## How is ERD rim 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.

## How do you measure rim diameter?

The definition of wheel diameter is the distance, in inches, measured across the face of the wheel, from bead seat to bead seat. As depicted in the diagram, you will notice the measurement stops at the bead seat and is not measured the full face of the wheel.

## How do you measure a bike tire rim?

Ensure the bike is propped up against the wall or on its kickstand. Measure in millimeters from the center of the wheel to only the inner edge of the tire. Once again, double the figure to determine the diameter. Most adult bicycle tires measured with the ISO system range from 650 to 700 millimeters in diameter.

## How are spokes measured?

Spoke length is measured from the inside of the elbow, as shown in the image below, to the threaded end. When measuring a spoke using a tape measure, a second spoke may be used to hold the elbow of the spoke and the tape measure’s tab, as shown.

## What does ERD stand for rims?

A big part of determining the correct spoke length is using the correct “Effective Rim Diameter” (ERD), a concept that is reviewed in this article. Spoke length that is either too long or too short will be problematic. Too long, and the spokes protrude past the end of the nipple.

## What is RIM offset?

The offset of a wheel is the distance from the hub mounting surface to the center line of the wheel. The wheel offset is measured in millimeters and results in a positive, negative, or zero offset. … Negative offset is when the hub mounting surface is toward the back or brake side of the wheels centerline.

## What do wheel size numbers mean?

The wheel size is the size designation of a wheel given by its diameter, width, and offset. … For example, 17 x 8.5 x +35 designates a diameter of 17 inches, width of 8.5 inches, and +35 mm positive offset (432 × 216 x +35 in fully metric numbers).

## What rim width do I need?

Equivalency table

Rim width | Minimum tire width | Ideal tire width |
---|---|---|

5,0 Inches | 155 mm | 165 or 175 mm |

5,5 Inches | 165 mm | 175 or 185 mm |

6,0 Inches | 175 mm | 185 or 195 mm |

6,5 Inches | 185 mm | 195 or 205 mm |

## How do you calculate tire diameter?

We know the diameter of the wheel is 15 inches, so the diameter of the tire is given by: tire diameter = wheel diameter + (2 * sidewall height)

## How do I know what size my bike hub is?

If you are unsure of your frame spacing or have an older bicycle, measure the hub width to ensure a proper fit. To do this, remove the rear wheel and use a pair of calipers or a ruler to measure the distance between the inner surfaces of the dropouts.

## What size bike wheel should I get for my height?

Road bikes

Inseam | Height | Road bike wheel size |
---|---|---|

Less than 27″ | 5′ to 5’4″ | Bikes with 26″, 29″, and 700cc wheels may fit this rider. |

27″ to 29″ | 5′ 3″ to 5′ 7″ | Bikes with 26″, 29″, and 700cc wheels may fit this rider. |

29″ to 31″ | 5′ 6″ to 5′ 11″ | Bikes with 26″, 29″, and 700cc wheels may fit this rider. |

31″ to 33″ |

## How do I know my bike tube size?

The first number is the diameter of your wheel. Sizes such as 26, 24, 20, 27.5, 29 and 700c are common tire diameters. The second number (after the X) is the width of your tire.

## What size spoke nipples do I need?

Length: Spoke nipples are usually 12, 14 or 16mm in length. If using aluminum nipples, the spokes should be long enough to engage the full length of spoke nipple threads so that the load is carried from spoke to the top of the nipple.

## What is the degree measure of each arc along the rim?

ANSWER: Each arc along the rim measures 60°.

## What is a double butted spoke?

Butted spokes have at least two distinct diameters: single-butted (SB) spokes are larger at the elbow and smaller along the rest of their length, while double-butted (DB) spokes are larger at the elbow and the thread and smaller in the middle section.