Sub 10kg (22lb) has always been a benchmark for the best lightweight mountain bikes. However, with XCO courses becoming more and more technical and riders demanding bigger tires and dropper posts to tackle them, 10kg bikes are rarer than ever. That's not to say it isn't achievable, many bike brands manage to get their hardtails and even their best full-suspension mountain bikes under the 10kg mark.
In reality, you’d be hard-pressed to tell any difference in the ride between a 10.2kg bike and a 9.8kg bike but the psychological/bragging rights of going under 10kg is massive. Developments and demands of riders mean it’s harder than ever for cross-country mountain bikes to hit that target though. 29in wheels, tires, and forks will always be heavier than 27.5in or 26in (remember them?) but their smoother speed makes them an XC essential. Some top racers like Nino Schurter are routinely using 2.4in tires now too, while others are wide rim or wide handlebar fans.
Most of the world’s fastest racers are now using dropper posts for extra control on challenging courses despite a 400-500g penalty over fixed posts. Huge cassettes mean simpler 1x transmissions are often heavier than old double chainring setups too. Even fitting a remote control lockout to the best XC forks adds significant weight, but again most racers won’t be without it for smashing smoother climbs.
Best lightweight mountain bikes under 10kg
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Canyon has grown from a small trailer-based spares ‘shop’ at German XC races to a global bike-brand superpower with an ever-increasing number of World Cup and World Championship race wins under its belt.
This top-line hardtail features a 69-degree headtube angle, 1,154mm wheelbase, and 455mm reach on a size large. It also gets a sweet exclusive paint job, and the full build comes in at 8.9 kg.
For the build kit, the bike features a SRAM XX1 Eagle AXS drivetrain and a remote-controlled RockShox SID SL fork. SRAM also provides the braes with Level Ultimates bringing the stopping power. Reynolds Blacklabel XC wheels are paired with Maxxis tires to keep you rolling.
It has a sharp classic XC ride feel, which Guy found out when he tested the bike, "the unfiltered stiffness, super lightweight, and direct drive efficiency of the Exceed CFR will be an unholy trinity that’ll create a religious experience for many hardcore racers. They’ll rejoice in the rapid, climb-friendly steering feel from the relatively steep head angle and 740mm bars too.
On a budget? There are multiple other Exceed models to choose from with more wallet-friendly build kits. They feature the same frame geometry but will have different components and will be heavier, however even the lower spec Exceed CF is still sub 10kg.
For more, check out our full Canyon Exceed CFR LTD.
Scott totally redesigned their Scale cross-country hardtail which had remained unchanged for the last six years. With the launch of the new bike, the Scale sees a radical redesign that revolutionizes Scott's hardtail race bike.
Built from Scott's HMX SL carbon Scott has not only refined the frame's carbon layup but also the construction and hardware. There are some new features too, including adjustable headset cups as used on the Spark to give + / - 0.6-degree head angle adjustment. The new geometry can be adjusted between 67.9 degrees as supplied, neutral cups (included with the bike) for a 67.2-degree, to a super slack (for XC) 66.7 degrees in a few minutes. The seat angle is 75.3 degrees in the standard 67.9 head angle position and reach is measured at 463.6mm on a medium.
Scott put Guy through his paces at the Scale's launch but the bike's qualities weren't lost on Guy. "Between the hyperventilating, lactic burn, and hallucinogenic lack of oxygen though it was still clear that the new Scale is blisteringly, brutally fast. While it’s not the lightest hardtail option by over a kilo and the DT Swiss-based hub internals have a ten-degree lag before engagement, when they do connect, the power delivery is sledgehammer direct".
Regarding components, Scott has kitted their new top-of-the-range hardtail with an equally best-of-the-best spec list. Highlights include Trickstuff Piccola Carbon brakes, a Quarq power meter, carbon finishing kit from Syncros, and the incredibly light Silverton SL2-30 CL carbon that weigh a claimed 1280g per wheelset and are the same wheels Tom Pidcock choose to ride at the Olympics.
The astronomical asking price of the Scale RC SL is far beyond what most people could possibly comprehend spending on an XC bike. the good news is the Scale RC World Cup retails for less than half and still slips under the 10kg mark.
For more details head over to our full Scott Scale RC SL review.
In terms of frame weight, Orbea’s carbon fiber Alma OMR race hardtail isn’t crazy light at over 1kg, but they’ve done something radical to get complete bike weight low enough to kill on the climbs. Depending on what fork you run, Orbea’s 550g Spirit Rigid fork will save you 800-1,000g over a 100mm suspension unit to bring complete bike weight well under 9kg. The kinked, super-flat top tube is designed to help dissipate the extra shock coming through from the front end too, although the long, tapered, carbon legs deliver a smoother ride than you’d expect. The super-slim stays are designed for extra flex but there’s still plenty of meat around the cranks and chainstays for kicking hard and making that low weight count. The fork is also the same length as a 100mm travel unit so swapping around won’t disturb the agile, short wheelbase handling.
The same OMR frame appears on the top four Alma models with another four Alma models using the slightly heavier OMP frames. Whatever your starting point, Orbea’s ‘MyO’ customization program lets you pick and mix from a range of components to tune cost, weight, and character. You can even choose from multiple color options (fully custom on the top models) so that you get a truly personalized Alma built for you in Orbea’s Basque factory. The direct-sell model means they’re generally very good value too although you will have to wait longer for delivery than if you pick an off-the-shelf bike from your local shop.
Mondraker has redesigned the Podium hardtail for 2021, so it has a more conventional look but keeps its lightweight and 'Forward Geometry.' The brand claims that it has created the world's lightest production frameset.
Born on DH race tracks thanks to the work of Unno’s Cesar Rojo and others, Forward Geometry was the spark point for the current trend for super-short stems on extended reach frames. Mondraker was the first mainstream brand to be bold enough to use the concept right across its range from gravity bikes to cross-country machines. The Podium was designed a while ago now but the geometry has been refreshed, bringing a 463mm reach, 68.5-degree headtube angle, and a 70mm stem on a size large.
If you can afford the price tag for this beast of a hardtail, then you'll be smashing the climbs in no time.
Santa Cruz’s original Highball race hardtail was so stiff it could make your feet numb in under an hour in the wrong shoes and rattle teeth out on rocky descents. That meant we weren’t expecting an easy ride when we met its new race rod.
Santa Cruz has completely flipped priorities with the new Highball though, realizing that fighting fatigue and preserving performance is more important than ultimate power punch. The 67-degree head angle balances snappiness and stability and the 460mm reach (large size) is long for an XC bike, which helps calm control on flat-out fast sections. The frame compliance also noticeably improves the bike’s ability to conform to the trail for traction as well as reducing the chance of you being rattled offline or ricocheting randomly off rocks and drops. The threaded bottom bracket and three bottle cage mounts are designed for the long haul. Despite shaving weight from past frames it has a no weight limit, no questions asked, lifetime frame warranty.
Riders can also opt to equip their Highball with Santa Cruz’s Reserve carbon wheels. They’re covered by a similarly no-nonsense lifetime warranty and again the ride feel is obviously damped and shock smoothing rather than skittish and sketchy. That means you can hit stuff hard without worrying about comfort levels or construction quality and it’ll work great as a daily driver.
Unsurprisingly, power delivery definitely isn’t as taut as some pure racers, but trail connection and rollover performance are excellent.
A couple of years ago now, Trek created an all-new type of full-suspension bike, using what it calls ‘Isostrut,' a tiny but full feature remote control Fox air shock, hidden inside a Kashima gold stanchion that bolts into the cutaway top tube. The flat flex stays stretch forward to a tube that slides along the stanchion, connected to the shock via top and bottom slots that also stop twist. Add a main pivot just above and in front of the chainring and you’ve got 60mm of travel with all the usual shock rate, pressure, and damping adjustments plus a remote control lockout. Fewer pivots and linkages mean reduced mass and maintenance and it also gives a very clean frame look with room for two bottle cages if the race/ride is long or hot.
Trek has certainly committed hard to the concept too, with no carbon-framed, purely hardtail bikes in its XC lineup. ProCaliber 9.7 and below use its road-bike-derived ‘IsoFlex’ scissor frame. Meanwhile, the new Trek Top Fuel beefs up from its previous super-light and twangy incarnation, getting 115mm of travel out back with slacker angles, longer reach and a much stiffer power and precision-friendly ride.
We have personally not tested the Isotrut-equipped Super Caliber yet, the top racers in the world seem to have no problem making it go fast on the trails. This is a very "XC" bike, so the unique design certainly won't be for everyone.
Specialized has killed off their impressively light 8.6kg S-Works Epic AXS HT however for 'just' a few more thousand dollars and an extra 1,000 or so grams you can get Specialized's S-Works Epic. A thoroughbred cross-country race bike that has seen success on the world cup race circuit to the grueling marathon stages of the Absa Cape Epic.
The S-Works Epic has one goal in mind and that is to cover ground as fast as possible. The 9.7g weight combined with Specialized Brain suspension, a system that uses valves to differentiate between pedal forces and bump forces, means this bike is set for every type of climb from long and smooth to steep and technical. Specialized knows that what goes up fast will need to descend equally as quickly and the 67.5-degree head angle means the Epic is not losing any time on the descents.
Although the S-Works Epic is the only model of the range to tip under the 10kg mark, Specialized offers a couple of build options that all benefit from the Epic's Brain platform and are very competitive in regards to weight in their price brackets.
Scott recently updated its long-running Spark XC format; a bold new look and a seriously progressive and tech trail-ready ride mean it has been a real hit. It’s more than accurate enough to get really aggro with too. The latest iteration also has the best Spark suspension by far, with proper chunder-calming, speed-breeding performance in its ‘Open' mode. Push the TwinLoc trigger on the bar though and you can toggle into a tauter, reduced travel ‘Traction’ mode for feisty climbs or fully lock it for sprinting, and that response is matched by the front fork, too.
Arguably the Spark shouldn't be on this list as the range-topping Spark RC SL EVO AXS model doesn't actually meet the sub 10kg criteria for this buyer's guide. We are willing to forgive that 300g though considering it has an uncompromising spec including a Stouter Fox 34, a dropper, and big tires which means you can really rally this bike to its full 120mm of travel potential.
We reviewed the Scott Spark Team Issue AXS model and were very impressed with its performance.
Cannondale is another brand that has always had racing close to its maxed-out heart and the Scalpel HT Hi-MOD 1 is a new super-light hardtail platform loaded with typically left-field features.
Most obvious is the Ocho fork, the latest version of a left-leg-only suspension family that’s now 20 years old. The cantilevered single crown carbon fork makes it the lightest Cannondale fork yet and it’s also competitively smooth once you find the set-up sweet spot. Even after a double decade on the faceted, inset needle-bearing leg technology, the tracking is still a head bender but you’ll soon learn to make the most of it on aggressive overtakes or tire ripping turns. The 50mm fork offset and short stems as standard make for fast yet confident steering despite a slack 66.5-degree head angle although the comparatively short reach (444mm on a large) will feel a little odd compared to the modern crop of longer bikes.
The Ballistec carbon frame shaves weight with a narrow shell 30mm press-fit bottom bracket and Cannondale was one of the first to adopt road bike style ‘Flat Mount’ disc brake fittings. It also uses a Cannondale-specific Ai wheel offset which you need to factor in when upgrading.
What you need to know about the best lightweight mountain bikes
What are the lightest mountain bike frames?
When it comes to frames the big weight penalty that racers are now routinely paying is opting for a full-suspension bike rather than one of the best hardtail mountain bikes. Unless it’s a super-smooth or strength-sapping high-altitude course most of the men’s World Cup XCO field will be on a double-damped rig, and more and more women are lining up on full sus every race. They’re a lot more fun and forgiving outside the tape if you’re not a completely competition-focused rider too. That inevitably means a roughly 250g rear shock plus pivot bearings, other mounting hardware, and extra frame parts piling on the weight. As a result, even the ultra-light 1,870g Scott Spark is still over 1000g heavier than the hardtail Scott Scale and most head-to-head, in-brand comparisons are significantly heavier. Softail bikes like Trek’s Supercaliber race bike or Moot's ultra-premium Mountaineer split the difference in weight and full suspension function.
Are cross-country race bikes lighter?
Cross-country race bikes that are ridden by pros are very light as they feature specs that are either too expensive or not available to the general public. That said it's not uncommon to find brands selling premium models that are even lighter than the bikes their team riders use. That’s generally due to sponsor demands (for example, RockShox SID Ultimate SL forks are heavier than Fox 32 Step-Cast, and Shimano XTR is heavier than SRAM XX1). With no contractual obligations for consumer bikes, sometimes brands just fit cost-no-object component mixes to create a super-light show stopper you can buy off the shelf.
What is the lightest MTB in the world?
Some bikes like Orbea’s Alma M-Ltd and Scott's Scale which can be specced with a rigid fork are lightened further than most of us would regard practical. Alternatively, you can get a bike with an eccentric bottom bracket or sliding drop-outs and go single-speed and ditch gears altogether. If you really want to see what’s possible then click on the infamous gram-hating hangout weightweenies.starbike.com. Or check out how anti-gravity artists like Gustav Gullholm (Dangerholm on Instagram) get Scott Spark and Scale bikes down to 7kg with belt sanders, paint stripper, and ultra-light carbon fiber cockpit and seating combinations.
NB: We’ve had to rely on some manufacturers' weights for this run down, so if you want to be sure of weights take your scales with you when you go shopping. Please contact us if any of the numbers are right off so we can update the feature for everyone else.