Good morning all. I’m looking to find out how I can translate my road FTP to gravel FTP. I mainly ride road/indoors but I occasionally ride gravel. I signed up for a gravel bike race this year and wanted to know how to translate my road ftp to gravel. When I do ride gravel, my power drops a lot, almost a zones worth. If that’s the case, should I just use that as my guide? My current FTP is about 280. When I go gravel riding, I want to be able to adjust my FTP on my head unit so the numbers I need to hit reflect what my “gravel FTP” is. If anyone is able to assist, please, let me know. PS-ChatGPT says id be around 250. Thanks in advance.
Never heard of such a thing. Same/similar power meter? It’s somewhat common losing power going to a more aggressive position (like tt), but normally people aren’t doing that for gravel. Maybe it’s really chunky gravel and fatigue is related to that? you can adjust workouts up or down as needed, but TR ai is just going to see the watts.
I would:
Calibrate both
place each bike on a trainer and measure the FTP vs the trainer’s power to benchmark
If your power meters are different, adjust the PM through its apps setting to match power in the offset.
if step 2 is not available, I would sell a power meter and attempt to get two of the same PMs that you could normalize with one another. Believe it or not, some of the less expensive PMs can handle this better than the most expensive which can read highly inaccurate on some models.
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Are you using the same bike on road and gravel, maybe just different tires? Are you using the same PM for both road and gravel? If different PMs, do they read pretty much read the same?
Lately I’ve been riding the same bike on road and gravel and don’t see any diff in power between road surfaces. I’ve done 20min FTP tests on gravel and on paved surfaces and they pretty much agree.
Your ftp should be the same on both no?
How are you measuring that it is different?
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This question is a bit confusing. Are you using same/different bikes and same/different power meters. Are you simply comparing your efforts after your gravel rides to your road workouts?
Consider this - gravel rides and events often have different power profiles depending on the course profile and terrain. Depending on where your ride it can be unreasonable to expect the power curves for your gravel rides to resemble your road rides unless you are on some very smooth terrain. Where I’m at, in California most of the terrain is punchy with a lot of steep, technical descents for the most parts. We don’t have much mid-west style gravel out here.
When you compare efforts, I think it’ll be helpful to compare your steady efforts on your off-road rides with what you normally do on the road or on the trainer. Those should reasonably line up as far as power output goes.
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I bet it’s related to road surface and decreased efficiency. If you run sufficiently large and low pressure tires on your gravel bike, you SHOULD find that your efficiency and effective FTP improve. The extra vibration and vertical movements takes energy to absorb, and if your tires and/or suspension aren’t doing it, your body is. This is also why higher volume and lower pressure on road tires tends to reduce fatigue and improve power and speed on rougher road surfaces.
How are you determining that your FTP is different? Is it just that it FEELS different? That you feel less durable or able to hold higher power numbers? This would be expected behavior on gravel. The road/trail surface definitely has an effect on overall fatigue and makes it harder to hold bigger numbers. it’s not that your FTP is “lower” per so but that you are exhausting fuel stores not only with your legs but with your arms and shoulders and core and all the other parts of the body that are recruited in stabilizing the bike on an uneven surface.
You would never do an FTP test on a fire road or single track.
Bike fit between the road bike and gravel bike could affect power, but assuming it doesn’t, some people seem to be less efficient depending between climbing, flats, pavement, dirt, singletrack, etc…
You could toss the gravel bike on the trainer and do some intervals to see if it’s a power meter difference, fit difference, or whatever. Beyond that, you can ride to RPE instead of power for your zones if it’s really that much different for ya.
Thank you all for the input. I realize my question may have been vague or not directly what I am thinking. A lot of you said the same thing though, RPE is going to be different. Firstly, my power meter is the same for both bikes (Scott road, Felt gravel, both with favero PM). I have used both bikes on indoor trainer using my kickr core and power is the same. I guess it would come down to the fatigue aquired while riding on gravel. I have done some pretty flat/smooth gravel and I can hit my z2 power with ease. But going for my threshold power, it feels like V02. My guess is that is due to the terrain being perhaps a little chunky compared to flat road. Im not an elite racer so I’m not looking to podium, but I want to be able to ride like I can on the roads. Should I accept the fact that I may not be able to keep up my Z4 power on chunky gravel as easily as I can on the road?
Zero difference between these two for me.
Sounds like you have a Power Meter calibration issue between different bikes.
Kinda depends on how chunky is chunky and what your bike setup is. If you are getting beat to death on the bike, that’s taking a physiological toll (just like descending is work even when not pedaling) and can certainly affect the sustained power you are putting into the pedals. But I wouldn’t just accept it will always be lower. There are things that can be done to narrow/close the gap. Bike setup (particularly tire volume) can be the difference between putting out smooth watts and just getting banged around burning bunch of energy thrashing on the bike. And some of it just comes with experience/practice. Just like riding cobbles, there is an art to efficiently pushing big watts through heavy chunk. Don’t fight the bike, be light and supple on the saddle and bars. Much like MTB technique, heavy feet and light hands are good. And if most of your riding is on really chunky terrain, consider suspension or even riding a MTB. There are gravel races where I ride my XC FS MTB and it’s like a cheat code on really heavy gravel sections.
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