My first 10 mile TT

Today I did my first ever 10 mile TT! Seing as all organized TTs are canceled due to COVID-19 I figured I’d just do one on my own.

I’m currently in Sustained Power Build LV Week 3 and had Galena +1 on the menu. Was feeling good, so I figured I’d go for a 10 mile TT as the first interval and just see what happens after that. Needless to say I that left me pretty fatigued. So instead of the remaining 2x20min @95% I did 2x10min.

Thought I’d share the results of the TT and see what guys think are possible improvements:
Distance: 10 mile (16.1km) in 27:14
Speed: 22mph (35.5kmh)
Power: 237W (94% of upright FTP 252W)
Position: Road bike (Giant TCR) using clip on aero bars
Gear: standard road kit, no aero helmet/skin suit/over shoes
Tires: Schwalbe One V-Guard with butil inner tubes
Weather: about 20 degrees Celcius with a 10mph (17kph) NE wind
Road surface: 90% smooth tarmac, 10% somewhat smooth
Course profile: Flat, no road crossings or stopping lights
Note: had to slow down and go offroad once because a tractor was blocking the road.

Really stoked at the results. Didn’t expect to go this fast considering the wind and being in the middle of a training block. I even got a season power BP of 28 minutes @ 238W and that’s done in the aero bars. My upright FTP is currently 252W. So I held 94.4% of my FTP for 28min in the TT position.
This is my first Base/Build cycle using Trainerroad and I can honestly say the results so far have exceeded my expectations.

Couple questions:

  • Is holding ~94% of my upright FTP in the aero position for 28min considered an acceptable loss, or should I do more training in TT to lessen the gap?
  • How much do you think I would could gain in speed on this course using lower rolling resistance tyres, latex tubes, over shoes, TT helmet and skin suit?
  • What do you think of my pacing? Should I have maybe done more of a ramp up or down? Roughly first half was tailwind, second half was headwind.

23-06-2020 Update in post 30:


Hard to tell on the first two, too many variables at play. Sound advice is replicate conditions of your main events as best as possible. If that means riding in an aero position then you should train (some) in the aero position.

Second point, a lot depends on the conditions, but everything will save you time, so invest where it makes sense to invest, and with a helmet testing is key because what’s aero for me might not be aero for you. Some googling will help narrow your focus, but the key is going to be trying. Skin suit, get one that fits really well, flapping kit is a killer.

Pacing looks good, looks like a nice negative split! Congrats!


Very nice job for your first go at a TT. FWIW, there is no reason to accept lower FTP on TT bike than on Road bike. There was a point where I rode my TT bike so much my power was higher in that position than the road (Upright).

For a 10 mile TT, FTP isn’t the right power target. You should shoot for something more like your max 20 minute power which should be significantly higher. For example, when I was TTing a lot my FTP was 235w but my 10 mile TT power was 255-260 with a few amazing days over the years 265+ at peak fitness. That is roughly 110% of FTP. On a flat course we race several times a year that works out to 21:30 - 22:30 depending on wind.

Even pacing is not likely the optimal way to do any TT course, but it is a very good place to start and a very good skill to have. Looks like you did well keeping constant effort. When you get fancy try Best Bike Split as that algorithm optimizes power per course and conditions to optimize for best time.

Gear - A good skin suit and TT helmet will save a few watts. Tires, tubes, overshoes all add up. But don’t get wound up thinking gear. Just get into the hurt zone and put down the watts.

Chapeau on a nice first TT.



94% isn’t bad for a first effort, but if you wanted to race TTs or triathlon you would certainly want to get it closer. Some of that could just be training more in the position, could also mean position changes. Clip on bars on a road bike is rarely going to give you an optimal TT position either aerodynamically or ergonomically, so that could well be costing you some power. For reference, the people I know who take their TT training seriously typically have minimal to no difference in threshold power between upright and TT.

Maybe 1-2mph “free” speed to be had, depending on just how non-optimised your current setup is. I.e. if you’re on Gatorskins and loose fitting clothing there’s a lot of easy gains to make. If you’re on GP5000s and a nice snug jersey and bibs already then not so much to gain.

Pacing looks pretty good. Nicely done!


Easy stuff!

1.) Switch to Conti Grand Prix 5000. 10W+ (see
2.) Switch from butyl tubes to latex. 3W (see
3.) Change your pacing strategy. You held constant watts but your commentary indicates it was a windy day. A better pacing strategy is probably going a little harder into the wind and a little easier with the wind. (see for one free race analysis if you create an account)

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There is a lot of time to be gained here…for reference, I just went and looked at some of my tri bike splits. For a couple of OLY distance races, I went ~24.5mph on ~220-225w.

Now, a lot of that will come from using a TT bike vs. a road bike w/ clip-ons. As noted above, it is very hard to optimize your position on a road bike for TT gains (but it can be done). That said, there is definitely some low-hanging fruit that you can easily pick.

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Thanks for the feedback guys!

The GP 5000 and latex tubes were already on order. Should be arriving on wednesday.
Next upgrade will probably be a skinsuit followed by a helmet. Was thinking about the Giro Aerohead. Do any of you have any experience with that helmet?

I’ll continue to work on my power in TT position to bring it up closer to my upright FTP. I’m also slowly adjusting my position to get lower in the front. Taking it 0.5-1.0 cm at a time.


The type of helmet is very dependent upon your head position. Too long a tail becomes a sail if you look down (and the rear end lifts to your detriment).

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Helmet aerodynamics are very individual and it is impossible to tell which one is best, or even, better for a given rider over another.

That said, there are several “safe” choices that generally test well for the majority of riders. The Aerohead is one, as is the older Giro Advantage. The Louis Garneau P-09 also tends to test well.

So if you can’t test, the Aerohead is a solid choice.

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Nice job! As others have stated… a ten mile TT should be slightly over your current ftp (60 min power) and similar to your 20 min power.

I created a 30k strava segment near my house so I can test on but remember to try and perform the test in similar wind/weather conditions.


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Well done!

Yes :slight_smile:

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As an occasional tester, in the couple of weeks before an event I’ll do a few extra aerobic rides (pettit, taku etc) and try and spend longer and longer in the aero position at different cadences. If I can do ten minutes on the turbo, the 25 or so minutes on the road is usually doable at more power.

My top tip: If you want to get good at TTs move to the UK, you can do three or four time trials every week!

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Good work on your first TT. I did my first last year and was considerably slower than your’s so well done.

Sounds like you’ve got some easy gains to come from your kit and tyre changes - would be good to hear back on how your times improve. :+1:t2:

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I also got this interest in recent months …

You can definitely get faster even on road bike - 23.5-24 mph should be doable on flat no wind course at that power. I say that from my experience on a 7 year old non aero road bike with redshift bars, two bottles, frame pump, top bag, varia… (i.e. not a stripped bike) and a not extreme position testing on flat rail trail in the 240 range.

If your road jersey is not super tight, finding one that is may be cheaper and more versatile than skin suit. This was a big gain for me. I also seem to be a little faster with smooth arm warmers but haven’t tested that explicitly. It may be an ok poor man’s approach when starting out.

Totally agree with other advice above as well!

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My plan is to buy a helmet, see how it fits me and the aero position. If it’s no good, I’ll just return it and try the next one. Hadn’t thought about the Louis Garneau, thanks for putting that one on my radar!

That’s exactly what I did, created a 10 mile segment in Strava. That also makes it pretty handy for comparing results.

I try and spend a lot of my time in the TT position on my aerobic rides. Occasionally I also try and do that for a hard interval in a workout. Most of my training is upright though.
Man you’re lucky in the UK. So far I’ve found about 5 TTs here…for the entire YEAR :frowning:

Thanks! I’ll try and update this post when I’ve made improvements. Tyres coming in today and I’m not far off from ordering a Skinsuit.

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One thought that has not been covered is average power v Normalised power. In a TT you need to be putting power down all the time so the aim is to get NP and AP to be equal or as close possible.

Not sure what your was in the race. I agree re exceeding FTP at least for a 10 mile event.


Yep - though good to start a little bit under, finishing a little bit over.

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Agree, I think I should be able to get close to that speed/power on my road bike. The speedsuit I’m eyeballing (Velotec) is cheaper than a jersey+bibs, so well worth the price. I’ve heard people even find a suit more comfortable to ride in.

Not at the moment you can’t unfortunately :pensive:

your pacing is insanely good for your first TT!!! like really good!

yeah probably work more on TT bike, 94% is a bit low if you want to really focus on this

nice work!

oh ps, gain speed with tailwinds also :wink:

wrote this article that might help you out, let me know if it does!