How do you measure bead seat diameter?

bead-seat diameter, depending on how high the rim flanges stick up above the bottom of the rim channel. Lay your measuring tape or ruler across the rim from one side to the other. Get the largest measurement, between two points directly opposite one another.

What is the bead seat diameter?

Bead Seat Circumference (BSC), or Bead Seat Diameter (BSD), where the tire bead seats in the rim, is the most accurate measure. French Metric tires are measured by diameter in millimeters, and by width in letters (A is narrow 20mm, D is wide 50mm). An exception came with narrow 700-size clincher tires designated as C.

Is the rim diameter measured at the bead seat radius?

Just like wheel diameter, rim width is measured from bead seat to bead seat, rather than from the rim flange. The width of the wheel in this example is 7 inches. The most common wheel widths vary from 6″-14″.

What is the bead seat of a rim?

The bead sits at the inner lip of the tire that meets the wheel, opposite of the tire’s tread. Imagine a tire without a wheel. The bead is easy to spot on a dismounted tire as it sits at the base of the sidewall and has a slightly wider profile. Also, just like sidewalls, your tire has two beads to meet the wheel.

How is rim ERD calculated?

Measure the length of a nipple (dimension B in the figure) and add it twice (once for each nipple). The result is Effective Rim Diameter (ERD). Thus, ERD = A + 2B.

What is the difference between 700c and 622?

29″ / 700c (ISO 622 mm) Here we have two more common wheel sizes that are in fact, exactly the same! The standard modern road bike wheel has an ISO diameter of 622 mm and is referred to as 700c (makes sense, right? /s).

What is nominal rim diameter?

NOMINAL RIM DIAMETER = Diameter of rim seat supporting the tire bead. Examples: 13″, 15″ and 16.5″. OVERALL DIAMETER = The diameter of the inflated tire without any load.

What is the purpose of the bead seats?

Proponents say the seat covers allow air circulation, and they massage and relax the muscles. Auto store manager A. J. Taylor recommends the more expensive brand with more durable wooden beads strung together with cloth instead of nylon cord.

What is the diameter of a 700c rim?

The more useful number is the diameter of the wheel between the bead seats for the tyre. That’s controlled by ISO standard 5775 and is 622mm for 700c wheels.