I went on an endurance ride today, and I averaged 33.2 km/h and 230 W. I spent the majority of the time in the aero hoods position, alternating with the drops. There was no appreciable elevation gain (around 100 m, it is flat here ) and winds were calm.
It felt quite slow for the power I put in, and indeed, bestbikesplit and mywindsock tell me, I have the aerodynamic properties of a brick. The estimates I get for my CdA are 0.39ā0.40.
I am stumped why, though:
I wore tight-fitting clothing (2-piece).
I spent most of the time in the aero hoods position, alternating with the drops. I only went into the regular hoods position to drink or so.
I have an aero road bike (a 3T Strata) with 45 mm deep wheels.
I have Vittoria Corsas (not the Pros, but the previous-gen) in 28 mm. They used to be amongst the fastest tires. While I am sure there are faster tires out there, they are no Gatorskins.
I have had good bike fits, and I feel comfortable on the bike.
There are some gains to be had, e. g. I have a POC Octal, a non-aero helmet with lots of ventilation and 42 cm wide bars. Running narrower bars would cause fit issues as my knees reach bar/elbow height when riding in the aero hoods position. With the wider bars, they are next to one another.
Whatās going on here? Where can I improve? Thing is, I donāt see anything egregiously wrong with my setup.
Mywindsock usually estimate my CdA at around 0.28. Iām 177 at 70 kg.
It seems like you have the most obvious things under control.
Height is an important factor that is difficult to circumvent. Working on flexibility is one way to get around that problem. Recording yourself on the bike could reveal some possible issues. Regardless of your height try to be as narrow as possible on the bike; keep your legs close to the frame and elbows in.
Hope you find something of value in my post and good luck with your trouble shooting.
Yes, my road bike spends most of its life on the trainer.
No, Iām still running latex inner tubes.
I am very hairy ā¦ and feel I should shave my entire body then
Iām using a wax-based drip-on lube by UFO.
I weigh around 75 kg. I put in around 4.1 bar/60 psi into the tires. I used the usual tire pressure calculators for a baseline and then adjusted. We have lots of stretches with cobbles and bad roads around here, so I adjusted it downwards by 2ish psi.
Make sure you calibrate your PM every now and again, or when youāre doing a ride when you know you want to know more about your aero. Also, maybe try calibrating it against your turbo trainer?
Posting some pics will help; without knowing what you look like, its hard to give any individual advice/suggestions.
Howeverā¦ if you ride with others, try seeing what happens on the downhills - can you freewheel past others? Do you carry speed well? Or are you working hard to hold the group on the downs?
On the turbo, set up a mirror so you can see yourself head-on, and look at whatās happening. Big things to watch out for are; head popping up well above your body, elbows sticking out, knees sticking out, torso too upright. Hope this helps.
I typically manually zero my power meter before every (trainer) ride. I donāt think I did last weekend, though.
I have done that, and the two disagree. When I got my Elite Suito new, the two were very close. I didnāt use @dcrainmaker analysis tool, but they were close. (I used my head unit to display the Suitoās numbers and compared them live to my power meter.)
After two years or so I tried again out of curiosity and there was a significant disparity in both, slope and offset. I tried a spin down a several times, but it didnāt help. The Suito read a lot lower than my Quarq.
On the other hand, I used select Strava segments to validate whether I had gotten faster and at that time, the answer was a clear yes. I even eeked into the 10th spot of a very popular lokal segment, a 6ā7ish-minute climb, only to be overtaken the next day by someone else.
But a hot power meter is definitely one of the potential contributing factors I am looking at. Like I wrote, I donāt claim to be the most aero person in the world, but I should be in the ballpark of a moderately aero person. The discrepancy is significant, though: the Quarq would have to read 30 W over at 230 W displayed to bring me to a CdA of around 0.35.
Iāll have to figure out a way to do that, but thatās definitely something Iām looking at.
After moving I havenāt found a new group yet. Basically, the group rides here are on Sundays, which also happens to be my wifeās gym day.
In Japan I was one of the fastest in my team. On the flats, I was probably one of the strongest (as I am heavier and have had a very high comparative absolute FTP) while on climbs I was still good. Some were better descenders.
On top of all the good inputs above, I would still move to a narrower handlebar (UCI legal or not) This will influence the overall fit of the bike. In my case, I needed to have a longer reach (stem in my case).
I can also only recommend aerosocks and aerohelmet, especially if you donāt have elevation where you ride.
The other option is get less aero but into a position you can hold higher power longerā¦
One way to get faster other than just increasing your fitness. I think Aero gains are the tip of the pyramid once youāve already mastered, training, fueling, recovery, and preparing for the targeted ride. That said - Its fun to buy new stuff, get deeper wheels if youāre on 45s and on mostly flats. Iād also continue to push the narrower bars. I have to believe you can get used to or make them work.
Think your PM might be off. Getting faster on Strava segments could also just be due to familiarity, weather conditions, faster bike setup etc.
Did it feel like 230 W, compared to the trainer?
Was this an āevenā power and speed effort, ie without much variation in the power? Not many hills, corners, crossings etc - while those might not matter much for avarage power, they could bring your speed down.
I use power match, i. e. the source of truth is my Quarq in both cases. When I noticed the discrepancy, I decided to stick to my Quarq, not because it reads higher, but for consistencyās sake.
Yes, the effort was quite evenly paced. My variability index was 1.02 = 232 W/236 W over 1:59:46 hours. I think thatās pretty good. There were some cases where I had to put in more power and/or slow down. (E. g. there were some cobbled sections.)
That doesnāt mean much. In a decent downhill the fastest rider is merely the one with the highest weight to CdA ratio. Iām on the taller and heavier side and get gapped off the back on the climb and quickly catch back on in the descent. Is not because of superior or necessarily even similar aero.
Comparing long rides like this is not very accurate. Thereās lots of potential factors at play that arenāt easy to account for:
Changes in wind speed and relative direction and being sheltered or not by buildings/foliage
Changes in road surface roughness
Slowing down and speeding up for traffic, intersections, etc
Hills (sounds like not a factor here, but even slight grades matter if itās not an out and back)
Your position on the bike is likely changing a lot over the ride. Even if you keep your hands in the same position, your back angle, elbow angles, elbow flare, head position, etc are probably changing, especially over 2 hours
Your power meter calibration can drift over a longer ride due to temperature changes (some power meters automatically compensate, some donāt)
You mentioned cobbles. Even though you kept power pretty steady, they would have slowed you down a lot, messing up the CdA estimate. Your roads might be rougher and slower in general. Rolling resistance can be a significant power waste even if you have low rolling resistance tires.
Instead you should do a segment of really smooth fiat road on a near windless day. Ride it in both directions (to really zero out any elevation and wind influence). Take the average off speed and power for both directions and plug that data into BBS.
And itās pointless to estimate CdA if your power meter is suspect. See if you can find another power meter or trainer to test it against, so you know if itās your trainer or PM thatās borked.
Thatās a very good suggestion, something I hadnāt considered even though it felt obvious once you have mentioned it. Thanks
Yup, plenty of that. Keeping my power steady is not easy. If you look at my power data, it seems I am doing very badly and cannot stick to Z2. But since I am aiming at the top of Z2, slightly variations in wind or undulations can put me slightly in Z3.
This is indeed a huge factor. Some roads are alright. Others are horrific. Then there are stretches of cobbles, which slow you down a lot. They are not super long (i. e. the very long stretches I avoid after puncturing really badly once), but they meaningfully slow me down.
I have to ride through villages, which are like pearls on a string.
) and winds were calm.
