Hermes

I thought it was a great selfie that took the classic garage door pic to the next level. The angle showing BTS and the bike against the sky is very cool.

And I thought of the 50s Superman TV series.

wktmeow

What about "Trinity," like from The Matrix

kensuf

Clearly the bike.

bOsscO

I'll post this in the gadgets threads too. New tool to measure how aero you are; https://giblitech.com/

burnthesheep

My junior cassette came in. R8000 14-28. This will be an interesting little TT bike project to see how this works out.

burnthesheep

I'll go ahead and say it.......the wheel speed sensor vs GPS thing really bothers me. I get that folks don't want an extra sensor, but in all of this bike CdA stuff......having an accurate instantaneous speed is critical.

I still think to do this "well" and really sniff out stuff, you need to do the post-ride work. Versus the novelty of in-ride readings.

I think the folks on a budget who really "get it" are those using some kind of Chinese air speed sensor that then overlay that data into the VE worksheet and still use a speed sensor and an SRM or Quarq.

I'm still in the camp that this costs enough money versus how much work I'm going to have to do myself that I'd pay the $1000 to go to the tunnel for 90min.

Hermes

My wife and I have about 9 hours of testing at Velo Sports Center using ERO software and electronics to generate instantaneous CdA as we ride around the indoor track. Plus ERO does an in studio Retul set up where the position is compared to their data base of international racers and UCI pros i.e. what is your hip angle compared to X. Then one goes onto the track and tests different positions and using highly accurate equipment.

And ERO already knows what works and is fast so it is a matter of confirmation of the position and equipment on the rider.

Finally, one learns a lot from the experience about aero testing, position and equipment from ERO. Nothing beats an in person coach / tester with vast database and knowledge.

One thing about the indoor track testing and track testing in general is that it is head on. One is not tested at various yaw angles which is where the tunnel may be better. One of the BF racers, who has done both ERO and the tunnel prefers the indoor track.

One wants accurate speed and power reading and GPS will not work in the indoor track.

However, an on bike aero gizmo may offer some benefit just like workout apps offer some benefit to cyclists for training. And it may turn out to be great.

burnthesheep

Not sure why I hadn't setup the synchro shift on this thing yet. Figured out it has the bluetooth connection and can use e-tube. That's cool. I hear just to never let it update the firmware, haha. I didn't let it. But that synchro shift is freaking cool, especially for a TT bike given that when you go big ring to small you're likely taking your hands off the extensions and going to the base bar at the same time as you're slowing up a hill.

kensuf

You don't need accurate speed. I think accurate power and HR is very very very useful for pacing yourself, but speed is isn't really helpful.

Hermes

I think BTS is referring to CdA calculation. Accurate speed is required/essential.

With respect to training and racing, power is ones currency to buy speed. Racing is all about speed. Hence more power is good but reducing the cost of speed by reducing CdA and rolling resistance as well as drive train losses is important as well meaning one can purchase more speed with less power.

kensuf

Oh yeah, and for windtunnel testing too.

But on race day, eff it, so many variables come into play on "speed" and the only thing that matters is being faster than everyone else and pacing yourself so you don't blow up too soon, but also do the best you possibly can.

burnthesheep

Accurate speed is to calculate CdA using speed, power, estimated crr, airspeed.

GPS speed figures for that calc don’t work great. Wheel speed is better.

Google “Chung Method virtual elevation calculation”.

kensuf

Chung used to contribute here a few times. I'm familiar with him.

While drag DOES matter during a race, accurate speed measurements don't. Simply being faster than everyone else is what matters.

burnthesheep

They were right above, I only use that for doing testing. Races in TT speed isn't even a field on my GPS usually. If it's hilly enough I'll add it so when I slow going uphill I'll come out of aero once there's that switchover between where making more power sat up versus less power in aero matters on a hill. If it is flat.......total distance, HR, power. That's it. Even then power and HR is a glance once in a while to stay honest. No real watching it, hammer.

But, I'm going to start adding in a weekly TT now. Found a guy putting one on in town. Only concern is he's too ambitious on his route. It crosses two stop LIGHTS. Not signs, lights. Just to gain 2mi distance. I'll skip that. I want to live.

Doing my 3x8's yesterday my speed with a flappy retro Lemond jersey on and nice road helmet was pretty good.

burnthesheep

Found a road, posted up on team site. Once we get a touch more early AM daylight, going to do a 50mi try for sub-2. Old Oxford Rd. See if anyone wants to tag along.

Last week with u-turns and non-ideal roads and kit I was pretty close for 30 miles. With just the one u-turn and my nice kit, I think I should be able to do it.

Is it reasonable for a Cat 4 or 3 to suck your wheel on a road bike at that speed? 25 isn't that fast. I'm smallish, but it couldn't be THAT bad.

Hermes

A lot has to do with the wind and your speed control. My wife and I do TTT all the time and she can ride at 25 mph on her TT bike. And she has a tiny CdA for her power. While her power is reasonably constant her speed may vary. My road bike power fluctuates a lot and I have to react to fast changes in wind force.

The other thing that happens is I lower her CdA when I am behind her. We tested this at ERO at the indoor track. ERO was surprised by the difference. So when I am 6 inches off her wheel, her speed goes up and my power goes up as I get closer. It is sort of crazy.

The bottom line to answer your question is yes it is reasonable for a Cat 4 or 3 to draft you at 25 mph but it is going to be more about ambient conditions and his/her execution and concentration capability than pure power. As well as your ability to hold constant power / speed and ride in a straight line. But as always, if someone has enough power and strength to overcome all challenges then execution is rendered mute. However, that rarely happens.

burnthesheep

It is a teammate(s) that we practice rotating together.

Hmm, the boost in speed from that CdA change has me thinking though if it becomes a fair challenge. As right now, it is one of those "at the realm of ability" challenges for me for that distance. With a boost, it may not be as fair.

But my power for TT riding has smoothed a LOT the last year or so, as I've been riding it a lot and focusing during the rides after seeing the power and results in my data afterwards.

We'll see. I had forgotten the aero boost to the front person by having a follower.

burnthesheep

The practice TT, at bit less than all out race. Good yard stick for race day. I can beat that.

-25mi: 56:22

burnthesheep

FWIW, USAC road nationals for TT explicitly calls out triathlon hydration as a no-no. A couple guys this past weekend got called out by the USAC official, then allowed to ride. They were also calling out the larger "storage" boxes that serve as aero also and if it wasn't bolted, asked to remove it by slipping it off and chucking it. Also saw you can't ride a triathlon superbike, must be diamond frame style.

So......a little less "loosey goosey" than I had heard in the past.

I'm cool with that. It's a TT, not a triathlon. It was totally the triathlon bums getting called out also.

ntnyln

I've seen a little bit of the Tri stuff around here in the TT only events, not the bikes but just the hydration and aero tidbits, but those guys usually aren't at the front end of standings. It does get my OCD going a bit though.

burnthesheep

Ok, this is definitely a solid hobby of mine. I'll never be some super powerful stud but would like to continue to grow and learn.

I cannot afford tunnel time. I'm a cat 4/5 nobody that just happens to be kind of quick. But, the aero sensors have apparently gotten good enough now that legit folks are using them in the field.

I'm looking at the Notio for $600. I've spent more on a single wheel before. I also figure I might be able to post up on the local FB group and loan it out time to time for some pocket money.

Any strong opinions in the group on this at the moment? The industry folks (ones not selling sensors but other aero equipment) from Aerocoach and others over on Slowtwitch are coming around to thinking it's a viable solution for folks still smart enough to use one.

I'm just tired of all the Excel work with virtual elevation. I'm not into "real time" visual of CdA but simply faster post-work analysis. I feel I can do/try more things if I owned the sensor.

I "might" be able to squeeze 10w more on power by next year. But adding a 10w aero gain from somewhere would be awesome also.

topflightpro

You know, you probably could rent it out and end up making your money back on it. If you charged like $20 a day for use. I think you could probably find enough people interested to rent it from you.

And if you kept the price kind of low - like $10-$20 or so - I think you could attract more people who are just interested in knowing more about their aero profile and are willing to put a few bucks to check it out. If you were to charge a lot, you'd probably only get the real hardcore people.

burnthesheep

Was my exact thought. I also thought I could make it a training ride with somebody else while I show them how to do their laps and such then shoot them their data. To keep it easier I'd probably setup a dummy Strava account for just that Garmin gps paired to it that's private then mail out the files.

Nothing "expert" at all. Simply loaning it for some small jingle and showing up for the hour or two to show them what to do and I can ride my own training while they do it. Then shoot over the files after.

I do think perhaps the app has a keyed pairing to the device where there's a "coach" level account that costs more. So I'd have to probably export the data and mail it out. Not a huge deal if it pays for itself.

I think I'll do it. I just sold an R8000 crankset I didn't need whatsoever yesterday (silly long arms). So there's like $150 of the $600.

Edit: bought......it works with just the phone app so will start with that. I'm trawling for a used Garmin 130 in case somebody borrowing it would want to use it "live".

Hermes

Kudos to early adopters. burnthesheep go for it.

When Velo Sports Center announced that they had planned aero testing services at Carson, I immediately asked to be a beta tester. Their system featured embedded sensors in the track and an electronic bridge on the bike that transmitted speed and power information to the sensors. The sensors were connected to a computer system that showed power, speed and CdA calculated instantaneously as one rode around the track. And they had an Rho meter to measure air density.

The software developed by ERO was quite sophisticated in that it had to take into account the turns in the track and the center of gravity changes as the bike leans to correct the received raw data.

This system was head on measurement and required a clean track with no air movement. No yaw measurement was available. One had to “rent” the indoor track for 3 hours to do testing.

One of the keys to aero testing is to know what to test for (operator expertise), have alternative equipment and clothing to test and have enough fitness to ride for 3 hours of testing. When I did my first testing, I did 200 laps and was pretty gassed at the end. We always did a couple of fast laps in a 10 lap set. Why? Because riders change position during high power. Most riders CdA goes up under high power and mine went down a little.

If you go to ERO today, they have helmets, clothes, saddles and stems plus a massive database of international, UCI pro team riders and etc that they draw from and of course knowledge of UCI fit rules if that is applicable.

So to start an aero business from scratch, there is a lot of stuff to make it truly valuable to a racer who says I want to improve my CdA and ride faster.

ntnyln

I've thought about this too. What I learned from my short exploration is what Hermes pointed out with operator expertise and that there are still too many variables to be managed for true consumer use right now. That said, I also agree with Hermes said and you should go for it and let us know how it goes.