I have a TT coming up in about a month. I’m shooting for a time of 35 minutes. It’s out and back, on rolling terrain. There is often a headwind on the first half, but harder uphill sections coming back.
I’m trying to figure out what average watts to aim for. How would I go about this? Would this be in the range of 100% FTP? There are three downhill sections where I might not be able to reach my FTP without spinning out. I’m fairly heavy and can reach high speeds downhill. Should I consider those sections like little recovery sections and just focus on max aero position?
For a TT of that distance/time, I’d just go out and figure out pacing when I’m doing my practice runs. Go out and try ~30 minutes at ~100% of FTP in TT position. Do a couple of those and make it a quality threshold interval day. I’d make those my dress rehearsals (all equipment) at least once a week between now and the race. My general approach to figuring out TT pacing is to guess at the target watts and then do an effort that is about 85-90% of the duration. Adjust and try again if wattage is too high or too low. I don’t want to be trying to do higher watts on race day compared to training, but I know I’ll be able to find the extra duration at my training wattage with race day motivation. And I’m not sure how “rolling” the rolling terrain is, but I try to push about 10% over wattage target on the ups and 10-20% under target on the downs (if it’s shallow enough to keep pedaling). The only place I’ll go more than ~10% over target is at the start, the turn-around, and maybe a couple quick/steep spots or coming out of really slow turns. But those efforts will kill me if it’s more than a handful and I generally cap it all at 10% over.
Mywindsock.com is another useful tool to help lay out a pacing plan. The basic principle is that you should target a higher wattage when you’re riding slow and a lower when riding faster, just as been suggested earlier. A tool like Bestbikesplit or Mywindsock is useful dialing in the optimal amount.
I usually hold all TTs regardless of distance at 92% max HR, maybe pushing up to 99% in the last mile. 95% FTPwise. It’s probably why I’m too stable in TTs timewise though.
I have helped with some high level TT pacing strategy. As someone else suggested, it’s complex but bestbikespit is very advanced and very accurate if you provide it good data.
The basic pacing idea is figure out your normalized power (NP) for 35 minutes. Probably about 5% above your FTP or something. Remember aero/wind is exponential and gravity is linear. What that means in high winds or downhill back off slightly below FTP and uphill go about 5-10% above FTP depending on duration and steepness. The rest of the time you should try to be closer to FTP but downhill obviously be safe. Ultimately you want to try to average that NP but you also don’t want to blow up. Even with pros, the strategy is usually rather simple like those rules but can be simplified from bestbikesplit suggestions.
I’m definitely checking those out! The race route is near my home, so I can go ride it any time. I’m going to play around with these apps and do some trial runs.
The apps may give better advice, but I figure you’d want to drill it on the climbs of the rollers and push hard and steady into the headwind. I’m pretty sure you get the most ‘bang for the buck’ by putting in bigger watts into inclines and headwind relative to declines and tail wind
Basically calculate your IF (percent of FTP) based on the time.
20 minutes – 1.05 IF
1 Hour – 1.00 IF
1.5-2.5 Hours – 0.90 IF
2.5-4.5 Hours – 0.80IF
4.5-16 Hours – 0.70 IF
They recommend negative splits, so going a little under IF in the first half so you have energy stores at the end when you need them. That worked pretty well for me on my last time trial but still felt like maybe I could have gone a little harder at the start, but I’ve heard that’s the biggest mistake everyone makes in TTs.
It feels right pushing harder into headwinds (since you are slowing down) but since wind/aerodynamics are exponential when you go against the wind you push much harder and gain very little. This is where backing off on your power slightly and saving it for the hills can pay dividends. Also it feels a bit wrong, but fun, but you should push harder in a tailwind
Going fast with a tail wind cannot possibly be a bad thing!
I do wonder about the effort distribution on hills though. The prevailing advice seems to be to push a little harder when ascending and focus on aero on descents (below threshold is ok).
However, this doesn’t take the rider size into account. Physical size massively affects aerodynamics, and weight affects the power needed to maintain speed. I’m quite large and heavy. When I ride with friends or with a group I always end up going faster than most on descents, even without trying (especially if I get in a good aero tuck). On the flipside, I’m virtually guaranteed to get dropped on any and all climbs.
So, if we compare two vastly different riders on the same course, wouldn’t the strategy change for each of them? I’m imagining a small and light climber, vs a large and heavy diesel-type rider.
The climber would push a bit harder going up, because the time gain for them will be substantial. Then focus on aero going down, to compensate for the relative light weight.
Wouldn’t it be better for the heavy rider to just get up the hill below threshold and smash it on the descent where they already have a speed advantage?
Fast with a tailwind is what we live for We are specifically talking about TTs here the basic fundamentals remain the same regardless of rider size but the actual prescribed wattages or percentages of FTP change based on the aerodynamics and speed of the rider. Obviously aerodynamics matter a lot more at 50kph than 20kph.
Best bike split provides the exact targets better but it is complex and no the bigger rider still benefits from pushing harder up hill than downhill in fast / short races.
The physics regarding pushing uphill vs pushing against the wind don’t change based on rider size. Where things can change is when you are not close to FTP in your effort. Meaning 30min TT unless you get some place dangerous or seriously steep downhill you are pedalling around FTP the entire time. Longer events, group rides or fun rides the difference between tucking and pedalling is complex to evaluate which is going to be better for any specific rider, and with others we know drafting plays a big role.
Just because you are slow going uphill (me too) it’s still usually the best place to give a bit more power for best finishing times. Now in reality when going uphill especially with others you and I are pushing way more than 10% above our FTP in many cases to keep up so we are on the verge of blowing up and this is not likely the fastest scenario as we then coast across the top and rest on the way down and this whole dynamic is not as well understood as far as I know. Doing what you can to keep up is likely the best.
The math is very clear and accurate for TT racers going all out in shorter efforts. For typical rides for you or I this is more likely a bit of trial and error and seeing what works for you. Your intuition is likely right but giving a bit more on uphill is still a good idea but not killing yourself on the uphill way above FTP.
Yeah, that all makes sense. It occurred to me while reading your excellent comment, that indeed the descent type would make a difference in approach. The hardest part of the course is two hills in succession with a long smooth descent going out, which becomes a long smooth ascent on the way back. The descent is long enough that I end up in my highest gear, and even approach my threshold at 100 rpm becomes difficult. (basically I’m accelerating the entire descent). On this section it makes perfect sense to just chill a bit since forcing myself to maintain threshold affects my form and stability.
This also means that it makes sense to push hard on the shorter and steeper ascent right before it. Basically, the long descent becomes a a few minutes of recovery (before hill 2).
Hill 2 is a completely different beast. The ascent is much longer and I’m not really able to hold above threshold the entire way. Also, this one does not have a descent on the other side. It flattens out for about 500 meters where the turn-around/half-way is. For me this is one of the most difficult parts of the course. There just isn’t a natural opportunity to recover (it’s also usually the windiest part). Here going above threshold would risk bonking and making the return a journey through hell.
Anyway, lots to think about. And I will definitely experiment with the apps.
Incidentally, I’ll be doing the race on a standard road bike with no aero equipment. The race has a Merckx category for all us TT equipment impaired riders. In the spirit of the category, I’m even considering doing it on feel, leaving the Garmin in my pocket. Not sure I’m brave enough for that though, but it could be a nice throwback experience of my youth. Yes, I’m old.
I am old too and if you start practicing now you could for sure do it by feel/RPE and it might even be more effective, especially since it sounds like you have a good strategy. Sounds like a fun race and a fun challenge, enjoy it…
