Co-op Cycles Bike Size Chart

1. 01

   Every adult model uses the same 5 height ranges

   Co-op Cycles uses XS through XL on mountain, hybrid, and road models. XS covers 152–160 cm, S covers 160–168 cm, M covers 168–175 cm, L covers 175–183 cm, XL covers 183–191 cm. The ranges meet without a gap, so a rider at 160 cm, 168 cm, 175 cm, or 183 cm sits in two ranges. A rider at 168 cm sits at the top of S and the bottom of M. A rider at 175 cm sits at the top of M and the bottom of L. The range gives a starting size. It does not describe the frame.

2. 02

   The same M has three different reaches

   The label repeats across families. The geometry does not. At M, the DRT 1.2 mountain bike has 450 mm reach and 626 mm stack. The ADV 2.2 road bike has 386 mm reach and 554 mm stack. The CTY 2.1 hybrid has 374.2 mm reach and 607 mm stack. The DRT 1.2 M reaches 75.8 mm farther than the CTY 2.1 M and 64 mm farther than the ADV 2.2 M. Height alone cannot choose between them.

3. 03

   Stack sets the bar height

   Stack moves with the frame, not the label. DRT 1.2 M stack is 626 mm. ADV 2.2 M stack is 554 mm. CTY 2.1 M stack is 607 mm. The trail frame puts the bars 72 mm higher than the road frame and 19 mm higher than the hybrid. If you want an upright ride, the taller stack raises the bars without spacers. Confirm the steerer length before you raise the stem.

4. 04

   Standover differs by family too

   At M, DRT 1.2 standover is 738 mm. ADV 2.2 is 756 mm. CTY 2.1 is 785.5 mm. The hybrid sits 47.5 mm higher over the top tube than the mountain bike. At a 78 cm inseam the DRT 1.2 leaves 42 mm of clearance, the ADV 2.2 leaves 24 mm, and the CTY 2.1 sits 5.5 mm above the inseam. Measure inseam with shoes on, then compare it with the standover on the model page.

5. 05

   Kids sizes use wheel diameter

   Co-op Cycles lists the REV 24 for 127–147 cm. That range is 4 feet 2 inches to 4 feet 10 inches. The label is the wheel diameter, not a frame letter. Read the REV 24 geometry table for standover, stack, and reach. Check the minimum saddle height and the brake lever reach before you buy a bike that lasts two seasons.

6. 06

   Ride both sizes at a boundary

   A rider on a height boundary has two published sizes. Ride both with the saddle at your height. Check the standover at a stop, the bar drop, and the knee position at the bottom of the stroke. The height range narrows the choice. A test ride settles it.

7. 07

   Check the model page, not the family

   REI prints a size chart and a geometry table on every product page. The table lists stack, reach, effective top tube, seat tube, standover, head angle, and chainstay for every size. Read the numbers for the size the height range gave you. Confirm the model year, because REI updates a frame without renaming it. The CTY 2.1 and the CTY 2.2 share the same height ranges and have different geometry.

Need the full sequence, including between-size rules? See how to choose a bike size.