Is power data useful for MTB training?

Hi team,

I’m interested to know if you have a power metre on your MTB, and if the data is as useful as the road - I was told that MTB power data is so inconsistent ( think XCO / Marathon ) due to the terrain, that there is little benefit to tracking power off-road.

Thoughts?

I have a power meter on my MTB. I find it not that useful for pacing during the rides but for post ride analysis and for tracking training stress just as useful.

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Another mtb power user here and I find it very useful.

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I have one and I think it’s useful. I mostly use it for tracking training stress, but am going to try to start using it in an XCM for pacing the climbs, which I currently do with HR.

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A power meter is just as useful for MTB as it is for road.

Depending on the terrain, running a higher average for your power display on the headunit can be helpful, but that is about the only change I would make.

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I really think its useful. Especially in Marathon. Used it for a race in NC last year that had several long climbs and it was great, especially with some BestBikeSplit homework

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What power meters are suggested for MTB bikes? Crank or pedals? I have vector 3 but there road bike style…

Quarq

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There are no pedal based power meters on the market for MTB.

Common picks for MTB are Quarq (crank spider), 4iiii (crank arm), and Power2Max NGEco (crank spider).

Quarq all day long

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I have to agree with the Quarq recommendation, they own the patent for shear design, used by many other companies, even SRM.

For those that prefer to read: https://titanlab.co/are-all-powermeter-spiders-just-quarqs/

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I have a 4iii and use it to track stress, also for pacing on longer climbs. It was quite cheap and I would buy it again.

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I have Stages and 4iiii. Both okay powermeters but with the main difference that Stages is impossible to calibrate against another powermeter. 4iiii has the possibility to set scale to match another meter, in my case an indoor trainer. I haven’t had any issues except power spikes when I hit the pedal or crank in rocks. If you’re doing any structured training outside a powermeter is necessary I’d say. Going by RPE/heartrate is just some type of in between solution.

I would however recommend either Quarq or Rotor 2inPower for more accurate dual leg readings

Power2max Eco. It has worked well and had a good price point. I like being able to track TSS with outside rides and analyze race data to see how my effort shaped up against training.

Quarq and PM for MTB is great for all reasons above and especially for post race analysis

Yes, totally useful. Knowing what kind of efforts are necessary for whatever riding/racing you want to do is always going to be useful.

The thing that is a little trickier is TSS. The power meter isn’t going to adequately capture the stress on your body from, for example, hauling a heavy enduro bike down a tricky descent.

I think MTSS is probably a holy grail for some people and I’m sure there are some smart people working on it. My guess is that to really crack it we’ll need to bring in data from another source (possibly something like the shockwiz), or at least get a three-axis accelerometer on a powermeter (assuming that most PMs have only a two-axis to measure cadence) in order to measure g-forces. How that correlates to stress on your body is a whole other question, though.

When I go for a hard MTB ride with a lot of aggressive descending I usually assume my ‘actual’ TSS is ~5% higher than what gets calculated from my power data.

I use a 4iiii on an XT crank arm on my Santa Cruz Bronson. I am in the market for one of those fun ‘downcountry’ bikes. I’ll either put another 4iiii or a quarq on that. I have a quarq on my CX bike.

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it’s really useful especially for any section where you’re attacking or making a late race move. also, sustained climbs where it may not be as erratic as normal. You’re still going to gain insights from normalized power over different durations and how it compares as you ride different courses. Also, while you can estimate TSS and such from the HR strap, having power numbers is more beneficial IMO.

It would be similar to saying: no need for power in crits. For same reasons, it’s really useful.

time to place an order! :wink:

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Yes they are useful. Not as useful for pacing but good for TSS tracking and post ride analysis. Quarq for me and I’ve been super happy with it.

I hope that smart people are working on it. I was just looking at 3 of my own rides, all within a couple of months of each other, on the same bike a Spec Epic with P2M power meter, and all 3-4 hours long. The first was a road ride where my NP for the ride was 270W and I’d gauge it as medium hard. The second was a gravel race on rolling terrain with NP of 245 and it was very difficult. The last was a MTB race in the Shenandoah mountains where I just about died at the end and my NP was only 230.

Maybe for now tracking stress with TRIMP would be best if you’re focused on MTB,

Yep, that’s exactly right. Applies to CX as well. There is one course around here (possibly my favorite) that is not technical and is full of heavy, false flat sections that make you want to die. I have finished 50-60 minute races there with 90+ TSS. There is another course, which I also love, that includes the biggest run-up I’ve ever done and a ton of technical riding. I usually finish with TSS in the mid-30s. Totally different, just as tiring.