CLEARANCE: Schroedinger’s Folding Frames


Now 23% off, while supplies last (5 frames only).

Inspired by famed physicist Erwin Schroedinger, who described a thought experiment about a hypothetical cat that was both alive and dead at the same time, these folding frames are both new and used at the same time—and yet, they’re very real.

During the peak of COVID, when we had no inventory coming in and customers still wanting bikes in sizes we didn’t have, we routinely converted bikes from one size to another, moving all components as needed across frames and adding our own forks. This now leaves us with five folding bike frames that have never left a bike shop, yet have already been on (and off) a bike.

How can you recognize a Schroedinger’s Frame? Look very closely at the seat tube, and you’ll see a compression mark in the paint where a front derailleur used to be. If you’re adding another front derailleur (specifically a triple), you’ll cover it up and never notice. But if you’re building a 1 X setup, that mark will be the first blemish on the bike that you later take out in the rocks, mud, dirt, sand, etc.

In some cases, the headset or bottom bracket may already be installed. Or, if you just want us to do it, there you go. Done.

But because of that small blemish, we are discounting these frames $200 off the standard CHANGE 833 frames that have all the same accessories. 

These are mostly in pine green.

SKU: CF833-SF Category:

Additional information

Weight14 lbs
Dimensions41 × 7 × 23.5 in

17", 19", 21"


Black, Pine Green

MTB Frame Sizing

Start with your body height and inseam (if you're on the border line or have short legs). Then find the matching frame size.

sizing icon
Height (Inches)5'1" to 5'8"5'8" to 6'2"6'2" to 6'7"
Inseam (Inches)29"31"33"
Frame Size (Inches)17"19"21"
Head Tube (Inches)4.3"4.7"5.9"
Top Tube (Inches)23"23.6"24.6"



If you’re building a bike to go off the beaten path, you’ll want to start with something light, yet rugged. Unlike other folding bike frames, this light (5.5 lb) double-butted aluminum hardtail frame has passed the ISO 4210 destruction test suite for mountain bikes. And yet, unlike other MTBs, a bike built on the CHANGE 833 frame can travel everywhere in your car trunk, free from weather, road grit, and curious hands. After your day on the mountain, you can enjoy your dinner and trail stories in peace, knowing that your amazing ride is safely tucked away from view in your trunk.

SPECIFICATIONS833 folding mountain bike frame
Frame Sizes17" (430mm),19" (480mm),21" (530mm)
Folded Size26" x 26" x 10" frame only (See CHANGE 811 and CHANGE 812 for full-bike folding)
Frame ColorsMatte Black, Pine Green
Frame ConstructionHydroformed, double-butted, aerospace-grade 7005 Aluminum
Ruggedness certificationISO 4210 destruction test suite (passed)
Brake mount typePost-mount disc brakes
Axle typeQuick release
Cable routingInternal with removable ports
LatchesTop latch CNC meshed-tooth with butterfly-style cam (like a ski boot latch). Bottom latch cam compression lever (like a seat post latch)
Other featuresSeatstay hook for front wheel storage when folded, rubberized seat tube foot to protect bike when folded.
ForkNot included. Pairs well with a tapered headtube, MTB-style fork, either solid or shock.
Frame Weight2.5kg (5 lbs 8 oz)
PedalsWellgo flat pop-off pedals (2nd generation)
INCLUDEDPress-fit FIRST headset, seat clamp, black canvas carry bag, derailleur hanger, manual, warranty card
Seat Post Size31.6mm
Bottom bracket73mm English threaded
Wheel sizes700c, 27.5", 26"
Max tire width2.4"