Co-op Cycles ADV 2.1 Size Chart: Compare Reach and Stack in the Saved Record

2026-11-06

The Co-op Cycles ADV 2.1 size chart is useful when its five columns remain attached to their row headings. The saved item 254161 table lists XS through XL, with separate reach, stack and standover measurements. A frame label alone does not preserve that information or settle a rider's fit.

Yellow Co-op drop-bar bicycle with rigid fork and disc brakes beside parked cars — Historical yellow Co-op ADV-family bicycle, photographed beside parked cars. Exact model and manufacturing year are unverified; this is not a photograph of the ADV 2.1 item 254161 configuration. Matthew Bellemare, New Bike Day; CC BY-SA 2.0. Original source-hosted JPEG unchanged. Photograph source (https://www.flickr.com/photos/bellemarematt/54472185594/); Matthew Bellemare (https://www.flickr.com/people/bellemarematt/); CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0/).

Compare the Co-op Cycles ADV 2.1 size chart columns

Reach is 365, 375, 385, 393.4 and 403.4 across XS, S, M, L and XL. Stack follows a different sequence: 542, 560, 581, 602 and 623. REI states millimetres unless otherwise indicated. Preserve the decimals instead of rounding neighbouring frames into an apparently identical cockpit.

The XS-to-S reach change is 10 mm, while the M-to-L change is 8.4 mm. Stack rises by 18 mm between XS and S, then 21 mm between S and M. These simple differences describe the printed chart. They are not a prediction of how far a person's hands will move on an assembled bicycle.

Standover answers a separate question

The standover row reads 689.5, 728.2, 758.1, 788.1 and 814.3 mm. Its sizing notes define the measurement from the ground to the top of the top tube at its midpoint. That is a bicycle dimension, whereas the chart's height bands are rider recommendations. Neither is a prescribed clearance above a particular rider's body.

REI defines reach horizontally from the crank centre to the head-tube centre at head-tube level, and stack vertically to the top of the head tube. Those definitions explain why an effective-top-tube figure cannot simply replace either row in a comparison sheet.

Bring a labelled comparison to the fitting

Record the candidate size and the relevant dimensions beside those of a correctly identified existing bicycle. Mention changed bars, stems or other equipment rather than treating the frame chart as the complete riding position. The historical yellow ADV image cannot supply a size measurement. Use the Co-op model topic and brand background to keep other family names separate.

FAQ

Are the values stated in millimetres?

Yes, unless the chart explicitly indicates another unit.

Does reach increase by the same amount each time?

No. The printed increments differ between some neighbouring columns.

Can the photograph establish a rider's size?

No. It supplies neither a measured frame nor a fitting assessment.

Sources

Manufacturer record saved 4 November 2026; reread 6 November: ADV 2.1 item 254161 (https://www.rei.com/product/254161/co-op-cycles-adv-21-bike).

Photograph credits and permissions

Photograph 1

Original title: New Bike Day

Creator: Matthew Bellemare (bellemarematt); creator profile: https://www.flickr.com/people/bellemarematt/

Original source URI: https://www.flickr.com/photos/bellemarematt/54472185594/

License / permission: CC BY-SA 2.0

License / permission URI: https://creativecommons.org/licenses/by-sa/2.0/

Modification notice: Original source-hosted JPEG retained byte for byte for this article. Source-described earlier photographic process: Nikon N80 | Nikon AF Nikkor 28mm f/2.8D | Kodak Vision3 500T @ 800 Digitized with Sony a7R III & FE 90mm f/2.8 Macro G OSS | CineStill CS-LITE | Valoi 360 135 Holder Home developed in Fujifilm Negacolor | 4:18/35C | Paterson Tank, AGO Film Processor Negative Lab Pro v3.0.2 | Color Model: Basic | Pre-Sat: 3 | Tone Profile: Linear Deep | WB: Auto-Neutral | LUT: None Embedded XMP additionally records conversion from Sony ARW to TIFF and TIFF to JPEG, with Adobe Photoshop Lightroom Classic 14.2 (Windows) saves on 22 April 2025 at 12:07:50 and 17:11:39 -04:00. It records exposure +0.14, whites +11, incremental temperature +2 and tint -6; distortion, lateral chromatic-aberration and vignette correction already applied. Crop angle is 0 and HasCrop is false. These are source metadata statements, not alterations made here.

Source disclaimer: No endorsement by the photographer, REI or Co-op Cycles is implied. No warranties are given; other rights may apply. The depicted bicycle is dated photographic family context, not proof of the current ADV 2.1 specification, manufacturing year, maximum load or fit. Share adaptations of the photograph under the applicable ShareAlike terms.