Co-op Cycles ADV 2.1 Handlebars: Read Flare, Reach and Stem Bore Separately
Co-op Cycles ADV 2.1 handlebars have several dimensions in the saved item 254161 table, rather than one universal “bar size.” The Aero-Ergo entry lists 31.8 mm diameter, twelve-degree flare, 80 mm reach and 125 mm drop. Its width is described as size-specific, without numerical widths in that row.
Separate the Co-op Cycles ADV 2.1 handlebars' measurements
The Handlebar Shape field identifies a drop bar. Reach and drop then describe different aspects of its published shape; neither is the complete bicycle's frame reach. A short note containing only “80 mm reach” should therefore say that it is quoting the handlebar, rather than the geometry chart.
The twelve-degree flare entry is another separate figure. The saved table does not define a width-measurement convention or provide a width for each frame size. Do not calculate a precise hood width or choose a size-specific bar by assuming a measurement method from a different component.
Read the stem as its own component
The stem is described as Co-op Cycles 6061 aluminum, four-bolt, with an open faceplate. Its entry gives 37 mm stack height, 31.8 mm bar bore and six-degree rise. Extension is size-specific, but actual extension lengths are not supplied in that line.
The matching 31.8 mm wording in the bar and stem entries is useful identification evidence. It is not a complete substitute for identifying a proposed replacement bar or stem. Material, intended use, dimensions and the applicable component instructions remain separate questions; no fitting or tightening procedure is supplied here.
Request the missing size-specific details
When comparing two advertised bicycles, ask which frame size, handlebar and stem are actually fitted. Request the bar width and stem extension for those examples, particularly if a previous owner changed the cockpit. An unnumbered size-specific entry should remain unnumbered until the particular assembly is identified.
The historic yellow ADV bicycle illustrates a drop-bar layout, without establishing these item 254161 dimensions. Broader family context is in the existing Co-op introduction; the brand collection keeps related references together.
FAQ
Does 31.8 mm state the bar width?
No. The record describes width separately as size-specific.
Is the listed 80 mm figure stem extension?
No. It is the Aero-Ergo handlebar's reach entry.
Does the table give every size's extension?
No. It supplies the size-specific description without those lengths.
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/
Copyright notice: No separate photograph copyright notice supplied. Embedded sRGB colour-profile notice: Copyright (c) 1998 Hewlett-Packard Company.
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.