I’m using a road bike with clip-on aero bars and have changed the bike to more of a TT setup to allow for the aero position. Seat foreward and up, 165mm cranks instead of 172,5 and a longer stem.
When riding in the TT position however, I feel my quads are getting significantly more work versus riding at the same power but more upright.
Can anyone explain me why this is the case? Is it inherent for a TT position, or maybe a lack of flexibility, or wrong bike fit?
Try a test. Pedal along in aero until you feel the loading build. The keep same power and cadence while you move up to the hoods. See if the opened hip angle changes your loading,
I try to mix in aero bits in my TR workouts, so I have a pretty good feel on the difference between upright and aero for a given power. Upright I almost never have any issues feeling the quads, not even on this week’s Carpathian Peak +2. However when in aero the quad dominant feeling already starts around sweetspot.
Then that’s a sign the drop may be more than your body is ready for now. Might try to raise it a bit (to max aero height?) and work back down over time in smaller steps.
It is perfectly normal that your power output in your aero position is different. There are many factors, some might simply be that your muscles haven’t had enough time yet to reach the level of efficiency you have in your road bike position.
For me it appears to be a mix of general discomfort contributing to my RPE, less room for breathing and restricted blood flow through the femoral artery at 11 - 01 o’clock.
Spending more time in aero definitely helps, but it requires commitment. I’ve had best results when I dropped my FTP to a “aero-FTP” and completed everything up to FTP in my aero position. This approach limits your overall FTP growth for a while, but it helps getting the body efficient in your TT position.
Also, bike fit clearly pals a role here and if you aren’t sure about your position you could consider finding a reputable fitter in your area.
Thanks for the help guys!
I feel my aero position is pretty okay as far as comfort and power goes. For reference, I have no problem sustaining the position for an hour or even more outside. Power in aero is definately a bit lower in aero vs upright, but not too much I think. I’m regularly able to do a sweetspot or FTP interval that is based on upright ftp in the aero position, allthough RPE feels a lot higher due to the restricted breathing and more fatique in the quads. HR also tends to be a bit higher.
Could it maybe also be caused by a lack of glute/hamstring activity? Definately feels harder to activate them because of the more closed hip angle.
I have a similar problem and maybe a answer for your question…
Many times, during past three years, I got into the state of having spasms/cramps in my quads for a days (maybe even a week). The last spasmy-crampy period was like a week ago. The common thing among all periods is using my TT bike too much. For example, for the last two seasons I almost exclusively rode the TT bike, with only a few races on road bike. I am perfectly comfortable doing 4h workouts, climbing, descending and holding aero position whole time, but I have a feeling that it causes the overuse of my quads… And I have a Retul fit, so my position should be okay, but I got them even before my fit so… 
Now I am training to find a solution, maybe it is caused by overuse or lack of glute/hamstring activity (opposite muscles, connected muscles, etc. ). But I am definitely sticking to my road bike now.
Can you get someone to take a photo and post it? Riding in the TT pos is a learned position you use slightly different muscles and pedal technique. Where is the saddle position over your BB or forward of the BB? Once you have a good pos then your body will adjust to it. being able to put out power in the TT pos is something that comes from training in that position.
how many times can you say position in one response ;0
Thanks.
Don’t have any photos atm, will see what I can come up with.
The tip of my saddle is currently as far foreward as I can get it and is 6-7cm behind the BB. Being a road bike it’s unfortunately not possible to get it any more foreward.
Tip of saddle to arm pad drop is around 8cm, so not that agressive imo.
Is your seat post a set back post? You might want to look into that. Power transfer is ideally over the BB 6-8cms behind is what could be causing your quads to over work.
What size crank are you running?
Your saddle height compared to your road bike height might need adjusting as well. Because of the opening of your hip angles.
Using the standard seatpost that came with my bike, a Giant TCR Advanced.
Crank size 165, because the standard 172.5 was restricting breathing too much.
Compared to my road bike position, I shifted my saddle foreward and up to account for the change relative to BB and crank length.
Getting a new saddle (Bontrager Hilo Comp) today, so maybe I that has a different rail position allowing it to closer to my BB. Hope it’s at least more comfy than the saddle I’m using now (Pro Stealth).
Hey mate - yes the TCR Advanced because of the geometry - you would have the seat rails on its limit , hopefully the new seat has longer rails.
Fitted the new saddle today (Bontrager Hilo Comp) and I can’t get it any more foreward that my old saddle.
However, due to it being a split nose saddle I’m able sit more foreward, so this is definately a win!
Tested it in TT position on the trainer today during a recovery ride. I find comfort get worse in TT the lower the power output is due to extra pressure on sit area. But this time I was able to stay in position for 30 minutes no problem. Another win! Will have to wait and see how my quads hold up when I start training again next week.
I got down to making some photo’s of my TT positionand I’ve put em up in the Bike Fitting Mega Thread:
Also did a close to FTP type effort in TT position today and I could definately feel an improvement. Less quad dominance and I could feel my glutes/hams do some work.