I’m looking into a Quarq for my bike that’s equipped with a SRAM Force 1x GXP (110 BCD) crankset. Seeing as Quarq has moved to DUB, their older GXP option is likely going to be used.
Is there anything inherently wrong with buying a used PM that “works great” ? Is it a total crapshoot?
Just like buying any piece of used equipment, there is a risk. But your worst case scenario is that you send it to Quarq for recalibration. You’ll likely still be well ahead of the game.
I’ve bought two used stages, and both have been fine. Obviously they had no warranty left, so there is always a risk.
Quarq has a good track record for reliability so you should be fine. I bought my old stages Gen2 used and ran it for 3+ years then sold it to a guy who’s still using it. My buddy on the other hand bought what ended up being a water damaged Gen 1 Stages which gave him readings of 1600w in the parking lot
If it’s broken, you’ll know, but seeing as it’s a quarq I think you’ll be good to go
What is wrong with that? He should be happy, barely anybody can push such watts! 
Would be one hell of a zwift racer
Right. Normally I would buy new, but it’s not an option. I’ll be happy as long as it reads higher than my KICKR Snap!
Thanks for the feedback
I bought my Inpower chainset nearly new, but for half price. That to me made sense. Still a substantial outlay at GBP 350. Having used the chainset, I would be happy to buy new, seeing the impact it has on my training. Its a bit like buying your first ever decent bike. Maybe start out by trying a second hand one first.
It’s like anything, buying used can be as good or better than new, or it could be worst. I’d have no problem with a used power meter, provided I knew its history.
I’ll have a S Works Dual Sided (165mm) power meter for sale soon. Doesn’t fit what I wanted it for, but bought it from a friend who used it on his TT bike. Knowing it’s history, I had no problem buying it from him in the first place (he’s getting out of racing due to injuries).
Buy on ebay where there is a money back guarantee. Test the power meter, and return it if it is “not as described”.
Generally avoid the first generation of any of the power meters as it seems like none of the manufactures figured them out but after that is less of a risk. (Early quarks didn’t have temp compensation and water incursion issues)
This is exactly what I was thinking.
I’ve bought 3 used powermeters over the years, no issues with any of them. One was off weightweenies and others off ebay. I look for crank arms in nice condition, rings looking ok, and ask why they’re getting by rid of it
My first power meter was a used Quarq Cinqo Saturn. It was old and abused when I bought it. Then I abused it for a couple of years. When i finally got a Kickr core to get something to compare it’s power numbers to, the numbers were within a couple of percent.
So my single experience with used pm was good.
Over some years between my wife and I we’ve had 3 used power tap wheels and 2 used Quarq DZeros.
All were great initially, only one of the PowerTap wheels needed to be sent back for rebuild / calibration (and only after some years or using it)
I continue to look for applicable used crank power meters today as one of our newer bikes is incompatible with our spare powertap (needs disc) and would like to avoid swapping cranks.
I’d probably agree with using mild caution and aiming for meters with good reputations (2nd or later generations as others noted)
I purchase used items all the time. For the most part great deals can be found. Last year I purchased a Specialized (4iiii) Dura Ace Dual sided PM from a very popular and active seller on Facebook marketplace and the right side would not calibrate. I contacted the seller and got the “It worked when I shipped it”. I tried everything to fix it and in the end I over paid for a single sided PM. That purchase stings a little. I sold my old PM on Ebay and whoever purchased it got a perfectly working PM at a good price. I still buy used when I can but when it comes to electronics you do need to use some caution and go with your gut feeling and research the seller the best you can and buy from someone with a outstanding reputation.
Good info here. It’s very common to see the phrase “It works perfectly”, great, it turns on and works perfectly, but is it accurate and consistent?
I guess that’s my only concern with going used is not knowing whether or not it’s measuring power the way it did when it was new.
Thanks for the help, all.
My Rotor InPower Road reads between 8% and 10% more W when compared to my Kickr or my MTB bike (another Rotor), therefore being useless…
I’m sure it’s the one off because I mounted both bikes on the Kicker, recording the same session in separate separate data sets.
I bought it second hand, but I can’t blame the fault on that.