I'm starting this thread to help track PowerTap versions. CycleOps has a history of undocumented and opaque revisions, especially with their pre-built wheels at Performance Bike. I bought a wheel and Little Yellow Computer in 2005, and I only knew that it would be a PowerTap Pro because other forum users had posted about it.

I got the PowerTap Pro wheelset at Performance at the end of May, manufacture date April 2013. The description online lists a 2032 battery. The User Guide (21476, 10/12) is a combination of the 07/11 User Guides available at https://www.cycleops.com/pdfManuals/: G3/G3C (20373D) for most and Pro (20374D) for table of measurements. The end cap is the PowerCap with removable electronics and 2032 battery. The Pro 70.0mm flange diameter appears correct on rough measurement. There is a blank ring around the PowerCap: it appears to be retrofitted into a Pro hub shell.

The confusing thing is that the Pro had already been redesigned for late 2011–early 2012, coincident with the G3 introduction, with a lighter shell and 2011 SL+ internals (2 x 357 batteries in a holder). All the photos I have found at online stores show the old end cap if visible (the Performance photos are from the freehub side). I find it somewhat implausible that all these stores are still holding inventory of the old version.

The PowerTap rebranding last month will probably add yet another revision, although the omission of the Pro might indicate its discontinuation.

Good luck, man, but I think Cycleops has screwed your pooch on this one. They've created such a cluster of confusion, I don't know how you can sift through it at this point. Even their stationary bikes exhibit the company's tendency to induce unnecessary confusion, e.g. model names like 300 Pro vs Pro 300PT (I probably messed that up, but that's my point, sh_t is confusing!)

PowerTap dropped the prices on the G3 down to roughly where the Pro was. This probably moves the G3 into PowerTap's entry-level spot and confirms that the Pro is being discontinued. VeloNews article; Thread

I know it's bad form to resurrect an old thread but I figured future searchers might benefit, so why not.

As of this date (7/4/2017) Saris, a.k.a. Cycle Ops, a.k.a. PowerTap, has PowerAgent 7.9.14 available from their Web site. I got a "pre-owned" CycleOps wheel with a g3 hub, and set about trying to update the firmware, since the wheel had been sitting around for a few years. Long story short, PowerAgent 7.9.14 is basically worthless on both Mac OS X 10.12.5 (Sierra) and on Windows 10.

So I searched a bit, and located this directory on the Saris Web site, which contains PowerAgent 7.9.20, dated 6/27/2017, in both Mac and Windows versions. A lot of other stuff is there, as well.

I'm still unable to update the firmware on my hub, but it pairs with my Edge 510, so whatever. But maybe I'll call them to see if I can learn anything.

Saris eventually emailed back, providing a direct link to download the 7.9.20 version of PowerAgent, and I tried again. First I woke up the hub by pedaling/applying torque to the hub, and then I attached the cap (battery still in) to my Windows 10 machine, and clicked "update firmware." The software found the hub, ID'ed the firmware, and suggested an update with instructions on how to proceed (disconnect, remove battery, wait 10 seconds, reconnect, and update).

It worked and the hub paired with my Edge 510. Let's hope it stays paired.