Marin Four Corners frame bag: choose the right template before commissioning

Marin Four Corners frame bag planning has a useful primary reference: the manufacturer's FAQ links separate drawings for Four Corners 1 and Four Corners 2. The files are more precise than a photograph of a loaded bicycle. Their model-year and frame-size labels still need to match the actual frame before a bag maker can use them responsibly.

Match the Marin Four Corners frame bag document first

Although the FAQ describes these resources as 2024 onwards, the actual drawings inspected here identify model years twenty-four to twenty-five. Both files contain five size pages, from XS through XL. Save the model name, year label and selected frame-size page together. Do not silently extend a drawing to a later CUES build because its family name is familiar.

Choose the Four Corners 1 file for an identified matching Four Corners 1 frame, and the separate Four Corners 2 file for its matching frame. The drawings can look similar while differing in details. For example, the XS seat-tube dimension shown inside the triangle is 151.6 millimetres in the first file and 150 millimetres in the second.

Use the dimensions without inventing a print scale

The XS drawings show a frame outline, mounting locations and millimetre dimensions, including segments along the top and down tubes. These are reference measurements for a conversation with the bag maker. No one-to-one print instruction was found in the inspected files, so a page printed at an arbitrary printer setting should not be treated as a full-size physical template.

Send the original official file and identify the exact page instead of forwarding a cropped screenshot without labels. Ask the maker which dimensions they use and which measurements they need from the actual bicycle. Retaining the complete drawing helps prevent a useful mounting-location reference from becoming an unsupported claim that every edge of a proposed bag will clear.

Separate mounting positions from a finished bag design

Before commissioning, show the maker the actual frame, the proposed attachment method and anything else occupying the triangle. Explain whether bottle access or another accessory must remain available. The official drawing does not supply a finished bag's usable volume, a weight rating, or approval of a particular manufacturer's straps and bolts.

The historical Four Corners photograph used here provides family context only. It cannot establish the dimensions of a specific frame or prove that a bag fits around an installed component. If the frame falls outside the document's stated years, request a matching drawing or arrange direct measurement rather than adapting a near-looking shape by eye.

Frame-bag drawing FAQ

Does the FAQ label override the years printed in the PDF?

No. Preserve the narrower twenty-four-to-twenty-five scope visible in the actual drawings inspected here.

Can the PDF be assumed to print at full size?

No. The inspected files do not establish a one-to-one print scale; use the stated dimensions with the bag maker.

Do the boss locations establish a bag's load rating?

No. They describe mounting geometry, rather than a finished accessory's capacity or approved carrying load.

Commission from a matched document and actual measurements, keeping the drawing's limits visible throughout the order. For the complete bicycle comparison, see frame and cockpit comparison in the Marin collection.

• Primary reference: Marin FAQ and original bag-drawing links.
• Primary reference: Four Corners 1 bag drawing; model years 24–25, correct frame-size page.
• Primary reference: Four Corners 2 bag drawing; model years 24–25, correct frame-size page.