For functionality, features and price we think Quarq power meters are hard to beat. These replace your entire crank set and give you reliable and accurate power data with virtually no setup and excessive calibration. It is nearly always best to ask to sellect and fit the right unit for you. However, here is the info on the choices to make.
The GXP version has a 24/22mm spindle and will need a SRAM GXP bottom bracket. This can be either threaded or push fit. Frames with BSA, BB86/92 for example. The BB30 version has a 30mm spindle for frames with BB30 or BB386evo bottom brackets.
After that you need to choose if you want the BCD (bolt circle diameter) or 110 or 130. This will determine what chainrings you can use. This needs to be matched with the choice between hidden bolt and non-hidden bolt. Essentially this is if the 5th chain ring bolt is fixed to the crank itself, or not. The hidden bolt version is where the bolt that fixes to the crank is not visible.
Lastly, you need to choose your crank length. It maybe worth taking this upgrade opportunity to get this correct rather than just getting the same as you currently have fitted.
DZero combines 10 years of technology advances with new features such as dual Bluetooth low energy and ANT+ wireless data transfer and the new Qalvin BLE app.