Position is everything. You want to strike a balance between aerodynamics, handling, and comfort. Some parts of your loop might be faster if you're in the drops, while others will be faster ridden with an aero-hood position (see the photo I posted above showing this). This will take time and will not feel natural at first or for long durations.

Equipment is another avenue to explore and is a good easy complement. Latex tubes are an easy way to gain watts and yes 5000s will likely be faster than what you have without increasing your puncture risk. I only keep butyl for spares in case I flat out on the road.

---

My YouTubes

I would kill for 275 watts - I have to deal with the fact that my 67 year old legs can only do so much, like maybe 175 FTP on a good day. So I got a decent bike (Trek SC) paid for a good fit and started improving my position as much as possible. I don't know what my cda is but I believe it's around .23 which gets me decent racing results. I'm not sure I would put that effort into a road bike scenario but all the things mentioned upthread will help your situation:

Latex tubes, not butyl btw.

---

"They know f_ck-all over at Slowtwitch"
- Lionel Sanders

cda is coefficient of drag * area of your body exposed to the air in front of you - basically it's the number you calculate your aerodynamic drag from. The lower the number, the less aerodynamic drag.

You can improve cda by reducing the area exposed to the wind in front of you. Perhaps a picture of your typical position on your bike in the clothing you normally wear would help us find ways to improve.

Yes, riding in the drops will help but that may not be comfortable all of the time. Tires and tubes can help too (and I wouldn't ignore them) but aero drag from our bodies account for most of the drag on a bike.

At 275 watts you appear to be putting out enough power to ride well over 20mph for extended periods. You either have an issue measuring power, have a lot of drag or both. I'm trying to help determine what your needs are to go faster.

Butyl rubber tubes are slow.

You want latex.

I will try and get a picture next week and post it. Thanks for all the advice.

We have a Peloton which I only use occasionally, but my power numbers on that bike are very similar to what I see on my road bike and tri bike. I realize the Peloton only estimates power, but I now have three different devices showing similar power numbers. Even if the PM off by 10-15 watts, I am pretty sure I can put out 260+ watts for a long time on any bike. Now I just need to improve my cda.

cdA is your coefficient of drag multiplied by your frontal area exposed to the wind.

For example, a cylinder ( round tubes ) are not aerodynamically efficient compared to an aerodynamic tube in the approximate shape of a tear droplet with a blunt leading edge, so the cylinder would have a higher coefficient of drag. Even if the frontal surface area is the same, the aero tubing is faster.

As the frontal surface area increases, eg the cylinder gets larger, so does cdA ( the area portion )

So the worse the shape, the more drag, and the larger the shape the more drag.

To improve these things, you want to do what you can to get slippery in the wind ( eg a good aero helmet, tight fitting clothing, shoes with less protruding buckles, maybe covers, shave legs etc. ) as well as try to lower your frontal surface area ( getting lower )

You have to find the right balance since you still want to be comfortable, and be able to generate power, not just fold yourself in half at the hip and hope for the best, so generally a good bike fit is a good idea. Some of the people on here can provide criticisms to a bike fit to at least get started.

Tires are a LITTLE different. Tire/rim SHAPE has to do with your aerodynamics, for example, you want the widest part of your rim to be 105% of the measured width of your tire in order to maximize aerodynamic efficiency of your tire/rim system.

However tire type such as the GP5000 generally comes down to rolling resistance ( essentially the energy loss in the deformation of the tire as it rolls ) GP5000 with latex tubes is a pretty fast setup, I run it on my road and tri bikes. There are a couple faster tires, but they tend to be more thin and fragile.

Power to overcome rolling resistance increases linearly with speed, whereas air resistance increases as a squared relationship with speed. ( eg, doubling your speed = 4 times the air resistance )

However power to overcome aerodynamic drag has a cubed relationship with speed. So to double your speed, you are producing 8 times the drag.

To increase speed 10% ( 1.10^3 ) you are looking at a 33% increase in the portion of power to overcome air resistance. Generally speaking 70-90% of your power output is to overcome aerodynamic drag ( faster you go the higher % )

This all shows why aerodynamics are so important in cycling.

BTW, thanks for the help on the Felt IA. The bike works well for me.

To put some of the power vs speed numbers into perspective, couple days ago I did a ride, and I attacked a couple of hills during it, but kept most of it fairly easy.

I averaged 188 watts for the ride, and averaged 20 mph.

I tend to have an aggressively aero position on my road bike, but wasn't holding to the extremes of the position the entire ride.

Bike Calculator would estimate close to 21 mph when I plug in my weight, elevation etc. at 188 watts.

So either you have a LOT of low hanging aero/efficiency fruit, or as it's been said above, your power meter is a bit off.

No problem, glad it worked out well for you!!

I wanted to report back with an update. I rode the same loop today, windier day today, but used my tri bike. I have a 2009 Felt B16, stock wheels, Victoria 23mm tires with Butyl tubes. I ended up averaging 268 watts and 23.1 mph for 10 miles. So about 2.5 mph faster than my road bike on less watts. I have the P1 pedals on the tri bike, left side only.

I think if I can manage to lose 10 lbs I should see an increase in speed on less watts. But the ride today was encouraging to know I can hold over 23 mph for a good amount of time on a very windy day,

You're riding solo, right?

If you are riding alone, on a road bike, those numbers aren't unreasonable. Sure, some might be able to go a little faster on the same watts, but YMMV.

Now, if you really want to go faster, join a group ride or hop on a TT bike.

e.g. (on a TT bike) I'm about the same weight as you and an average of 280W over an hour will put me around ~26 mph (56:30 40k TT).
e.g. (on a road bike) In a local crit race, I'll average 260w over an hour and finish with an average speed upwards of 27.5mph (sadly, that's only good enough to keep me in the midfield pack).

So don't worry too much about your speed on a solo ride. Get in a fast group ride and see what you can do!

See if you can test drive another powermeter and see what figures you get.

Validate a route on bestbikesplit.com?

What are you wearing? I ask because if it's a loose top, then that is likely to make a huge difference. As an indication, and not trumpet blowing, I'm a fairly strong (but not amazing) rider and in my usual saturday bunch ride one of two that on the flat get yelled at for accidentally gradually riding away with people not able to hold the wheel. Typically I'll be at about 260w on my non aero rodie with non aero wheels and non aero helmet, 90kg 6ft 4" tall about 35kph on the front. That's also 180w in the pack. But one week I was being a wuss in drizzle, couldn't find my normal rain jacket and so grabbed an old one that was a bit baggy. I was pulling 350w+ in second wheel and front rider was pulling away from me (ie I was at 33kph). Nearly died on that ride.

For reference then on my TT bike for last half ironman then I did 265w for 90km / 2h12m argon E-114 with s80 wheels aero helmet and desoto skinsuit.

For added reference, I had a race a couple years ago with similar stats, I did 90 km at 24.5 ish mph, so 90 km in 2:16 and change, at an average of 254 watts, and my position certainly was not as optimized then as it is now, but was running a tight one piece tri suit, aero helmet, hed jet 9 front, hed jet disc rear.

Last week I did a 44.5 km ride on the TT bike with my improved position, just testing a few things out, and it even included 2 hard 2 minute efforts ( which brings the average power up more than it brings the average speed up due to the cubic increase in power needed to overcome aerodynamic drag as velocity increases )

I averaged 37.6 km/h or 23.4 mph at 209 average watts. ( This would net a 2:23 split for 90 km in a half iron )

Compare this to a recent ride on my road bike, almost the identical ride, with the same average speed ( 37.6 km/h ) but took me 255 watts to produce the same speed here.

Aerodynamics, position etc. are MASSIVE and will do a LOT more for you than losing 10 pounds will. ( In fact, I tend to time trial better slightly heavier as I produce more power and it's all about watts / cdA in time trialing, not watts/kg, the only real benefit of losing weight is a SLIGHT reduction in frontal area and perhaps a couple seconds saved on a climb )

Load the ride into Bestbikesplit.com, that will use all of the information to calculate roughly what your cda was. If you share your cda, then it should be easy to determine if the ride was slow

Good Butyle tubes are only 1-2w slower the Latex (I use Latex as I prefer the feel)
I am guessing you have Specialized Turbo Cotton tires which are standard fit on Tarmac S-Works, if so, they are great tires

The biggest factor is aerodynamic drag, Drive train loss is around 3-4% and rolling resistance loss is 9-11%, therefore drag is around 85%. The rider represents around 65%-75% of drag, wheels and tires around 17-23% and bike frame 8%-12% (obviously these change a little as you optimise)

I don't have an S Works, just a basic Tarmac. I just have the tires that came with the bike, can't recall the name.

This one?

https://www.specialized.com/us/en/tarmac-sl6/p/175300?color=293448-175300&searchText=90621-7044

---

My YouTubes

Yes. Love that bike.

Not sure anyone has tested those tires (turbo pros), but i'm going to go out on a limb and suggest they're on the slower side.

These would make for a marked improvement in regards to feel and speed: https://www.specialized.com/...earchText=00015-1503

Grab some latex tubes to go with them.

---

My YouTubes

I do have a new set of Conti GP5000, 26mm. Would those also be a decent upgrade, along with latex tubes?

For sure! Nice choice.

---

My YouTubes

26mm?

GP5000's + latex isn't a decent upgrade, it's a great upgrade. You sure you have 26mm? I didn't think GP5000's came in that size.

In case you didn't know, if you carry a spare tube for your rides, bring a butyl tube if you use CO2 to inflate. Latex will not hold CO2 for very long.

Have you scheduled/received a bike fit? I'm not an expert, but I also bought a proper roadie recently (after years of only riding TT bikes) and got a (roadie) bike fit and...

Holy shit, a real personalized and properly fitted road bike is so effortless (relative to my TT bike & position) to ride. I don't have much data to back up at this point, but I have noticed that riding my new roadie, I put in less effort to achieve the same (if not higher) power and speed as my TT. Climbs are easier too. Not to mention improvement in stability and handling; suddenly I find myself bombing down hills I used to be afraid of and cornering like it's MotoGP.

These new insights and experiences from a (road) bike fitting has me thinking that my TT bike position is way fucking off, and needs complete overhaul (even though comfortable); and, as we all know the biggest limiting factor on a bike is the rider, a whole greater appreciation of what a real bike fit can achieve. Far far more than what equipment and new gear can provide.

just sharing!