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#701
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A note about the the head and head position. A sphere has a lousy coefficient of drag - approximately .5. Over the years, to improve the Cd of the human head (and protect it), time trial helmet design became very elongated and large. However, a larger helmet with a better shape may lower Cd but increase the frontal area and total drag force and is heavy, hot and not great at different wind angles.
So new helmets are smaller and offer good protection and better performance at different head positions and wind yaw angles.
Head position...I have attended several aero seminars and done a lot of aero testing. Head position is critical to riding fast. Any setup that causes the head to pop up into the wind is bad. So at a training session, we practice turtling the head by lowering it out of the wind and making adjustments to the setup that facilitates turtling the head.
Even with the most expensive fancy, very tight fitting helmet, popping ones head up into the wind is the kiss of death.
So new helmets are smaller and offer good protection and better performance at different head positions and wind yaw angles.
Head position...I have attended several aero seminars and done a lot of aero testing. Head position is critical to riding fast. Any setup that causes the head to pop up into the wind is bad. So at a training session, we practice turtling the head by lowering it out of the wind and making adjustments to the setup that facilitates turtling the head.
Even with the most expensive fancy, very tight fitting helmet, popping ones head up into the wind is the kiss of death.
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For the previous poster, to get at what Hermes said..........it has taken me about two months to finally get within a much nicer % of my road bike power on my TT bike. A few months of mostly TT riding with a few road rides mixed in. It will never be 1:1 IMO simply because a seated climbing position affords so much flexibility in how you can sit, squirm, move, change position, and breath that it's the way it is.
I remember before this, in TT position, I couldn't get within 100w of my road position 2min power. Maybe not a good example, but 100w is a boatload.
That took 3 months of TT riding and 2 months of a lot of TT specific workouts to bridge the gap. Even then, it's not 1:1.
Having been through it myself, instead of "easing into" the position as you do the work.........I'd go ahead and just do a mock TT outside or on Zwift to get a "TT bike" ftp. Then use that for your TT bike workouts in the position you intend to use.
I remember before this, in TT position, I couldn't get within 100w of my road position 2min power. Maybe not a good example, but 100w is a boatload.
That took 3 months of TT riding and 2 months of a lot of TT specific workouts to bridge the gap. Even then, it's not 1:1.
Having been through it myself, instead of "easing into" the position as you do the work.........I'd go ahead and just do a mock TT outside or on Zwift to get a "TT bike" ftp. Then use that for your TT bike workouts in the position you intend to use.
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#703
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Lots of info guys! thanks for all the responses. working on the position, i did a first ride with the new bars. Right now it is a lot too stretched out, so i am picking up a shorter stem from a teammate. Then i can start fiddling with the bar itself to get to a good baseline position. In the position i am definitely focused on a good turtle, sadly my shoulders are rather wide so getting a narrow shoulder position wtih low head will give me the best aero gains i think.
helmet will follow once i settle a bit more on the position, for now i will just keep riding with the Giro selector i already have. it's a bit oldschool with the long tail but don't want to start changing everything around at once.
helmet will follow once i settle a bit more on the position, for now i will just keep riding with the Giro selector i already have. it's a bit oldschool with the long tail but don't want to start changing everything around at once.
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So, year to year 2019 to 2020 for about a 10mi event my TT power is either identical or even 5w lower for live events. In 2019 I rarely trained on the TT bike. For the 2020 event I did a 2 month block of TT work.
Both indoor road and TT power are appreciably higher for 2020 than 2019. Same indoor bike 2019 and 2020. I setup my position on the indoors Cycleops stationary bike identical to the real bike both years.
I know outdoors is different, but I'm not seeing within 30 to 40w of the indoors figures.
It's a Stages left only on the outdoors bike that I also use on the road bike, I swap it TT/road. On road, it's hard to say. The surges are so high and shorter it's hard to tell the comparability to indoors.
I ran one of my last TT rides outside through the math and my CdA would have had to have been like .170 to make the power figure make sense. No freaking way.
I know you have to adapt to the power reading differences, but this to me is almost silly of a difference.
I had to add nearly 40w of power to arrive at a logical CdA guess for my position and equipment for the recent event.
Both indoor road and TT power are appreciably higher for 2020 than 2019. Same indoor bike 2019 and 2020. I setup my position on the indoors Cycleops stationary bike identical to the real bike both years.
I know outdoors is different, but I'm not seeing within 30 to 40w of the indoors figures.
It's a Stages left only on the outdoors bike that I also use on the road bike, I swap it TT/road. On road, it's hard to say. The surges are so high and shorter it's hard to tell the comparability to indoors.
I ran one of my last TT rides outside through the math and my CdA would have had to have been like .170 to make the power figure make sense. No freaking way.
I know you have to adapt to the power reading differences, but this to me is almost silly of a difference.
I had to add nearly 40w of power to arrive at a logical CdA guess for my position and equipment for the recent event.
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BTS, I am not sure that I fully understand. Do you use the Stages on the TT bike indoor and outdoor or do you use the Stages on the TT bike outdoors but Cycleops power inside?
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I made a chart and recorded power at 4 speeds on both, twice. And it is low. Now I know though.
The math from my dq TT race meant for the power to make sense, my CRR and CdA had to be about .003 and .170z. Not possible for the aero. Adding in the low power, it takes adding 30w to get the CdA in the calculator up to a more understandable .200.
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What is the hydration prep for a 40k/hour effort? I'm assuming good planning the day before and right before. Any tips?
You can carry a bottle, but I doubt the benefit of getting out of aero, fiddling, etc....versus going without.
You can carry a bottle, but I doubt the benefit of getting out of aero, fiddling, etc....versus going without.
#708
fuggitivo solitario
you def want something in that bottle, especially if you are racing in the South
take a sip before you go into a turn (or when your speed is the lowest).
Or use a camelpak tucked down your suit
take a sip before you go into a turn (or when your speed is the lowest).
Or use a camelpak tucked down your suit
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They have issues with BTS versus downtube? I own both for that bike.
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Hydration during a longer ITT is very individual. It is difficult to measure the drag effect of carrying water in a bottle due to the impact of the rider although you could try a coast down test. As I recall, camelbacks on your back are illegal under UCI rules and maybe anywhere on the body, if you care about UCI.
I have not taken a drink of water on 20k, 30k or 40K ITTs but I have carried water to drink at the end. It is too hard to get any water down while breathing hard and it really throws off the rhythm and one has to replace the bottle..or not. Some carry water and take a drink at the turnaround and throw the bottle on the ground.
For world hour records, there is no water on the bike and there is a lot of practice getting the hydration right before record attempts. Too much intake before generates the feeling that one has to pee during the race. Hour records are attempted with the ambient as high as the athlete can stand to lower RHO.
In the book Good to Go, it discusses hydration and how drinking is but yet another myth that runners and cyclists cling too. It is true that dehydration is bad but the human body has ways to counter dehydration and an hour or less is not much time. YMMV.
I have not taken a drink of water on 20k, 30k or 40K ITTs but I have carried water to drink at the end. It is too hard to get any water down while breathing hard and it really throws off the rhythm and one has to replace the bottle..or not. Some carry water and take a drink at the turnaround and throw the bottle on the ground.
For world hour records, there is no water on the bike and there is a lot of practice getting the hydration right before record attempts. Too much intake before generates the feeling that one has to pee during the race. Hour records are attempted with the ambient as high as the athlete can stand to lower RHO.
In the book Good to Go, it discusses hydration and how drinking is but yet another myth that runners and cyclists cling too. It is true that dehydration is bad but the human body has ways to counter dehydration and an hour or less is not much time. YMMV.
Last edited by Hermes; 03-06-20 at 08:59 AM.
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#711
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There are also photos from 2016 Worlds, showing riders using bladder + hose in a race. Definitely in a road race, can't remember if one was used in the TT as well. Also don't know if that was an one-time exception.
No idea about btwn-the-pads placement of bottles. My hunch is that it's not allowed. Downtube should be fine
ETA: see the following (re: usage of Camelbak in an UCI ITT/TTT)
https://forum.slowtwitch.com/forum/S...world#p6145897
https://www.eurosport.com/cycling/bl...57/story.shtml
https://cyclingtips.com/2016/10/came...heat-in-qatar/
Last edited by echappist; 03-05-20 at 04:27 PM.
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I don't have first hand experience with people using Camelbak in USAC races. I know someone who has used one in a USAC TT though.
There are also photos from 2016 Worlds, showing riders using bladder + hose in a race. Definitely in a road race, can't remember if one was used in the TT as well. Also don't know if that was an one-time exception.
No idea about btwn-the-pads placement of bottles. My hunch is that it's not allowed. Downtube should be fine
ETA: see the following (re: usage of Camelbak in an UCI ITT/TTT)
https://forum.slowtwitch.com/forum/S...world#p6145897
https://www.eurosport.com/cycling/bl...57/story.shtml
https://cyclingtips.com/2016/10/came...heat-in-qatar/
There are also photos from 2016 Worlds, showing riders using bladder + hose in a race. Definitely in a road race, can't remember if one was used in the TT as well. Also don't know if that was an one-time exception.
No idea about btwn-the-pads placement of bottles. My hunch is that it's not allowed. Downtube should be fine
ETA: see the following (re: usage of Camelbak in an UCI ITT/TTT)
https://forum.slowtwitch.com/forum/S...world#p6145897
https://www.eurosport.com/cycling/bl...57/story.shtml
https://cyclingtips.com/2016/10/came...heat-in-qatar/
#713
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Start 2 or 3 days before. Also, try to get plenty of sleep two nights before the event.
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Ordered my bar/round stock to get rid of the Felt DA splined stem silliness. Got the Aeria Ultimate stem on sale for $100. It's heavy but it super aero.
I'm going to make two base mounts for the Bayonet fork/stem mounting area. One that's easier to fit in a UCI box, and one that won't be. If I get the mount out front of the head tube, the reach coord will likely exceed the single exception distance. If I mount it a touch higher on top, it won't.
I may mount it there anyway as I think the stack will be too low down and out front anyway. I'd have to run all my stack risers at that point.
I'm going to make two base mounts for the Bayonet fork/stem mounting area. One that's easier to fit in a UCI box, and one that won't be. If I get the mount out front of the head tube, the reach coord will likely exceed the single exception distance. If I mount it a touch higher on top, it won't.
I may mount it there anyway as I think the stack will be too low down and out front anyway. I'd have to run all my stack risers at that point.
#715
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Would love to see more photos and detail of the Bayonet fork/stem mounting plate thing. That's the part that (to me) sounds the most technical. Keep us posted!
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Will do. I will take good pics.
Stock and stem arrived. I think the Aeria Ultimate they were selling at deep discount were all missing the $5 steerer tube shim. Had to buy one on Amazon for $7 last night.
Once that comes in I will start up on work.
Stock and stem arrived. I think the Aeria Ultimate they were selling at deep discount were all missing the $5 steerer tube shim. Had to buy one on Amazon for $7 last night.
Once that comes in I will start up on work.
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First attempt at making the bracket was a failure. I transferred the hole locations poorly. I wanted to save as much material as possible in strength so chose to start again instead of increasing sizes or rounding things out. That's why I bought an 18" long bar to work with!
Second attempt is going better. I have the three mounting holes transferred and countersunk and test mounted the full bar without cutting that yet. I have the mount point for the stem "rod" started. For that I went with a really big fastener. I don't have a bit big enough to countersink that so will need to shave about a mm off the countsunk head on the outside of the fastener. The size of the bar and fasteners are total overkill, but, that's a good think in this area!
Next step is to setup the mounting rod for the stem to clamp to. Once that's good, I'll work on cutting the mounting plate from the large bar and rounding off things nicely.
The extra thickness of the mounting plate versus the original hollow alum spline assembly is reassuring even with the fastener holes. As that piece also had the same size mounting holes obviously.
It's looking that this will work for sure. I just need to measure thrice and cut once to keep it clean and solid.
Overall due to the drop in stack on that stem, plus the extra stack up in the thicker mounting plate.........it'll come out to lowering stack by about 1/4". That's fine. I have more stack spacers for the base bar risers.
Second attempt is going better. I have the three mounting holes transferred and countersunk and test mounted the full bar without cutting that yet. I have the mount point for the stem "rod" started. For that I went with a really big fastener. I don't have a bit big enough to countersink that so will need to shave about a mm off the countsunk head on the outside of the fastener. The size of the bar and fasteners are total overkill, but, that's a good think in this area!
Next step is to setup the mounting rod for the stem to clamp to. Once that's good, I'll work on cutting the mounting plate from the large bar and rounding off things nicely.
The extra thickness of the mounting plate versus the original hollow alum spline assembly is reassuring even with the fastener holes. As that piece also had the same size mounting holes obviously.
It's looking that this will work for sure. I just need to measure thrice and cut once to keep it clean and solid.
Overall due to the drop in stack on that stem, plus the extra stack up in the thicker mounting plate.........it'll come out to lowering stack by about 1/4". That's fine. I have more stack spacers for the base bar risers.
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Check it out:
It took a good bit of work last night to finish, but ask and ye shall receive...........
It dropped the stack probably a good 3/4 to inch, but I have plenty of risers to play with for later. I'll ride it as-is to test it out and get new fit video taken of the stack. Reach is identical (barring stack change) due to fact I designed it to mount so the reach wouldn't change. This is the 70mm Aeria Ultimate. It fit without modification to the "PDQ" style open mold TT bars from Selcof/PlanetX.
Details on the mount: It's 1/2" thick aluminum. I drilled and countersunk for the original three mount points by transferring using the original spline stem POS. Then, I added one last mount point countersunk on the opposite side. I tapped the new 1/2" thick aluminum from the underside for a huge M8 high grade bolt. Then, I drilled and tapped some 1" aluminum round stock. I then cut that to length for the clamp area of the stem. I threaded that aluminum rod stock to the M8 bolt sticking up nice and tight. As a final triple check on staying in place, there is an M8 nut on top hidden just under the inside of the clamp area of the stem. I had to use a 1" to 1 1/8" stem shim to do this. 1 1/8" round aluminum stock was on long back order on good prices on stuff in shorter lengths like one foot long.
The Aeria Ultimate stem has a pretty wicked drop to it, negative rise. So, this meant I needed to cut the mount plate at a 45 degree angle on the front to match that slope of the underside of the stem. I did that instead of cutting it closer and straight so just in off chance the stem ever loosens, that part of the mount will still steer the bike. Your normal stems on a steerer tube can't do that, if they loosen up it's done for.
I love the look of it so far, super clean.
#719
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very cool!!!!
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HED Jet 9+ on the way. So I can go full crazy when it isn't too too windy.
A bit annoyed at Aerocoach though. I know backorders and such, but you can at least send an update email to customers waiting once every other week or two or something. You can probably automate it even.
A bit annoyed at Aerocoach though. I know backorders and such, but you can at least send an update email to customers waiting once every other week or two or something. You can probably automate it even.
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Well, the Jet 9+ front came in as not a 9+. It came as the 76mm deep and 23mm wide HED "express" wheel.
Still silly fast front wheel for me, but not a 90mm Jet 9+. I may keep it. I may sell it and still get the 9+. It was a good price, so no true loss.
I just blew it again tonight. Tired of swapping the power meter road to TT bike, and also having it be wrong length by 2.5mm (it is a 167.5, not a 170). I got a good deal on a Quarq including 165mm arms.
I'll sell my 170 crank with 54T 1x chainring for a few bucks. Got a Rotor no-Q aero 54T 1x ring to go with the Quarq.
All in it cost me $550 including the bottom bracket bearing to fit the Quarq. Not terrible for true dual leg.
Still silly fast front wheel for me, but not a 90mm Jet 9+. I may keep it. I may sell it and still get the 9+. It was a good price, so no true loss.
I just blew it again tonight. Tired of swapping the power meter road to TT bike, and also having it be wrong length by 2.5mm (it is a 167.5, not a 170). I got a good deal on a Quarq including 165mm arms.
I'll sell my 170 crank with 54T 1x chainring for a few bucks. Got a Rotor no-Q aero 54T 1x ring to go with the Quarq.
All in it cost me $550 including the bottom bracket bearing to fit the Quarq. Not terrible for true dual leg.
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I've got a HED Stinger 9 front wheel if you're interested. Also a Jet Disc (10 speed, but I think it's pretty easy to convert to 11). I'd be willing to let them go for a pretty cheap price if you're interested.
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Thanks. I have a rear HED Jet disc now. 11 speed. As for front, I doubt I would train much on something 9 deep but given my glue skills are crap and nobody around me is known for their glue skills.......I'm sticking with clincher and tubeless ready. Any gains in crr of a super nice tub I would lose in my junk glue setup.
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Thanks. I have a rear HED Jet disc now. 11 speed. As for front, I doubt I would train much on something 9 deep but given my glue skills are crap and nobody around me is known for their glue skills.......I'm sticking with clincher and tubeless ready. Any gains in crr of a super nice tub I would lose in my junk glue setup.