 What if I told you that that lockout lever that you have on your bike for both your front fork and your rear shock is largely unnecessary and doesn't actually improve your bike's efficiency? It's certainly a bold claim considering that it's pretty much common knowledge amongst mountain bikers that bobbing suspension robs you of power. And no, I'm not talking about keeping your suspension open on a rocky, rooty climb to maintain traction and a consistent power output. I'm straight up talking about a smooth paved road where that suspension is doing nothing for you but bobbing up and down. Certainly in this situation, suspension has to be costing you power, right? Oh, for sure, dude. Also, the eight beers I had last night probably didn't help. In this video, I'm going to be taking a look at the research to get to the bottom of this question. And I was surprised enough by the results that I actually put this question to the test myself and I'll be sharing those results with you at the end of the video. So without further ado, let's jump into the science on how suspension affects bike efficiency. There are two possible ways that leaving your suspension open while riding on a smooth surface could be less efficient. It could be less mechanically efficient, meaning that at the same power output, you're riding at a slower speed. Or it could be less metabolically efficient, meaning that your body has to work harder in order to ride at a certain power output. This study on the effects of suspension on the energetics and mechanics of riding bicycles looked at both these possibilities. In their first test, subjects rode uphill on a motorized treadmill on a road bike with steer tube front suspension while oxygen consumption and mechanical power output were measured. What they found was that the difference in both metabolic and mechanical power in both the sitting and standing trial was not statistically significant between the compliant and rigid conditions. So no difference in efficiency between having the suspension locked and unlocked, and this didn't change when they had the subject stand, which you would think would have more of an impact. Of course, this first test was done on a road bike with steer tube front suspension. And yes, if that sounds like the system that Specialized uses on their Diverge and Roubaix, then you'd be correct. But is it really all that surprising that an otherwise rigid road bike with a small amount of suspension right at the steer tube would yield these kinds of results? I don't think so. Fortunately, they did the same test with a full suspension mountain bike. What they found after test two using a full suspension was that again, the mechanical power required between the two conditions was identical. And the metabolic power average was very close, close enough that results were not statistically significant. And this goes for both the seated and standing test. All right, now we're getting somewhere. And I got to be honest, after seeing these results, I was a bit skeptical. It goes against the grain of what the cycling industry tells us and, quite frankly, what our own intuition tells us. Mashing up a climb with squishy suspension sagging under you with each pedal stroke simply feels slower. I will say, though, that just because something feels slower does not necessarily mean that it actually is. A perfect example of this is a narrow tires set to a high pressure. Riding 23 millimeter tires pumped up to 130 psi may feel fast, but we have data now that indicates that this is not actually the case. That's a topic for another video, but for now, let's get back to the science on suspension. Is there further data to indicate that the lockout on your suspension is not actually improving your efficiency? This study on the energy cost of riding with shock absorption systems had subjects perform grated tests on a full suspension, hardtail, and fully rigid bike. What they found was no difference in VO2 between the three bicycle types. They concluded that there is no significant difference in energy consumed by cyclists riding bicycles with and without suspension. The claims of many competitors who still prefer front suspension bikes or hardtails could be related to a possible significant energy loss that could be present at powers superior to 250 watts, which is what was tested here or when they stand on the pedals. Now, this study was done back in the year 2000 when, quite frankly, full suspension platforms were not up to the standards that they are today, and yet they still came away with these results. This was back in a time when most cross-country racers chose hardtails, which is why they made that closing statement about why racers might be choosing hardtails over full suspensions. Fast forward 20 years, though, and most cross-country racers have left their hardtails behind. That being said, though, I wouldn't even look to what most people are doing as evidence that it's faster. Well, yeah, not what everyone is doing, but if you're faster than me, then the only explanation is that you've got some superior piece of equipment on your bike and I'm prepared to whip out the credit card in order to fix that. Again, I go back to tire width and pressure. 20 years ago, you may be forgiven for thinking that narrow tires pumped up rock hard were faster, but since then, we've learned a thing or two. And 20 years from now, there's probably some piece of equipment that we're using that will look back and go, what were we thinking? All right, back to suspension again. These are not the only two studies coming to this conclusion. For example, this study found no difference in climbing speed and energy expenditure between a full suspension and hardtail, and this study comes to a similar conclusion as well. This review of many studies on the topic states that evidence in the literature suggests that cycling-generated power that is dissipated by suspension is minimal and probably negligible on most terrain. It simply doesn't appear from the literature that riding along with your suspension open is less efficient than locking it out. And this is the part of the video where I say the research is limited, but all the studies seem to be pointing in the same direction. The difference here is that this is actually not that difficult to test out on your own. You can do it in one ride, which is exactly what I did. I went to a local paved climb and rode up and down it 12 times to get some data points. Now, bear in mind that while these were all done on the same day with relatively low wind, these are not perfectly controlled conditions, and the sample size is just one. Me, so take these results with a grain of salt. I more so just wanted to see if I could replicate these results that I was seeing in the literature out in the real world. Doing your own test, so this is basically turned into a GCN does science video. Watch, next week it's going to be do fenders save you from looking like shit at your pants. The bike I used for this test was my Niner RKT9 RDO Cross Country Full Suspension with a Fox 34 step cast fork and Fox Float Shock. I used my quirk power meter to collect power data. For this test, I alternated between locked out and open. So six of the runs were locked out and six of the runs were open. I also did half the run seated and half the run standing. And of course, I rode at the same power output for all the runs at 250 Watts. Here's what I found. My run times are all recorded here and just from a quick glance, you can see that they're very similar, but we'll get to that in a minute. I was able to keep my power for each run very consistent. On only three of the 12 runs, did I not hit exactly 250 Watts and was one watt off, but taking into account all three runs for each condition produced an average of 250 Watts across the board. And perhaps somewhat surprisingly, these produced pretty similar results across each of the four conditions. Here's what my average time was for each condition. Locked out seated was three minutes and 30 seconds. Open seated was three minutes and 31 seconds. Locked out standing three minutes and 32 seconds and open standing three minutes and 32 seconds. And then of course, the most relevant bit of information for this video, the average of all the locked out runs versus the average of all the open runs. 331 and 331. It simply doesn't get any closer than that right there. Interestingly enough, the seated runs appeared to be two seconds faster than the standing runs at the same power. And I imagine that this is probably due to the increase in aerodynamic drag of the standing position, but there was no difference in average run time between locked out and open suspension when I was standing. This was enough for me to say that for me on this particular bike, yeah, same power is going to equal the same speed regardless of whether the suspension is locked out or open. Now, my bike has a pretty solid pedaling platform and it's an XC race bike. If I had done the same test on an Enduro bike, what I have gotten the same results, maybe I really can't say for sure, but given the fact that the difference between locked out and open wasn't a small difference, but actually no difference. I can't see any reason to think why bumping up the suspension travel would change that. Perhaps some of you with bigger bikes can test this out for yourself and tell me if I'm wrong here. One last important bit of data to point out. I was wearing a heart rate monitor for this test and this can give us an indication of the cost on my body in each condition. This data does raise a few questions. My average heart rate for the locked out runs was 134 and my average heart rate for the open runs was 137. Now, again, this is not nearly enough data to make any sort of conclusion, but it is interesting nonetheless. One potential confounding factor here though may be the fact that I started with the locked out effort and my heart rate tended to rise throughout the course of doing these efforts, which may be skewing my heart rate up for the open runs. So what can we conclude here? Well, let's see about that. You didn't get the KOM with the suspension open or locked out. So absolutely nothing. And again, you've wasted 10 minutes of my life. Again, I want you to take the data that I got on myself with a grain of salt, but given the literature that we have on this subject, I would say that locking out your suspension does not improve your bike's efficiency. Sure, a locked out bike feels faster, but just because something feels faster does not necessarily mean that it is. What does this mean in terms of how you should ride? Well, first things first, if you're in the market for a new mountain bike and you're deciding between a full suspension and a hardtail, or maybe you already have a full suspension and a hardtail and you're trying to decide which one to use for a particular race or ride for that matter. The efficiency of the bike should not be part of your decision making process because a hardtail is not going to be more efficient than a full suspension. And when you take into account all the roots, rocks and undulations that you come across when you're mountain biking, the full suspension quickly becomes the more efficient option. The only advantage that the hardtail has over the full suspension is that it's lighter, and this may be significant depending on the course, but I would say that it would probably have to be a pretty smooth course with a lot of climbing. Finally, as far as how to use your lockout when you're riding your full suspension, when you hit a road section, I wouldn't just not use it. The psychological boost that you get from feeling like your bike is faster probably does something for you, so if you have it, use it. That being said, I wouldn't be overly concerned with constantly locking and unlocking your suspension when you're riding on trail, especially if it's just another thing that you have to think about and taking away from your focus on the trail. Because at the end of the day, that lockout is probably not doing a whole lot for you. Thanks for watching. If you enjoyed this video, be sure to give it a like, subscribe for more science-based cycling content just like this, and share this video with your cycling friends. I'll see you in the next one.