Anyone have a good reference for targeted % of FTP given the duration of the event. Of course, 1h is 100% of FTP. I am interested in what % of FTP targets across the ride should be for >1h efforts, specifically for activities with total durations of 2h, 3h, 4h, 5h, and 6h marks.

It seems those that train with power meters that know their FTP and do long efforts could pool metrics together and arrive at some rough ranges here for duration of event against their FTP.

Specifically, I'm training for a 100k ride with a 1 hour climb in it. I am looking to shave about 3% off my previous years' time of 4h7m, but I don't have accurate power data from then so looking to pace myself this year around a target of what my currently tested FTP will be on race day. I know the metrics are still only a guideline.

Your Critical Power (CP) curve will be unique to you. You can get a predicted power curve by using a calculator that implements Monod's Model (or others).

Cycling Power Lab

I haven't found the CP curve to be that helpful after ~2-3hr though because you end up taking breaks/stopping at rest stops.

You should be able to use Golden Cheetah or a number of other training with power apps/programs to generate _your_ CP curve for the efforts you do have.

FTP is not the power you can hold for a hour. This is the defintion that gets oft-repeated. The actual concept is that it's the power you can hold for a long time, in the range of 40-90 min say depending on your physiology. We're all different.

When I'm trained up to endurance efforts, I can ride at 75-77% FTP for 5-6 hours. I can sometimes knock out a 2 hour group ride at 88-90% FTP. I've done 100% for 70 minutes.

Part of the answer to this is knowing/learning what you can get away with based on how resistant to fatigue you are. I usually ignore the adage of not going out too hard, I tend to go out hard and see how it goes. Sometimes I pay the price at the end, sometimes I have a great day. But so far I never fail to get it done on a long ride, even if I go out too hard.

I'd say do test rides and discover what you can do prior to your event.

If I had a 4 hr event like OP, I think I'd personally be shooting to ride it at 80% FTP.

It's likely the fastest time will not use uniform power throughout the ride. You'll want to go harder on the 1 hr climbing section. Is this a solo ride or will you be able to draft?

edit: If it's a mass start event, aiming for a target effort is not really meaningful. You'll want to find a decent group you can ride with and stay out of the wind as much as possible. Drafting is key so you need to do whatever it takes to stay with your group on the shorter hills leading up to the main hill. That may mean going well above FTP for short periods.

Once you hit the main hill you should be riding as close as you can to FTP. On the main hill, if it's reasonably steep, there will be minimal draft and pacing will be important. I would ride at 90-100% FTP but if you don't have many miles in your legs you might start the hill at 70-80% and see how it goes. If at the halfway point you're feeling OK you can pick up the pace a little. Once you crest the hill find others to ride with and stay out of the wind.

I've ridden as hard as 93% over 2.5hrs (normalized power), yesterday I did a trainer ride at 80% for 2.5hrs (mostly 82%). I'd concur with heathpack that 80% is probably a good target for longer duration rides, once you get over 83% you start getting into sweet spot, and that gets a little harder to maintain for too long (and if you see the chart on this page, it suggest sweet spot for up to 3 hrs https://fascatcoaching.com/tips/how-to-sweet-spot/).

If you're observing power as you go, I'd make sure your head unit is showing normalized power (and intensity factor), it'll give you a better idea of the effort as you go along so you don't blow up too soon