Assuming you have found the optimal fit on both, is your FTP higher on your road bike ?
I understand the concept that a loss in power on a TT bike is largely compensated by a more aero position, but do you have a lower FTP on the tri bike ? I believe this relates to the hip angle/power thing.
Today on the Computrainer, I was doing 4x10’ @FTP. My HR would slowly raise and stabilize for the 8 minutes, and I would sit up the last two, stay at the same power level, but my HR would drop 3 beats or so. I assume that I could probably raise my power a little, in other words, on the same effort put out more power.
Do others see this ? How many watts difference do you believe there is ?
I will continue to find that right balance of generating watts and stay low/aero.
Yes I have a difference. I trained last winter on my road bike. When I bought my tri bike, it took about 4 months to get my FTP where it was on the road bike. I’m assuming my fit is not optimal. I’m pretty sure if I went back to my road bike it would be higher than in aero.
There was about a 10% difference in 20 minute power intially.
Depends on which bike I use. If I use TT bike #1, my power is down about 10%, but the flipside is I’m way more aero (CdA in the 0.27 m^2 range without aero wheels or helmet on and ~0.22-0.23 geared up). TT bike #2 is more comfy, and my power is typically within 5% of road bike. But it also gives me about 0.02 m^2 more drag area. No real power difference on the road bike with position.
But you are on the right track - finding the balance. It’s not about putting out more watts. It’s all about maximizing speed, so sacrificing some power may very well be worth it.
Depends on which bike I use. If I use TT bike #1, my power is down about 10%, but the flipside is I’m way more aero (CdA in the 0.27 m^2 range without aero wheels or helmet on and ~0.22-0.23 geared up). TT bike #2 is more comfy, and my power is typically within 5% of road bike. But it also gives me about 0.02 m^2 more drag area.
Interesting ! What is the big difference in the setup of the two bikes ? Is it only spacers/drop or his seat height or others ?
Aero TT bike on flat terrain is ~30 watts less than on hood while climbing on road bike.
Thanks, this is roughly what I am seeing as well. Struggle doing my 2x20’ on the tri bike on trainer, but happily climb for an hour at close to FTP on the road bike.
The FTP I am using is probably too low for the road bike and too high for indoor on the tri bike.
that is sort of introducing two variables at once. climbing changes the inertial loads and that might explain some of the difference rather than just position.
Depends on which bike I use. If I use TT bike #1, my power is down about 10%, but the flipside is I’m way more aero (CdA in the 0.27 m^2 range without aero wheels or helmet on and ~0.22-0.23 geared up). TT bike #2 is more comfy, and my power is typically within 5% of road bike. But it also gives me about 0.02 m^2 more drag area.
Interesting ! What is the big difference in the setup of the two bikes ? Is it only spacers/drop or his seat height or others ?
Bike #1 - 56cm, 75 degree seat tube
Bike #2 - 53cm, 78 degree seat tube
Road bike(s) - 56cm, typically 73-75 degree seat tube angles
It’s mostly the seat tube angle and the longer top tube on the 56 compared to the 53, and I’m riding on the VERY tip of the saddle. Between the seat tube angle and longer top tube, I’m a long way from being UCI compliant. But beggars couldn’t be choosers. I got the frame before there were a lot of options on the market. Besides, to me it was somewhat of a collectible - a Hooker. Very aero frame for its day (and even today) but as stiff as a cooked noodle.
One thing about frame sizes - they all fit differently. Whenever I jump on my 56cm track bike I feel like I’m driving a clown car. Ultra-compact “cockpit” compared to a 56cm road bike.
Aero on TT bike is within 10 watts of aero (forearms on top of bars) of road bike.
Aero TT bike on flat terrain is ~30 watts less than on hood while climbing on road bike.
I’ve noticed that a lot this year while racing the Tri bike. In a 40k I can only hold say ~85% of FTP which I arrived at by riding for an actual hour on the hoods.
Is there a “solution” to this? i.e. do lots of intervals in aero orrrr… anything? Luckily 85% of FTP for 40k can be sub 58 minutes but it’s always better to be faster.
that is sort of introducing two variables at once. climbing changes the inertial loads and that might explain some of the difference rather than just position.
yep. That is why I did the test today of being in aero, coming out of aero. Same wattage, same bike, same cooling, same trainer.
Last week I was struggling to do my intervals on the trainer in aero. This weekend I was easily holding ftp climbing. I knew position was part of it, climbing was, cooling, motivation…so today I just wanted to see what going up and down in the aero position would do at it was about 3bpm and of course it felt harder.
It’s almost as if you need multiple FTPs. One for road bike climbing, one for TT bike on trainer, one for TT bike on road…
Is there a way to approximate cda saving per cm of drop ? I know it would be a very rough approximation.
I wouldn’t correlate any outdoor riding data to the trainer. As Jack said, that’s introduces a second, and very significant, variable.
Agree. I could have made the title “Is your FTP higher out of aero”. I think I’m trying to correlate position to power more than anything. I guess I’m trying to quantify it. I am seeing the lower I go the less watts I can generate, seems common, so now I need to find that right balance of low and powerful.
I will try of course riding steeper, seat higher, lower…
Yes, but let me first state this is what I believe works for ME (and a bunch of really good TTers I know), without any controlled medical studies to confirm that.
One of the staple workouts I do is called HOP, or hour of power. You build time and power, from 3x10 to 60 min, done at 70 to ~85% FTP, and 60-70rpm. They’re not that bad until you get to 2x30 min at higher power. The last 15 min of 1x60 is brutal. The muscle activation though hips/glutes is very different than any other workout and adapting to an aggressive aero position. Aside from that, it’s a great way to work on position discipline and concentration.
There was a long post on this that my inadequate search capabilities wouldn’t pull up. I think Joe Santos, Tom A and some others were all in it talking about position in case you want to look for it.
I actually get more on the TT bike than in the standard road drops position. The steep seat angle etc. really gets the power over the pedals. I can get there on the road bike but it isn’t very comfortable in the drops.
Yes, but let me first state this is what I believe works for ME, without any controlled medical studies proving it works.
One of the staple workouts I do is called HOP, or hour of power. You build time and power, from 3x10 to 60 min, done at 70 to ~85% FTP, and 60-70rpm. They’re not that bad until you get to 2x30 min at higher power. The last 15 min of 1x60 is brutal. The muscle activation though hips/glutes is very different than any other workout and adapting to an aggressive aero position. Aside from that, it’s a great way to work on position discipline and concentration.
There was a long post on this that my inadequate search capabilities wouldn’t pull up. I think Joe Santos, Tom A and some others were all in it talking about position in case you want to look for it.So what exactly are you trying to accomplish with this? Unless your event requires 60-70 rpm, what’s the point? And 70-85% of FTP? Sounds more like endurance. For me, the hang on for dear life workout is long tempo rides at 90% FTP. 2 hours straight at that level is pure hell, particularly the last 15-30 minutes. It takes time to extend the workout that long, but once you do you have some incredible fitness. It also takes the right terrain, or do it on a trainer. A variant of this is getting out of the saddle periodically and surge to 130%+ for 10-20 seconds and recover at 90%. Start with 3p minutes and add 10-15 minutes for each subsequent workout.
90% of FTP is not tempo riding. That’s the low end of threshold.Or the high end of tempo (and 75% to me is a good endurance pace)… Just look on the trainingpeaks site. Been treating this as tempo for the last 10 years, and I ain’t changin’ now.
The question was how to close the power loss gap between aero and road positions, not what workout is pure hell. The interval you posted has nothing to do with adaption to a position. And if I wanted to make the workout like you posted hard, I’d ride for 3 hours 75-80% and then ramp the 4th to 85%+.
But if you think HOP looks easy, go try it and report back.