So i want to build myself a 26" dh rear wheel so I chose the dt swiss fr560 rim and spank hex j type rear hub(12x150mm) but when I went to calculate spoke length it gave me diffrent results.
by Proof-Lecture-2523
So i want to build myself a 26" dh rear wheel so I chose the dt swiss fr560 rim and spank hex j type rear hub(12x150mm) but when I went to calculate spoke length it gave me diffrent results.
by Proof-Lecture-2523
4 Comments
That’s usually the case. Rare that spokes are the same length left and right. 0.3 of a mm isn’t enough variance to worry about.
QBP has a spoke calculator that take 3 different calculators and gives you the results. I’d give that a shot and go with the most popular answer
Some calculators calculate the flange distance from the center, others from the outside and the ERD value may also be used differently in the programs. That will lead to differences.
Apart from the spoke length, you only cross once, is that right?
garbage in, garbage out. You need to understand what the numbers mean instead of just blindly slamming them into text fields. Your screenshots don’t show all of the numbers that you’re punching in so no one’s gonna be able to tell you precisely what you’re doing wrong that’s come up with wildly different results from each of the different calculators, but that last screenshot: Your rim is 30mm wide between the hooks where the tire sits, but that’s not what the wheelbuilding tool is asking you for. It’s asking you for the material thickness at the rim bed. So that’s why that particular result is so, so far off the others.
Regardless, I think **all** of your numbers are completely fucked. From what I *can* see in the screenshots, you’re calculating for a 1-cross build, which is absolutely not how you should be building a DH disc-brake wheel. Looking up the specs of your rim and hub and punching the numbers for a standard 32-spoke/3-cross build into [freespoke](https://kstoerz.com/freespoke/?link=1&e=538&wL=39.5&wR=29.5&dL=58&dR=64&s=2.6&n=32&xL=3&xR=3), I’m coming up with 261mm on the left and 259mm on the right, which sounds much more correct for a 26″ wheel.
But don’t just take my word for it and buy spokes based on that. I STRONGLY recommend that you have the rims in hand and [actually measure the ERD with the nipples you intend to use](https://www.parktool.com/en-us/blog/calvins-corner/measuring-effective-rim-diameter) before buying spokes. The ERD is not a physical measurement on the rim, it’s the diameter to where the tips of the spokes end up – which is floating in space inside the rim cavity. So every manufacturer-reported ERD is making assumptions that may not be true for your wheelbuild, and some just flat out report the ERD incorrectly.