Frontier is our multi-activity hardtail mountain bike. Ride hard at the trail centre, load it up for a midweek bikepacking trip, pocket your passport and continue around the world. With full rack mounts at the back, Frontier is an adaptable off-road explorer.
The geometry is for long day comfort but it’s no slouch...Read more
At a glance
- 6061 aluminium frame
- Set up as an XC for speed or relaxed for comfort and performance
- Rockshox Recon RL Silver / 100mm / 29 suspension forks
- SRAM SX Eagle Groupset / 1 x 12 / 11-50
- SRAM Level Hydraulic disc brakes
- Bolt through boost 148mm rear spacing
- Rear mudguard and pannier rack mounts
- Sonder Nova 29 Wheelset / Shimano
- 27.5+ and 29" wheel size compatible frame
The 6061 aluminium frame provides a durable and stiff chassis giving a responsive kick as you demand power when the slope steepens or enjoy feedback and precision through the corners.
Available as a fully rigid or with 100mm suspension fork. Set it up for XC race speed or for all day big mile comfort.
Tyre clearance gives you the choice of 27.5+ or 29in wheelsets. Bolt through 148mm boost rear spacing provides the benefit of stronger, stiffer and more efficient wheels.
Why SX Eagle?
SRAM Eagle drivetrains are designed, engineered and manufactured to work as complete drivetrain systems. Its 1x drivetrain is built to be lightweight, strong and intuitive, with the gear range to ride on any terrain.
SX Eagle provides the same Eagle performance benefits as NX Eagle, but at a lower price point. The main differences stem from the choice of materials and finish options, but functionally SX is fully compatible with SRAMs Eagle groupset.Read less
The 6061 aluminium tubing is durable, light, low maintenance and stiff.
Internal Cable Routing
Clean lines and tidy cables thanks to internal downtube routing. Frontier also incorporates routing for a dropper seat post.
Wide Tyre Clearance
Extra width between the chainstays gives you the choice of running 27.5+ tyres up to 3 inches or 29 inch tyres up to 2.5 inches.
Boost Axle Width
The Frontier frame is designed around bolt through Boost 148mm rear spacing providing the benefit of stronger, stiffer and more efficient wheels. Seatstay mounted disc brake for clean lines and damage protection.
Triple Bottle Cage Mounts
Fit 2 bottles in their standard location or run your downtube bottle cage a little lower to clear a bikepacking frame bag. Plus there’s an extra bottle cage mount under the downtube.
|Build||Frontier SX Eagle Recon|
|Frame:||Sonder Frontier Frame|
|Fork:||Rockshox Recon RL Silver / 100mm / 29|
|Headset:||FSA Orbit C-40-ACB Headset / 7.8mm Spacer|
|Seat Clamp:||Love Mud Silent Partner / 34.9mm|
|Brake Front:||SRAM Level / Direct / 850mm|
|Brake Rear:||SRAM Level / Direct / 1800mm|
|Rotor Front:||Avid Centreline Rotor / 180mm|
|Rotor Rear:||Avid Centreline Rotor / 160mm|
|Rear Mech:||SRAM SX Eagle Rear Derailleur / 12 / Long|
|Rear Shifter:||SRAM SX Eagle Trigger Shifter|
|Chainset:||SRAM SX Eagle Crankset / Powerspline / 170mm / 32|
|Bottom Bracket:||SRAM Powerspline Bottom Bracket / 73mm / 118mm|
|Chain:||SRAM NX Eagle Chain / 118 Links|
|Cassette:||SRAM PG1210 Cassette / 12 / 11-50|
|Stem:||Love Mud Piskie Stem / 31.8mm / 55mm|
|Seatpost:||Sonder Seatpost / 31.6mm / 400mm|
|Saddle:||Love Mud Abode / Black|
|Tape/Grips:||Sonder Clutch / Black|
|Handlebar:||Love Mud Aspect Riser|
|Wheels:||Sonder Nova 29 Wheelset / Shimano|
|Front Tyre:||WTB Ranger / Comp / 29 / 2.4|
|Rear Tyre:||WTB Ranger / Comp / 29 / 2.4|
|Tubes:||WTB Inner Tube / 29 / 2.5|
|Frame:||S: 1.84kg; M: 1.9kg; L: 1.98kg; XL: 2.03kg|
|Built:||S: TBC; M: TBC; L: TBC; XL: TBC|
|Pedals not included with full builds|
SizingIt is important to get the right size bike, if the bike fits you well it will be faster, more comfortable and easier to handle. Generally we recommend:
- Riders between 5ft 2in and 5ft 7in Medium
- Riders between 5ft 6in and 5ft 10in Large
- Riders between 5ft 9in and 6ft 2in X-Large
- Riders 6ft 2in and over
|ST - Seat tube||380||430||480||520|
|TT - Top tube||566||602||622||647|
|HT - Head tube||110||130||130||150|
|HA - Head angle||68||68||68||68|
|SA - Seat angle||73||73||73||73|
|CS - Chainstay||445||445||445||445|
|BB - BB drop||50||50||50||50|
|FO - Fork offset||51||51||51||51|
|WB - Wheelbase||1089||1127||1147||1174.5|
|SO - Stand over||764||793||825||853|
|RE - Reach||390||420||440||460|
|SK - Stack||566||580||594||613|
|Frame Weight: S: 1.84kg; M: 1.9kg; L: 1.98kg; XL: 2.03kg|
|Rigid Fork Weight - uncut: 1kg|
|6061 Aluminium frame|
|Optimised for rigid or 100mm suspension forks|
|Internal cable routing through downtube|
|Bolt Through Boost 148mm rear spacing for wheel strength and optimal chainline|
|Fork built around Bolt Through Boost 110mm spacing|
|Threaded 73mm BSA BB shell for no-creak assembly|
|Chainstay mounted disc brake for clean lines and damage protection|
|Triple bottle cage mount on downtube|
|Use a seat clamp with integrated mounts for pannier rack compatibility|
|Clearance for 3 inch 27.5+ or 2.5 inch 29er tyres|
|Reverb Stealth port|
|EN 14766 compliant|
It is a bike that will likely tick many boxes for anyone planning multi-day rides, without first returning home for their tea.
Author: Andy McCandlish
This cracking value and rock solid machine from Sonder is just crying out to be loaded up and taken to the horizon.
Giving several centimeters of squish, their suspension-like characteristics help the Frontier float over rough terrain. With big handlebars, an upright position, and loads of stand-over, the Frontier is great for roistering about on, and could certainly serve as a regular mountain bike.
Author: Katherine Moore
Arguably one of the best value bikes in this selection, Sonder’s Frontier Rigid is a 27.5” (or 29” compatible) mountain bike, armed with a wide-ranging SRAM SX Eagle 12-speed chainset. You’ll find plenty of mounting points for bottles, cages, racks and guards, including mounts on the rigid forks.
The Frontier might be considered a Jack of all trades but the clever bit is, it's able to master most of them.