This is possible because straight-pull spokes can be tightened to higher tensions than J-bend spokes. their dimensions. Screw down the nut until it rests against the ruler. The axle gets in the way when measuring the diameter of the circle of spoke holes (d in the image at the right). Damon Rinard has another description of hub measurements on this site. As long as your tools are good, selecting the wrong spokes for a wheel is more likely to result from an outright mistake than from a measurement error. So if you are going to use a manufactures ERD subtract 4mm. Free Shipping Offer Brass spoke nipples are much stronger than aluminum ones and are more likely to survive this abuse. Here is a quick Video to show you how we measure the rims ERD. This site is protected by reCAPTCHA and the Google. (Yes, I know that the number of decimal places exceeds the precision of measurement, but digital calculators give you the extra digits at no extra cost.).
Multiplying by 25.4 gives 530.2 mm.
Measure to the nearest 1mm or 1/32 inch, or better. Mr Cycling World, your favourite online bike shop is a good place to start! Terms and Conditions A 36-spoke cross 4 pattern pattern is a good choice when the hub's dimensions aren't known or with flanges of different sizes. You could cut a C-shaped recess in a piece of cardboard, mark the spoke-hole spacing as shown in the photo at the left, and then measure it with a ruler. 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. This is a difference in radius and applies to each spoke. See the Spoke Length Calculation Help page for specifics. FAQ: Why do you choose lock nut to flange when many manufacturers show hub center to flange? Do you want to log in, or create an account? High-end wheels with straight-pull spokes often use just 28 or 24 spokes to save weight.
Front Wheel Front Wheel with disc Rear Wheel Rear Wheel with disc.
The second step gives the spoke length, by accounting for the spacing of the hub flange away from the centerline. The main one is, you can now add images to new and current hubs and rims within the database.
Be advised, you may find hubs which use straight pull spokes.
The importance of the hub spoke hole circle diameter depends on the spoking pattern. Next, find the corresponding size tube on our website. Calculating now, the overlocknut distance is 135mm, as in the manufacturer's specification in the drawing above. In fact, there are quite a few older models with missing information. If the spokes extend into the screwdriver slots when the wheel is under light tension, you can't use a screwdriver for initial light tensioning of the wheel.
Measuring spoke length for straight pull hub. Hub diameter non-gear side: mm. DT Swiss Straight Pull Aerolite Spokes - 292mm DT Swiss Pro-lock brass 12mm nipples I came across a post a while back (forget what forum) that had spoke length factors to be applied based on regular Hope hub spoke length calcs. DT Aerolite Straight Pull spoke in an Easton Haven rim. The dimension in red is the OLD (overlocknut distance), and the dimensions in blue and green are the flange spacings. There is no calc for straight pull hubs. The table below summarizes the effects of measurement errors. Why are they different than manufactures specifications?
With both wheels spoked this way, a bicycle tourist would need to carry only one length of spare spokes, despite different flange sizes on the front and rear hub, etc. I am building a race tubular, disc brake, 28-spoke, 3 cross wheel using an XTR 9020 straight pull, 142 mm, 12-mm thru-axle hub and a Major Tom rim.
The Sutherland system includes a tool to find the effective rim diameter for spoking. Insert the bolt. By using a tape with a special scale, this system calculates the diameter for you -- saving time, and time is money if you build a lot of wheels. _________________ You can save any wheel build you create on Spoke Length Calculator which includes custom measurements or any make and model selected from the database. Our Custom wheel program takes into account your bicycle type, body weight and intended use. Also, some hubs and rims have unevenly-spaced spoke holes, but we're not going to discuss them here. A is indicated by the purple line in the illustration at the left, and B by the orange line. Information will open in a new tab. Subtract the thickness of the ruler (here, about 0.5 mm). Multiplying by 25.4 converts to 1629 mm; then dividing by pi, the diameter at the well is 518.5mm. So, we got 508.2 mm by measuring the diameter and 508.5 mm by measuring the circumference. You then need to measure the circumference (distance around the rim). The rim shown is a double-wall rim with recessed spoke holes and no eyelets.