Built for boundless gravel adventures, the Purple Pie is your all-terrain accomplice.
Whether you’re heading into the hills or cruising endless backroads, the Purple Pie is designed to go wherever your curiosity leads. With clearance for chunky 55 mm tires, it’s ready to tackle rough terrain, loose gravel, and everything in between. Its geometry strikes a sweet spot between responsive handling and relaxed comfort, making it ideal for long days in the saddle.
All of this, built by hand in Saxony!
A bike, that’s ready to write it’s own story.
While its sibling has already explored continents, the Purple Pie is just setting out. We can’t wait to see where riders will take it — across borders, through forests, over mountain passes. It’s quick when needed, steady when it counts, and always dependable. Like a loyal companion, it’s there for every twist and turn.
Get bridged, not breakfasted
While tire and rim combinations can vary, the custom Pinio bridge design generally provides enough room to run full-on mountain bike tires. That means more grip, more comfort, and more freedom to choose your terrain.
We designed the Purple Pie’s bridge in-house to hit our performance goals and make welding smoother for our frame builders. It’s what gives the bike room to run up to 55 mm tires — and yes, that means real mountain bike rubber. Tire and rim combos vary, but the bridge makes space where it counts.
So no eggs here — just a solid steel bridge that keeps your ride crisp, clean, and ready for anything.
Geometry
Specification
All Sour Bicycles frames are made by hand, one-by-one, in our own facility in Saxony, just outside of Dresden. We use custom tubing designed and drawn for our frames, it’s a multi-butted heat-treated CrMo steel that’s ready to stand the test of time. All our steel is produced from a partially recycled product and drawn by one of the worlds leading production facilities in Taiwan, the beating heart of the worlds bicycle production.
Our dropouts are designed in-house in Dresden and cast made for us.
The seat clamp is designed in-house as well and is integrated into the frame. Should it ever fail, the frame can be professionally modified to use a traditional clamp, if repair of the original clamp is not possible. We have never seen one fail.
By The Numbers
Headtube: 44 mm upper and lower
Pinion Smart.Shift Gearbox Frame Bridge
Axle: 12mm x 142mm thru axle
Seat post: 27.2mm
Brake standard: FM160 Direct
Wheel size: 700C/29“
Tire clearance: up to 55mm
Tubing: Custom drawn, multiple butted, partly heat treated SOUR CrMo (we love steel)
Bonus facts and features:
Fender and rack mounts
Recommended tire size 45mm – 55mm
Two water bottle mounts inside frame, a third bottle mount under downtube
internal brake hose routing
Business Fork
The Business Fork is our carbon gravel and adventure fork designed for all the adventures, big and small!
We designed this fork in-house and worked with our long-term production partner in Taiwan to make it. We have tested this fork at EFBE in Germany and pass their Tri-Test with flying colors!
Specs
Maximum Tire Width: 55mm
Axle to Crown Length: 403mm
45mm Rake
Tapered Steerer Tube 1½” – 1⅛”
Thru-axle 12mm x 100mm
3 Cargo Cage Eyelets on Fork Legs
Internal Dynamo Cable Routing
Flat-mount Brake Mount 160mm
Fender Mounting Possible
Weight With Full Steerer and Axle: ±565g
Brake Mount Thickness: 35mm
Below are the frame weights for each size of the Sour Purple Haze. These weights do not include powdercoating, but please keep in mind that your chosen powdercoat may be heavier than the average coating we use. Fades, gradients, and metallic colours can weigh more than single solid colour powdercoat. If you are interested the final weight, please get in touch. Weights are averaged over three frames per size. We apply a wax coating on the inside of the frame for rust prevention, this will also add a small amount of weight.
Purple Pie Frame Medium = 2795g ±50g
Small Parts: Bolts, rear axle, brake mount, derailleur hanger= 160g
Included with your frame
Included with your Purple Pie frame or frameset is all the grommets and small parts to run any cabling you wish (as longh ist it’s internal lol) You get a rear thru-axle of course, and if you’re ordering a frameset, you get a front axle with your fork as well. Headsets are only included if you add one to your order.
