Sigeyi AXO Shimano MTB Power Meter

This is not a long term review since I’ve only had this a couple weeks and done a few rides with it. Overall very happy so far. I was a little skeptical not having ever heard of this company before, but after reading some credible reviews online I decided to try it out. The setup was very simple once I had the proper security torx bit and spider tool to remove the stock spider and then separate it from the chainring. FWIW, the spider tool can be had for less than $10 and I found the right torx security bit at my local Ace for $4. Accuracy was my big concern but after having done some testing of this vs my Assioma Duo pedals as well as on the Saris H3 trainer, both indicated this power meter was well within 1% of the readings from both of those other sources for any interval over 30 seconds (accuracy measurement on intervals less than 30 seconds always shows more variation across all power meters in my experience) so I haven’t even needed to adjust the power scaling on this, but I’m glad I have that option via the app in case it ever becomes necessary. That’s actually quite impressive accuracy in my experience and I’ve had quite a few power meters over the years, most quite a bit pricier than this. Its worth noting that even though this is dual sided measurement, the power balance metric accuracy has its limits because its trying to measure left side power sensing the strain registered on the spider which is on the right side: some calc adjustments are involved there. I think this makes the overall power measurement even more impressive really, but you can very quickly see where the balance calculations fall apart if you try pedaling with just one leg: the result is not 100%/0%. But as long as you’re pedaling with both legs and don’t have a balance skew worse than maybe 65/35 this thing tends to be right on point so from a practicality standpoint there’s really nothing to criticize here. I also like the design of this power meter for MTB purposes because its almost entirely out of harm’s way. And for the price, is there a better value out there? If you want power on your MTB then I would not hesitate to suggest this option. If I had to pick all over again, I’d go right back and buy this same thing.