If a climb is only 30 seconds to a few minutes long, you can probably smash it, go in the red, and make it to the top while still staying on top of the pedals. When climbs get longer however you can employ the same technique but you will start to suffer and slow drastically before you hit the top. To get your best time to the top of a climb it’s important to properly pace yourself. The guys at GCN do a test in the video below to show the differences pacing can make. They use a power meter but you don’t necessarily need one. You can keep an eye on your heart rate keeping it lower when you first start and watching it climb steadily to your max toward the top of the climb. If you just ride based on effort level, start at a pace you know you can maintain for the climb and then go a little bit harder and reassess if you can make it to the top. Do this until you are unsure and stay at that level. And then when you get near the top, up your level of exertion again. As with anything, the more you do it the better you will get at it. You will know what your limit feels like and what you can and can’t maintain. This will get you to the top the fastest.