efficient as possible, Calibre has opted for a steep 76-degree seat angle.
Calibre wants to ensure punters won’t need to upgrade to burlier tyres from the get-go, so specs the Tough casing WTB Vigilante (front) and Trail Boss (rear). The meaty 2.6in Vigilante offers a decent amount of traction when the conditions become more challengingSteve Behr/MBUK
At the rear, the Sentry boasts 150mm / 5.9in of travel, delivered via the linkage-actuated single pivot backend and controlled using a RockShox Deluxe shock, which is mounted to the subtly curved down tube.
All cables are externally routed, which makes maintenance that bit easier, and many will appreciate the use of a threaded bottom bracket. There’s not quite enough room in the front triangle to squeeze a water bottle cage in place though.
Calibre Sentry kit
While the pricier Sentry gets the top-end Lyrik from RockShox, I was still really impressed with the feel of the cheaper Yari, complete with DebonAir springSteve Behr/MBUK
Considering the price, the kit on this, the cheaper of the two models in the range, is fantastic and really well considered. One of the highlights has to be the SRAM Guide RE brakes. It’s rare to see these impressive stoppers on a bike at this price but, considering this bike’s intentions, Calibre has made a wise choice speccing them.
SRAM also takes care of gearing in the shape of its 12-speed NX Eagle transmission — again, not regularly seen on bikes at this price, especially those bought through shops.
Calibre has opted to use a RockShox Yari RC fork with the shorter 42mm offset, which I felt paired nicely with the super-slack head angle. Compared with rear-wheel travel, the fork actually delivers a little more at 160mm / 6.3in.
There’s 150mm of rear wheel travel controlled via a RockShox Deluxe shockSteve Behr/MBUK
Aside from designing a bike that goes fast, Calibre also wanted to ensure it could be wheeled out of the shop and taken straight to a race, without the need to switch a single component. This is why it’s opted to use WTB’s Tough casing High Grip compound tyres. A 2.6in Vigilante sits up front, while a 2.4in Trail Boss takes care of business at the rear.
If I was being picky, I’d argue Calibre could have gone for the Fast Rolling version of the Trail Boss, but I’m pleased to see a brand spec such solid, albeit heavy, tyres that should stay inflated no matter what you throw at them.
I was beyond impressed to see that Calibre has specced SRAM’s powerful Guide RE brakes. Most bikes at this price, regardless of intended use, tend to get cheaper, less potent stoppersSteve Behr/MBUK
Thanks to the 440mm seat tube, the medium works well with the 150mm Kore dropper post, which I had no reliability issues with throughout testing.
If you have an extra £800 in your pocket, I’d certainly recommend checking out the pricier Sentry. This bike gets the all-singing all-dancing RockShox Lyrik RC2 fork, plus a Super Deluxe coil shock complete with remote lockout, which is seriously impressive for the money.
Calibre Sentry first ride impressions
Rob giving the new enduro focused 29er from Calibre a good going over throughout testingSteve Behr/MBUK
Although I was initially worried about the size of my medium test bike (the small offers a more compact wheelbase of 1,218mm and a reach of 445mm), the Sentry felt very comfortable and easy to ride. The back-end required almost no fettling after I’d set the sag, which is a real plus too.
There’s support where it counts and enough progression to handle things when you do start trucking on — something that this bike encourages as soon as it’s pointed downhill.
It’s by no means a featherweight at 16.16kg, though. Combined with the slow-rolling tyres, I thought the Sentry was going to be a battle on the climbs, but thanks in part to that steep seat angle and wide gear range, it’ll winch up most trails with no real drama and less effort than you might expect.
The Sentry uses a single pivot, linkage actuated suspension system with a shock yoke connecting to the base of the rear damperSteve Behr/MBUK
Drop into something with gravity on your side and the Sentry really comes into its own. The stability on tap encourages you to push the bike as hard as your nerves will allow, while the low-slung chassis and well-centred ride position bolsters confidence and control as you drift from turn to turn.
While the back-end isn’t the plushest out there, it deals with the hits in a composed fashion and offers enough support and feedback through the pedals to ensure you know what’s going on beneath the tyres.
As you might imagine, while it’s a bike capable of attacking trails at speed, its weight and size mean it’s not the liveliest or most playful of machines on flatter trails. That long back-end also means it takes more effort and a little more practice when it comes to lofting the front wheel up and over obstacles.
That said, I had no issues flicking and popping from line to line when I wanted to, even if it required a little more muscle.
The Sentry’s intentions are clear from the outset though, and it’s on the technical descents where it really shines.
The burly tyres offer plenty of traction, the Yari fork delivers its travel with enough control and comfort so you’re happy to pick those awkward off-camber lines and stick with them, while the SRAM Guide RE brakes are fantastic at killing speed in a split second.
Calibre Sentry early verdict
Overall, what Calibre has delivered here is pretty incredible when you consider the price. I’d have no qualms sending the Sentry headlong into a steep, root-riddled tech descent without swapping a single component, which says a lot about just how capable and well-considered this bike is.
Calibre Sentry specifications
The new Calibre Sentry is an absolute steal at £2,000 (with the £5 Go Outdoors discount card). Great geometry, well-considered kit and a balanced ride mean it’s certainly not afraid to go fastSteve Behr/MBUK
Frame: Aluminium with 150mm (5.9in) travel
Fork: RockShox Yari RC with 160mm (6.3in) travel
Shock: RockShox Deluxe
Drivetrain: SRAM NX Eagle 12-speed
Wheelset: WTB STi29 rims on Formula hubs
Tyres: WTB Vigilante High Grip Tough 29×2.6in (fr) and WTB Trail Boss High Grip Tough 29×2.4in (r)