If you plan on having more than one set of wheels (like a set of training wheels and a set of race wheels, or a set of 700c and a set of 650b) then I would recommend a crank based over hub based. If you really only plan on one set of wheels, hub based should be just fine. Not sure what you weigh, but 28spokes seems very adequate to me (165 lbs).

Some frames (like the Exploro) don’t have room for a non drive side power meter like stages, pioneer, etc.

Personally, I love my quarq. Sram support has been extremely good to me and they just seem to work. It’s spider based, so you don’t have to worry about clearance on the chain stays of any bike. You can run 1x or 2x rings just fine. Other than quarq, P2M would be my next pick. Then a powertap hub would be next.

I echo the sentiment that a Gravel bike is often begging for multiple sets of wheels and therefore a hub based power meter is less than ideal.

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I have both 650b and 700 wheels and swap often so I went with a P2M. I have used my Assioma pedals a few times but didn’t want to risk smacking one of them on some of the rockier routes.

I opted for a Power2Max crank based power meter on my gravel bike. I regularly switch between 700c and 650b wheelsets so it was simpler to buy a single P2M spider than building up 2 sets of wheels with a powertap hubs.

I switch wheels way too often... cranks.

I use a stages gen3... good enough for me.

I initially had a Stages and found it to be horribly inaccurate. I recently did the Assioma “hack” using some Xpedo MTB pedals and have been very happy with it. I highly recommend it.

If you are looking to go 2x and want lower gearing and more accuracy than Stages, Power2Max will be releasing their gravel 2x setup in 46/30 and 48/31 for a few different cranks in less than a month. (My teammate works for P2Max)

beating a dead horse

I'm crank based with 3 wheel sets.

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I just went through this process with the additional constraints that I am 2x, I was trying to be budget conscious and I didn’t have a crankset that would work with a Stages or 4iii (an Oval Concept which doesn’t have a flat backside). I was interested in the PT hub but they seem to be in limited supply since the buyout and lacing it into a new wheel wasn’t going to be free.

I ended up scoring a new PowerTap C1 chainring in 50x36 that works great. Total cost was about $380.

Have you considered pedals? I've got quite a few Powertap hubs, and I love them, but if you want to use multiple sets of wheels on the same bike, they get expensive...although they're great if you want to use wheels on multiple bikes.

That said, I've got 3 "gravel" bikes (a beater, a nice one, and a CX bike that's more or less the same idea). The problem is, they all use incompatible wheels...one is rim brake, one is disc brake with a through axle, one is disc brake with a QR.

Pedals allow you to use any wheels, any bike, and aren't prohibitively expensive. If I had it to do all over again, that's the route I'd choose.

Not to highjack this tread, but does anyone know of a spider based power meter that would work with the new GRX 2x crankset? This crank has a little wider Q-factor of 151mm. I have it on my OPEN U.P. which doesn't have room for a crank arm option such as Stages. I'm using the XTR pedals with the shorter spindle so the Q-factor ends up being the same as my Speedmax.

I use the Assioma pedals for my Speedmax but I really don't like that option on the gravel bike as SPD pedals are much easier to use in mud and technical stuff.

There's a very simple "hack" for the Assioma pedals to make them gravel or light mountain bike friendly. I did it a couple of weeks ago and it works great. The Assioma's use the same spindle as the Xpedo MTB pedals. I used some Xpedo CXR pedals.

https://gplama.com/...d-hack-gravel-power/

I want something to let me know when the group is going too hot, provide feedback when climbing, and some metrics when I throw on my street wheels/tires...a Stages PM gets the job done fine considering you can typically find one for a few hundred bucks. I leave it on for CX and display NP only (though, I don't often look) and find it generally lines up with perceived effort - that is, tells me I have more or it's time to back off.

Cool, although you can already get a P2Max derived 48/32 or 46/30 from FSA (as long as you're OK with 30mm spindle)

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There aren't any "spider based" power meters that work with current Shimano road or gravel cranks because those are spiderless cranks.

If you're asking about a replacement crankset that works with the GRX front derailleurs, Rotor Aldhu & Vegast crank arms can be paired with a wider "road disc" axle which results in a 152mm Q-factor & a 46mm chainline. That's close enough to GRX's specs to work (within 1mm). Rotor has their own spider-based power meter you can use, or you can use a Power2Max NG or NG Eco. As of right now, there aren't any subcompact chainring options that can be used with either of those PM's, although somebody above suggests p2Max has something coming soon.

The other option is to go with whatever conventional road crankset you like, with conventional road chainline and q-factor, and swap out the front derailleur for a road front derailleur.....although you might lose some rear tire clearance with this option.

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Thanks you. That's exactly the information that I was looking for. I may wait and see if p2max does come out with a subcompact chainring option.

I have an Open UP in L with a Stages left crank arm (170mm - Ultegra). It's close, but I have never had any issues due to clearance. The shop I bought the frame/power meter at has installed Stages on quite a few Open's without issue.

I just bought a powertap hub, mainly for CX/Gravel bike, but also for MTB. I have a hardtail and FS MTB and 2 cx bikes. Hardtail is 135mm, FS is 142 mm TA. CX bikes are 142 mm. Powertap hub is ideal for swapping between them. Will do so seasonally and for some specific events. More interested in training with power than whether I use power while racing.

I don't trust crankarm-based power for off-road. Lots of false signals that are difficult to filter out.

Looking at rims I want something solid that can take reasonably high pressures for a range of 32 mm (50-60 psi) to 2.2 inches (25-30 psi). Normally use ZTR Crest but they won't go to higher pressures. ZTR Grails are great but a bit narrow for MTB. At the moment I'm choosing between Easton ARC 24 (24 mm internal) and DTSwiss X412 (22.5 mm internal). Both are in the 450 gm range.

Best source for straight pull spokes I can find is Thor USA - very good prices. I think Provelo is the B2B version that LBS can order from.

I've had several road powertap hubs and they've been super reliable. Only knock I have on the disc powertap is the proprietary rotor. Apart from that, I can't see why people are so unenthusiastic. Off-road is really hard on components and powertap is very robust and flexible for swapping between bikes.

You can get Easton EC90 cranks with an integrated cinch PM for about $700. That's what I have, its great.

That's good to know that you can make them fit. I'm assuming your LBS installed spacers on the non-drive side crank because there is no way I have the clearance. But maybe I'm missing something here.

Based on this post from Open and the comments, the Stages L doesn't fit without some modifications.

I've got that cinch PM on my mountain bike and it's perfection.

That said I now have a fat bike for snow racing, gravel bike, mountain bike. Same cleats. That means.....those new SRM pedals are looking mighty nice. Until I smash them in the rocks on the MTB of course :/

I have also ridden MTB and gravel races with my vector 3 pedals. I only use them in races where hike a bike is unlikely. Road shoes and mud don't play well together.

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I have a stages on my Lauf True Grit. It's good enough for me for gravel biking. For my road and tri bike I use the favero assioma pedals which I like. Not interested in modding those work with mtb pedals. For me, the stages is close enough for gravel riding. I feel like with gravel riding I rely very heavily on RPE since gravel riding tends to beat up my entire body more than road riding.

Nope, not missing anything, a spacer was installed.

This.