New to MTB, 2020 Trek Top Fuel 9.8 GX power meter?

I just picked up a few weeks ago my first MTB, a 2020 Trek Top Fuel 9.8 GX with a SRAM build, 1x12 with Eagle, dub PF bottom bracket, and what I think is a direct mount 32t chain ring and Truative cranks.

What am I looking at for a power meter? I’ve seen some Quar meters that it looks like I need to change our my cranks and chain ring? Or a Stages one that I need to add a bunch of adapters to?

I’ve got a Stages single sided meters on my Checkpoint and Domane, but have no clue what to go to with a MTB. Something that will let me drop down to a 30t or throw an oval in there if I want to experiment.

Suggestions?

Looks like stages is producing a compatible one?
I’m not 100% sure - maybe call them up and ask?

I’m not 100% sure but I think your options may be limited Power2max if you want to stay with the crankset already on the bike. You’d end up removing your existing chainring & mounting the Power2max unit in it’s place which will leave you with the need to choose a new chainring with 104 BCD. Both Absolute Black & Wolftooth offer oval 30T chainrings that should work with that set up.

Stages makes a single sided meter for SRAM DUB but for some reason, the crank spindle also needs to be replaced. And like you mentioned, Quark is an option if your replace your existing crankset with Quark pm specific XX1 crank arms.

Quarq is only for the XX1 crank, and not sure if P2M makes one. Also unsure if stages makes one for the GX crank since its hollowed out in the back

Assioma with the XPEDO bodies may be your best bet especially if you plan to run oval rings

Just go with a solid and reliable solution…the quarry PM on SRAM eagle cranks. It’s worth the investment in the long run and the data is far more reliable that Stages.

Rotor inpower is an option too.

I’ve had the best success with Quarq on my mountain bikes, but they have been XX1.

One concern with single sided PM’s, like a Stages, is if you like to descend with your left foot forward. I have a Stages on one of my bikes and it is great except that I get big power spikes on the descents because I like to descend left foot forward. Depending on how you track and use your data it may not be a big deal, but I found it annoying all my short Power PR’s were from this. Now that I’m on dual-sided Quarq’s I don’t see it anymore.

It sounds like a Quarq is my best bet. Is there any reason other than cost not to go to their cranks and chain ring? Could I still run something like an absolute black oval if I wanted to give that a shot? I know it can somewhat mess with the power readings.

I am sure Power2max will work, their customer service will let you know. I have one with an absolute black oval chain ring and it hasn’t missed a beat.

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Look at how your current chainring is mounted to the cranks.
image

If you have the one on the left (those 3 bulges are the the bolts) then a Power2Max will fit. I’ve had one for almost a year now and have had zero issues. You will need a new chainring (104BCD I think) but you would be able to use an AB Oval like you mentioned. Also, if you message them with what crank you have then I’m sure they’d be happy to point you to the correct type of mounting.

If you have the one on the right then you would be able to use a quarq. But I don’t think Truvativ makes an 8 bolt crank. So if you went that route you would need a new crankset and chainring.

I don’t think you can go wrong with either one. Quarq has a great reputation but I think that’s mostly because of it being a US based company and has been around a bit longer. But I have also heard nothing but good things about P2M’s.

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I have the Quarq XX1 on my XC bike with AB 34t oval chainring and it’s perfect. I can’t comment on how the oval affects power as I haven’t ridden this bike on a turbo to compare, but I get solid readings like all my other Quarq meters give me.
Super simple swap too, just take old crank off and put new one on, leaving the chainrings attached.

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