How much faster does a TT bike make you?



JTE83

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This is a question for those people who have a good racing road bike and then a decked out time trial (or triathlon) bike. Tell us how fast you are avg speed and top speed on your road bike and then on your time trial bike (assuming same course, no winds, or flat roads). Try to give a description of the build of your bikes, especially if your TT bike has disk wheels. I assumed you were riding in the drops on the road bike and in the triathlon position on the TT bike.
 

Cyclist14

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I don't have a dedicated time trial bike and for the next few seasons I'll probably buy some clip-ons and a cheap disk wheel



But I am sure you could shave of a few seconds on a 20K TT, maybe a minute on a 40K TT.
 

wardie2000

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I have one of each both Orbea and i believe that it does make a difference over a longer distance, but the problem with a TT bike is that over a certain distance it starts to become uncomfortable if you have a true aero position.

This would then give the advantage to the standard road bike as you have more position options.

My times for 10mile do differ significantly depending on the bike.
I used my Road bike the other day in a TT to get some power data and did the worst time for the season. I clocked an average of about 42kmh, giving a long 22min
on the same course a week later i averaged 46kmh on the TT bike, giving a long 20min.

You can see the difference
 

rv

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JTE83 said:
This is a question for those people who have a good racing road bike and then a decked out time trial (or triathlon) bike. Tell us how fast you are avg speed and top speed on your road bike and then on your time trial bike (assuming same course, no winds, or flat roads). Try to give a description of the build of your bikes, especially if your TT bike has disk wheels. I assumed you were riding in the drops on the road bike and in the triathlon position on the TT bike.

a tt bike, in and of itself, may not make you any faster. some of the things being sold as tt bikes are not very aero because of the shape of the tubing. a road bike with aero bars and aero wheels can be just as fast. there is lots of data out here estimating how much time a particular piece of true aero eqipment will save you over 40k. the most important factor is position, and popular thinking now says being narrow is more important than being low.

assuming you have a tt bike, it kind of goes like this ...
1. position
2. position
3. position
4. aero front wheel (greater than 38mm deep, 50mm is pretty standard)
5. aero rear or disk
6. helmet
7. skinsuit
8. shoe covers
 

dhk

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Sep 1, 2003
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rv said:
a tt bike, in and of itself, may not make you any faster. some of the things being sold as tt bikes are not very aero because of the shape of the tubing. a road bike with aero bars and aero wheels can be just as fast. there is lots of data out here estimating how much time a particular piece of true aero eqipment will save you over 40k. the most important factor is position, and popular thinking now says being narrow is more important than being low.

assuming you have a tt bike, it kind of goes like this ...
1. position
2. position
3. position
4. aero front wheel (greater than 38mm deep, 50mm is pretty standard)
5. aero rear or disk
6. helmet
7. skinsuit
8. shoe covers
Agree position is by far the important thing. At the Td Georgia TT this spring, I noticed lots of variation in the pros positions. As you likely know, Lance sits up fairly high, with an arched back, while others have the classic flat back. A narrow profile, with tucked in elbows, arms, and knees did appear to be common.

Also noticed various combinations of wheels on the TT bikes. Perhaps this was due to the climbing on the 18.6 mile course. Lance used a Hed tri-spoke front and a disc rear, but other riders were on spoked wheels of varying rim heights.
 

sambo76

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Over our clubs 18.5km TT course (undulating and tough) I am around 2.30 faster using my TT bike under same conditions and HR values/intensity.

My road bike is a Avanti Corsa Elite, Ultegra 9spd, Ultegra/open pro wheels.

Mt TT bike is a Cervelo P3C, Ultegra 10, Zipp 808's.

As others have said Position is most important but at the same time if you are not comfortable it is pointless as you will not ride well due to the distraction. My cervelo is set so I can ride Ironman which means I am comfortable for the whole 180km not just the first 20k's or so.
 

artmichalek

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dhk said:
Also noticed various combinations of wheels on the TT bikes. Perhaps this was due to the climbing on the 18.6 mile course. Lance used a Hed tri-spoke front and a disc rear, but other riders were on spoked wheels of varying rim heights.
I think you're right about the climb. I wasn't there, but from the looks of the course profile there was no clear advantage to being either lighter or more aero. As for aerodynamics, position is key. The drag force acting on your body is huge compared to the bike. I can't help but laugh ever time I watch something like "Chasing Lance", and they proudly show some massively expensive CFD analysis of a TT bike with no rider on it. CFD is pretty inaccurate to begin with, and when you leave out the biggest part of your system all you're left with is some pretty colors and large bill. Until you have your body position tuned for the optimum combination of comfort, power output, and aerodynamics, the bike doesn't matter much.
 

DJTempo

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Before I get into this, let me explain that I would classify myself as a "fast recreational rider". My work schedule keeps me from training as I would need to be competitive. Despite that, I own 3 bikes. My "rainy day" bike is a 1998 Trek 1000, redone a couple years ago with Ultegra and running Spinergy Spox. I have a 1999 Trek 5500, completely redone (paint and all) with D/A, FSA carbon cranks, and I just replaced my Rolf VP's with FSA RD600's. I also have a Trek Team Time Trial frame with a HED disc rear, tri-spoke front, HED carbon TT bars and everything else D/A. Same course, TT first, then 5500, another day 5500 first, then TT, comparible winds, etc, I'm about 2.5 mph faster on the TT bike than the 5500. I haven't timed anything with the new FSA RD600's, I had the Spinergy's on the 5500 when I did the timing a few months ago. If it's "aero", you'll be faster. You may still fall off on the hills (like I do, it's pretty flat here in Dallas), cause "aero" doesn't help you there, but you'll have an easier time keeping up with your buds, and be able to expend less energy for a given speed in any case. OK, not very "scientific", but I know I'm working less and going faster on the TT bike. - Chip
 

wilmar13

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wardie2000 said:
I used my Road bike the other day in a TT to get some power data and did the worst time for the season. I clocked an average of about 42kmh, giving a long 22min
on the same course a week later i averaged 46kmh on the TT bike, giving a long 20min.

sambo76 said:
Over our clubs 18.5km TT course (undulating and tough) I am around 2.30 faster using my TT bike under same conditions and HR values/intensity.

OK this is exactly what I want to hear after doing a 22:30 10 mile TT recently... "well if only I drop a few $K on a special purpose bike I will be down to 20:30" :D

But just for comparison both you guys are comparing with your road bikes totally standard, no aero bars and 32 spoke wheels right? Is it possible there was some psychological aspect like you feel slower on a road bike during a TT, which could have resulted in part of the difference? Using the widely accepted N+1 theory for determining the optimum # of bikes one needs to possess, I am ready to buy a TT bike, but I can't believe I could really drop more than 10-15 seconds off a 10mile TT by doing so (compared to aero bars and wheels on road race bike).
 

bikeguy

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May 31, 2004
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JTE83 said:
This is a question for those people who have a good racing road bike and then a decked out time trial (or triathlon) bike. Tell us how fast you are avg speed and top speed on your road bike and then on your time trial bike (assuming same course, no winds, or flat roads). Try to give a description of the build of your bikes, especially if your TT bike has disk wheels. I assumed you were riding in the drops on the road bike and in the triathlon position on the TT bike.

I just got an Argon 18 TT mercury frame but have yet to put the components on (which I'll probably do myself, since I'm short of cash). I have two very low traffic TT loops I use so I'll let you know how it runs compared to the Bianchi Nirone road bike I use. I have a single Zipp 404 to use as a front wheel and FSA Vision 29 cm aerobars. Right now it's too muddy and dirty to use the TT frame (the rear wheel cutout will gum up in minutes) so I'll post a review up in maybe a month.

-Bikeguy
 

gclark8

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I agree with the parameters set by the original poster, however not all of us are young and flexible. I am not able to use drops (road bike) or aero bars (Tri bike).

Having said that the two frames are quite different, the road bike uses 700x23c tyres, the rest much the same as the Tri bike. The TRY bike uses 650c Velocity deep-v wheels with 20 paired bladed spokes. I have yet to ride them over the same course, but the Tri bike certainly accelerates faster and climbs hills easier.

I do intend start training on the Tri bike soon and to try a TT base bar in the future if my balance improves, but until then both will have similar flat bars and shifters.
 

DJTempo

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Also, let's put it this way... the guys that do have the money, and the time, and the physiques to well take advantage of these aero toys do use them to great advantage. Good ole Greg LeMond won his final stage TT, and the Tour along with it, due to the new fangled aero bars he bolted onto the bike. Lance spent hours and who knows how much money deciding to use a dimpled aero suit for his TT runs.

Common sense should tell you that a "disc" wheel will be faster than a regular spoked wheel, even a spoked wheel like the HED-3. Of course, HED will promote the fact that their HED-3 is the fastest thing out there, only slower than their disc.

Not to get any engineers mad at me, but aerodynamics is a fairly simple concept. Drag costs you energy and/or time, depending on how you measure it and what your limiting factor is. The more aero you are, the faster you'll go, and/or the less energy your expend doing it.

Sure, bolting on new aero-bars may only make you 2 seconds faster, and there is (very arguably) the psychological factor, but you will be faster. And in races that are timed with stopwatches that have a 1000's of a second accuracy, the winner can and often will be the one who has the best equipment.

Of course, you could put Lance on a Schwinn Varsity 10-speed and he'd still beat all of us. But he's got the genetically better motor.
 

artmichalek

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DJTempo said:
Common sense whould tell you that a "disc" wheel will be faster than a regular spoked wheel, even a spoked wheel like the HED-3. Of course, HED will promote the fact that their HED-3 is the fastest thing out there, only slower than their disc.

Not to get any engineers mad at me, but aerodynamics is a fairly simple concept. Drag costs you energy and/or time, depending on how you measure it and what your limiting factor is. The more aero you are, the faster you'll go, and/or the less energy your expend doing it.
Pure drag reduction isn't everything. A disc may be faster but it will get you killed in a cross wind. A convenient reality for HED, which wants everyone to show up for a race with a whole truck load of wheels for different conditions. Added drag may always require more power, but the relationship is cubic. An elite pro is TTing at 35mph, and those little changes are going to be much more significant than they are for those of us who are only doing 25.
 

DJTempo

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I'm not saying the aero stuff doesn't have it's drawbacks. I won't take out the TT bike if there's more than about a 10 mph cross wind. The bike gets too squirlly (sp?). But we're losing sight of the original question and premise: aero equipment WILL make you faster. You suggested that it "may" make you faster. It's not that it MAY require more power, it absolutely WILL require more power. Now, the benefits might not be measurable in our road based laboratories, but they are measurable.

Chances are, adrenaline will be a bigger performance boost if you're doing your first TT though. Or, you could slam a couple Jolt Cola's before you start. The added carbs will help too.

Don't fixate on the equipment, get out and ride...
 

wilmar13

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DJTempo said:
Not to get any engineers mad at me, but aerodynamics is a fairly simple concept.
What about reading comprehension, how simple of a concept is that? :p

Just kidding, I thought this thread is about the advantages of a pure TT bike vs. using a road bike with aero add ons... but looking back at some of the posts, I can see others are looking at it in terms of what are the aero add-ons worth.

I am interested in what it is worth to have a TT specific frame, as you can do most anything else to your standard race/training rig (discs, bars, helmet, skinsuit, etc.).
 

Borg

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Jan 27, 2004
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Do something about the hair maybe Mr Sharpelle...that's gotta be good for ~ 6 kph.
 

wilmar13

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Borg said:
Do something about the hair maybe Mr Sharpelle...that's gotta be good for ~ 6 kph.
Try 8kph... I find it beneficial to train with it, so that when I don the Louis G Prologue helmet on race day it feels like I am flying. I learned it from the same group of people that use lead water bottles while training for hill climbs.
 

DJTempo

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Yeah, it's easy to lose sight of the purpose sometimes.

"By the numbers" any aero component is going to be faster than it's non-aero counterpart. Lots of conditions apply though.

I bought my Trek TT frame because (and most people I tell this to find it hard to believe) it is the most comfortable frame I've ever sprawled my body across. Don't know why, just my physique. I also find my Yamaha R6 to be a lot more comfortable than my previous Honda CBR600F4i. It's just the way it fits.

Point is, comfort has a lot to do with frame preference. You WILL be faster on a frame you're comfortable on as opposed to a frame you're not. Aero or otherwise.

An aero frame is advantageous, no question. But not if you're not comfortable, and not if you're not riding it in the conditions it was designed for (basically level course, little or no wind).

The arguments can flip flop either way. You're either trying to talk yourself into buying it, or you're trying to talk yourself out of it. If you have the means, and the purpose, go ahead and buy the thing. (he who dies with the most toys wins). I have absolutely NO reason to own my (what was then) $2800 Trek TT frame with it's extra $3000 worth of components and wheels. But I love it. It's comfortable, and I dig the looks I get rolling up to the start of the Richardson Bike Mart group rides... and I only ride with the 2nd starting group.

On your left...
 

artmichalek

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DJTempo said:
You suggested that it "may" make you faster. It's not that it MAY require more power, it absolutely WILL require more power. Now, the benefits might not be measurable in our road based laboratories, but they are measurable.
I'm not sure exactly where I made the assertion that drag didn't always influence power requirement. Perhaps you could point it out for me? I merely suggested that small aerodynamic improvements will produce negligible gains for most people.