So I had some broken spokes and thought I’d replace them. There must be standard sizing right?.. Wrong. It seems to be ridiculously complicated to determine what kind of replacement spoke you need. Even armed with the make and model of my hub and rim (the two things that determine what kind of spoke you’ll need) I couldn’t find any resource that told me what replacement spokes I’d need.
Anyway, I wrote these notes so I don’t have to do all the research again when I forget it!
How to determine which replacement spokes you need
First off, try and contact the manufacturer of your bike and ask them.
If that fails, measure an existing spoke. This should be ok if you have fairly standard spokes. Measure its width at each end and in the middle, because some types of spoke vary their width e.g. are thinner nearer the middle. Measure its nipple width (the bit it screws in to). Measure its length, from the point where it hooks on to the hub to the wheel rim.
You can actually calculate spoke length from hub and rim measurements, but that gets really complex. I’ve linked to a couple of spoke calculators at the end of this page that should help with this.
Thickness aka gauge
Spoke thickness is often measured in gauge rather than mm. Here’s the conversion table from Wikipedia’s article on the Spoke wrench - Sizes:
| Spoke wire gauge | spoke size | nipple size | usage | Park tools |
|---|---|---|---|---|
| 15 | 1.8 mm | 3.23 mm (0.127 in) | DT Swiss, Sapim and Wheelsmith nipples | SW-0 |
| 14 | 2.0 mm | 3.30 mm (0.130 in) | most European | SW-1 |
| 13 | 2.3 mm | 3.45 mm (0.136 in) | most Asian | SW-2 |
| 14 | 2.0 mm | 3.96 mm (0.156 in) | Shimano C50/C24/RS10/RS30 | SW-3 |
I measured the width of my spokes and their nipples and they match up with the 14g measurements, which makes sense as I’m in the UK.
- Wheelbuilding - Spokes from Sheldon Brown. There is loads of info here, though it can get rather complex if you start exploring his site.
Length
TODO: Coming soon (just as soon as I’ve replaced my broken spoke)
Spoke calculators
You’ll find loads of spoke length calculators on the internet (see bicycle spoke length calculator). Here are two that I particularly liked:
- With any luck this will have your hub and rim in its database, or at least one of them to save you measurements: Edd, a spoke length calculator
- This one has nice diagrams of what you’ll need to measure (once you’ve selected an option): Spoke calculator
