The signature flattened top tube gives vertical compliance but lateral stiffness - it really is an all mountain bike. That long wheelbase combined with the slack front end, size specific chainstays and a lowered BB give stability and control through the rowdiest of terrain.
Transmitter is designed around Boost 148/110 standards and 650b 2.6/.8 tyres, and optimised for 1x groupsets. The geometry and extra grip from those big tyres means even the most sheepish rider will tackle those steep sections, up and down, like a pro.
Transmitter frames now feature internal cable routing through the downtube, integrated headsets, through-axle hubs, refined dropouts, butted tubes and smooth welds (and 3 shiny new colours).
Transmitter is a bike that just fits in with hard riding. This new version is still the fun trail bike it’s always been, and will still be a perfect partner for multi-day epics or short and fast trail centre blasts, but the changes we’ve made have raised the Transmitter’s limits, so you’ll be able to push the bike harder than ever before!
At a Glance
- Quick, agile, and stable for trail centres and big mountains.
- Frame: Sonder Transmitter; hand welded 6061-T6 triple butted; vertically compliant laterally stiff tubing.
- Drivetrain: SRAM GX Eagle / 1 x 12 / 10-50
- Brakes: SRAM Guide R
- Forks: RockShox Pike Ultimate RCT3 / 27.5 / 150mm
- Seatpost: X-Fusion Manic Drop Seatpost and Lever / 31.8mm / 125mm
- Wheelset: Love Mud Rumpus 650b+ Boost MTB Wheelset / XD
- Tyres: WTB Vigilante TCS 2.8" (front) and Trail Boss TCS 26" (rear).
Hand welded 6061-T6 triple butted frameset
Not all tubes are equal, Transmitter uses tube walls of different thicknesses to get material where it is needed and save weight where it isn’t.

Dropper seatpost ready
The Transmitter frame is compatible with a dropper seatpost so even the most sheepish riders can tackle those steep sections head on like a pro.

Vertical compliance and lateral stiffness
The strikingly flattened top tube is the spoonful of black magic we need to make the frameset both rigid and forgiving in all the right places. Stable yet nimble, the geometry has been tweaked to give a spirited ride.

Internal cable routing
Clean lines and tidy cables thanks to fully guided internal routing.

Wheel compatibility
Designed around Boost 148/110 standards and 650b 2.6/.8 tyres

Chain guide ready
Transmitter can be fitted with a chain guide. (ISCG 05 compatible).

Build | Transmitter GX Eagle |
---|---|
Frameset | |
Frame: | Sonder Transmitter Frame |
Fork: | RockShox Pike Ultimate RCT3 / 27.5 / 150mm |
Headset: | FSA Orbit C-40-ACB Headset / 7.8mm Spacer |
Seat Clamp: | Love Mud Gromit / 34.9mm |
Group Set | |
Brake Front: | SRAM Guide R / 950mm |
Brake Rear: | SRAM Guide R / 1800mm |
Rotor Front: | Avid Centreline Rotor / 180mm |
Rotor Rear: | Avid Centreline Rotor / 160mm |
Rear Mech: | SRAM GX Eagle Rear Derailleur / 12 / Long |
Rear Shifter: | SRAM GX Eagle Trigger Shifter |
Chainset: | SRAM GX Eagle Crankset DUB / 170mm / 32 |
Bottom Bracket: | SRAM Bottom Bracket / DUB |
Chain: | SRAM GX Eagle Chain / 120 Links |
Cassette: | SRAM XG1275 Eagle Cassette / 12 / 10-50 |
Finishing Kit | |
Stem: | Love Mud Piskie Stem / 31.8mm / 35mm |
Seatpost: | X-Fusion Manic Drop Seatpost and Lever / 31.8mm / 125mm |
Saddle: | Love Mud Abode / Black |
Tape/Grips: | WTB Wafel / Black |
Handlebar: | Love Mud Aspect Riser |
Wheelset | |
Wheels: | Love Mud Rumpus 650b+ Boost MTB Wheelset / XD |
Front Tyre: | WTB Vigilante / Light High Grip / 27.5 / 2.8 |
Rear Tyre: | WTB Trail Boss / Tough Fast Rolling / 27.5 / 2.6 |
Tubes: | WTB Inner Tube / 27.5 / 2.5 |
Weight | |
Frame: | S: 2.0kg; M: 2.03kg; L: 2.07kg; XL: 2.1kg |
Built: | S: TBC; M: 13.06kg; L:13.06 kg; XL: TBC |
Pedals not included with full builds |
Sizing
It is important to get the right size bike, if the bike fits it will be faster, more comfortable, and easier to handle. You can also take into consideration the standover height to ensure you pick a bike that will be a good fit. If you measure your inside leg and ensure there is a minimum of an inch from the toptube to your crotch this will give you enough seatpost adjustment to find your optimum saddle height. Generally we recommend:- Small
- 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 of 6ft 2in +

Transmitter
Size | Small | Medium | Large | X-Large |
---|---|---|---|---|
ST - Seat tube | 410 | 440 | 470 | 485 |
TT - Top tube | 581 | 603 | 623 | 647 |
HT - Head tube | 105 | 115 | 115 | 130 |
HA - Head angle | 65 | 65 | 65 | 65 |
SA - Seat angle | 75 | 75 | 75 | 75 |
CS - Chainstay | 425 | 425 | 427.5 | 430 |
BB - BB drop | 52 | 52 | 52 | 52 |
FO - Fork offset | 46 | 46 | 46 | 46 |
WB - Wheelbase | 1144 | 1169 | 1191 | 1220 |
SO - Stand over | 750 | 768 | 783 | 796 |
RE - Reach | 422 | 442.5 | 462.5 | 482.5 |
SK - Stack | 589 | 598 | 598 | 612 |
Weight: S: 2.0kg; M: 2.03kg; L: 2.07kg; XL: 2.1kg |
Alloy trail frame with integrated tapered headset for a clean, low front end |
Hand welded 6061-T6 triple butted frameset |
High-quality extended welds |
Optimised for 150 mm (540 mm axle to crown) suspension forks |
Internally routed cables |
Boost 148 rear spacing to allow huge tyre clearance while benefitting from a stronger wheel |
Threaded 73 mm BSA BB shell for no-creak assembly |
Chainstay mounted disc brake for clean lines and damage protection |
Reverb Stealth port |
EN 14766 compliant |
The Transmitter frame is suited to a low profile 2.8” tyre or aggressive 2.6” tyres, some larger 2.8”s may rub the chainstays in use |
Author:A great blend of swaggering, speed-breeding stability sharpened up by instantly reactive, traction-chasing, short stem steering .... Alpkit resets expectations with its new hardtail.
Guy Kesteven

Author:"With slackest head angle, longest reach and shortest stem, the Sonder Transmitter is built for bombing, inspiring confidence to fully attack descents."
Alan Muldoon

Author: Rachael GurneyThe Transmitter is a playful, all-mountain rig with some hooligan tendencies. It suits all manners of riding from trail centres to more natural riding to exploring wild bridleways. If you want a ‘one-hardtail-does-it-all’ then the Transmitter will do that in spades.

Author:If you’re a numbers nerd or geometry geek you’ll recognise that while these are significant changes, they aren’t all that extreme and should result in a well rounded riding machine rather than something that only rides in one direction.
Andi Sykes

Author: MBR Read More: hereA bike that descends with complete confidence

Author: What Mountain BikeGenuine game changer .... crazily capable, radical geometry, hardcore hardtail that maximises the control and speed ... outrageously good value ... reset our definition of cost-effective bike performance .... very very nearly saw Sonder take the overall win.
