This question is specific to Timetrials, and it isn’t about needing or not needing to drink, but what is or could be more aero.
I have the new Trek Speed Concept TT, and I tested their large water bottle on my TT bike (their bottle only attaches to the SLR tri frameset, so I made a shim to fit it to my TT bike). Over a 3.5 min segment there was no difference in the 1st run out, and then back it was slightly faster without the bottle.
1 Out Aero Trek Water Bottle
24.1mph / 3:30min
1 Out No Water Bottle
24.1mph / 3:30min
2 Back Aero Trek Water Bottle
24.2mph / 3:29min
2 Back No Water Bottle
24.4mph / 3:28min
I did similar testing with the Kit Crono CX Carbon water bottle (older dimpled version), and found it was slightly faster to run my set up with the bottle, with a difference of +0.2mph. I’ve seen the pros running the Kit Crono aero water bottle, and I’m assuming this was tested to be faster, and I’m wondering if this is indeed the case, but with my test results of the larger Trek bottle, and AeroCoach testing the Giant AeroWater bottle as 1.1 watt slower, I am doubting my findings with the Kit Crono. Thoughts, has anybody done similar testing and what have you found?
Note: these were done an out and back on the same day, within minutes of each run, same wind conditions, same power.
Yeah, I mentioned that in the post (“AeroCoach testing the Giant AeroWater bottle as 1.1 watt slower”), the issue is, at least according to AeroCoach, is that bottle is specific to the Giant frame, and may have not been the best example to use.
IDK if you can really say based on these 4 runs. You’ve got a :01 difference on the back back section with no bottle. If you only did the 4 runs the noise is loud and the data is like someone whispering to you across a 6 lane highway
Now if you do several more runs on several days in different wind conditions and find a trend that would be more believable. Right now you’ve got a shoulder shrug.
Hmmm, thanks for the input, I guess Ill have to test a few more times. It looks like aero bottles offer no benefit or disadvantage…but it needs more data like you said.
I love this “geeky†kind of post
Since we amateur work with limited equipment. I also want to know more about the aero bottle and most effective position. Also you can test the aero bottle flat behind the saddle (joe skipper like).
Do you have anymore that points beside speed you can add to your testing protocol? Power maybe? Cda with a aero sensor would be ideal.
I’m honestly not interested in the bottle behind the saddle, since I my focus is TTs, and there are a few TT in the season over 40min where I may need water.
I didn’t go off of speed, I went off power, which was the same for each run (235w). I find it easier to maintain the same ave power vs ave speed.
I believe AeroCoach found a standard round bottle on the seattube was faster than on the downtube, but this is for a road bike, and this can differ based on the road bike. The SpeedConcept was designed to have the water bottle on the downtube, and aero bottles are also designed to work on the downtube, and they have the same result as a bottle behind the saddle.
The time differences are small enough for bottles that one mistake or issue replacing the bottle back behind the seat would very quickly negate the benefits.
Same with aero bottles on the down tube, they are often way more of a faff, although there is a company in the UK I am going to test out who use a bottle cage with a tapered prong, for supposedly easier replacement.
The time differences are small enough for bottles that one mistake or issue replacing the bottle back behind the seat would very quickly negate the benefits.
Same with aero bottles on the down tube, they are often way more of a faff, although there is a company in the UK I am going to test out who use a bottle cage with a tapered prong, for supposedly easier replacement.
this…
downtube or between the arms is the way to go imo (it’s not the just the bottle, people need to account for reach for the bottle too)
Aerocoach has the data for this. No bottle for TT if you can handle not drinking.
Train up to the distance/climate to not drink. Outside of straight up being outside of the rules for bottles in TT’s, you’ll be slower to use one. To quote what I heard in the start line at the regional USAC TT from the official to a guy “this is a TT, not a triathlon, no BTA or BTS, you need to go take that off”. Generally they let people ride framesets with hydration in the frame, but you have to remove the straw and not drink from it.
Bottles in a TT go on the downtube or seat tube bosses. Nowhere else. Folks have tucked camelbaks under the suits before, but pros at least I thought cannot do that anymore. It would be sneaky for a non-pro amateur event, and is innovative, but personally I feel like it’s one of those where you’re thumbing your nose at the ruleset a bit half hoping you don’t get caught. Meaning, I wouldn’t do it. It’s a freaking amateur TT, it isn’t going to make your life to use a camelbak or not.
Did you go off average power or normalized power? Both of them have benefits and drawbacks. An extreme example to illustrate, you could average 235w by doing 1min @470/ 1min @0w. Ditto for normalized but with a smaller swing. Since your drag doesn’t increase linearly and your power does this is not going to produce a reliable result. Of course you didn’t do the test in such a silly manner, but even swings of ~10w on such a short test can make a difference.
Were these done from a standing start or rolling start? Was the speed the same at the start of each? Standing starts are a great place to gain/lose a second or two, and to fully mess with average power over a short period.
What about the end? Did you finish at the exact same spot? Again, a 1 second difference is easily the result of clicking the lap button a few meters either direction.
Chung analysis lays out a solid testing methodology, as well as free software available through Golden Cheetah to analyze. Again this is only as good as the data you get (GIGO).
Side note - the shim to attach the bottle to the frame, is it flush and inline with everything? I can imagine both a well made integrated shim and also a piece with gaps and overhangs.
My question wasn’t about needing hydration, but whether an aero bottle was faster than not having one. Look at the pros doing TTs, they run aero water bottles, but the data seems to show slower or 0 gains. Aero bottles in a TT are legal on the downtube or seattube, but you need to have water in it.
Not normalized power, but if you are wondering, both were the same since this was done on our local canal area that is flat, with no turns, and no cars, in fact, the time that I tested, there were no other people or riders on the canal. It doesn’t get much traffic.
Standing / trackstand start from a start line to a finish line. I even went back to make sure start and stop finished exactly in the same places based on GPS. Speed and watts were pretty dead one for all runs.
The shim is inside of the bottle cage, it’s used to clamp the cage against the frame from inside of the cage, not the outside.
Aerocoach has the data for this. No bottle for TT if you can handle not drinking.
Train up to the distance/climate to not drink. Outside of straight up being outside of the rules for bottles in TT’s, you’ll be slower to use one. To quote what I heard in the start line at the regional USAC TT from the official to a guy “this is a TT, not a triathlon, no BTA or BTS, you need to go take that off”. Generally they let people ride framesets with hydration in the frame, but you have to remove the straw and not drink from it.
Bottles in a TT go on the downtube or seat tube bosses. Nowhere else. Folks have tucked camelbaks under the suits before, but pros at least I thought cannot do that anymore. It would be sneaky for a non-pro amateur event, and is innovative, but personally I feel like it’s one of those where you’re thumbing your nose at the ruleset a bit half hoping you don’t get caught. Meaning, I wouldn’t do it. It’s a freaking amateur TT, it isn’t going to make your life to use a camelbak or not.
Curious how much if any of the first post did you read?
I barely skimmed it and the gist I got was ‘I read the aerocoach data but my very small real world test is showing opposite results, is this possible? Not interested in actual fluid intake’
And yet here you are telling OP to go to a resource he mentioned already having read and explaining something that he never asked about.
Aerocoach has the data for this. No bottle for TT if you can handle not drinking.
Train up to the distance/climate to not drink. Outside of straight up being outside of the rules for bottles in TT’s, you’ll be slower to use one. To quote what I heard in the start line at the regional USAC TT from the official to a guy “this is a TT, not a triathlon, no BTA or BTS, you need to go take that off”. Generally they let people ride framesets with hydration in the frame, but you have to remove the straw and not drink from it.
Bottles in a TT go on the downtube or seat tube bosses. Nowhere else. Folks have tucked camelbaks under the suits before, but pros at least I thought cannot do that anymore. It would be sneaky for a non-pro amateur event, and is innovative, but personally I feel like it’s one of those where you’re thumbing your nose at the ruleset a bit half hoping you don’t get caught. Meaning, I wouldn’t do it. It’s a freaking amateur TT, it isn’t going to make your life to use a camelbak or not.
Curious how much if any of the first post did you read?
I barely skimmed it and the gist I got was ‘I read the aerocoach data but my very small real world test is showing opposite results, is this possible? Not interested in actual fluid intake’
And yet here you are telling OP to go to a resource he mentioned already having read and explaining something that he never asked about.
So you’re reiterating that the OP doesn’t care about existing data, norms, or rules and wants to instead debate a very questionable field test. Good.
When that’s the mindset going into something (to ignore all the relevant stuff and let’s look at my junk anyway), the post I made is well deserved to be received by the person asking the question.
It’s not good science to say “ignore all that established stuff, look at my bad dataset”.
