brundle_fly

How much time could you knock off a 40k ride.I read quite a few people being able to do 25mph+ on a TT bike,but no so much on a road bike

manutd

Not very much time if the 40km is up the side of a mountain.....

qr409tz8

4.382MPH faster.

tallteacher

Not at all...it's the placebo effect

Busta Quad

Don't forget to ask how much less comfortable a TT bike, and a good aero position on said bike, is...

Homebrew01

Depends on how much more efficient you are on the TT bike compared to your road bike.

merlinextraligh

Standard road bike, no aerobars, rider in drops, versus, full on TT bike, aerobars, good position, and aero wheels, saves a couple of minutes in a 40k TT.

In Kruezotter, 25 mile TT, 300 watts, 157lb rider:

Road bike in drops, 24.3mph, 1hour 1 minute 43 seconds.

Triathlon bike, 58 minutes, 8 seconds.

I don't know the precise assumptions the calculator makes, but that amount of difference is fairly realistic . Although, I think you could argue that its slightly overestimates the difference.

merlinextraligh

And if you don't practice a lot on the TT bike, it's likely that while you be more aero, you'll put out less power. I can never put on the same watts on my TT bike that I can on my road bike.

StanSeven

A minute to 1.5 minutes with aero wheels and the same for aero bars. So I think 2-3 minutes.

One thing people forget is staying in the drops on a road for the duration gives a big gain

manutd

+1 on this

I've put my TT bike on a computrainer and didn't have close to the same wattage I was putting out on my road bike due to the fact (I think) that I hadn't been riding my TT bike regularly and you use different muscles. I will say that in real life situations on the road in the wind the TT bike is slightly faster (or at least less effort is needed to maintain speed levels)

badhat

i have my TT and road geometries set up very similar, just rotated forward a hair on the TT bike, so that the muscle action and core muscle activation are pretty similar.

it has the added benefit of giving me a pretty aero position on my road bike.

Aeolis

IMO they are faster over the short term. Long term the fit
Will probly wear you down.

jsutkeepspining

my tt bike is fast, but i produces a lot less power, so while i might only do 27-28.5 on the tt bike, i can do 25+ on the road bike. I produce about 40-50 watts more over most tt's no my road bike versus my tt bike.

lungdoc

A bit of an academic question if you aren't doing time trials (unless you've got a really tight commuting schedule ). I assume if you are doing time trials you'd have or get a TT bike. If not the absolute speed really shouldn't matter. Or am I missing something?

fa63

How Aero is Aero?

Cliffnotes version: 60-70W less at 25 mph going from a normal road bike setup to a full TT setup.

Scorer75

I got this info from this forum a while back. I do not have a source and cannot verify the accuracy, but it's interesting. Best guess is it was put out by Cervelo based on wind tunnel testing they did. YMMV

Required output to maintain 45 kph on a:
Standard road bike, hands on hoods = 465 Watts
Same bike, hands down on the drops = 406 watts
Same bike with aero bars = 369 Watts
Same bike, triathlon position (5.5 cm lower bar, saddle forwards)= 360 Watts
Same bike, as above, with 2 tri spoke wheels = 345 Watts
Cervelo TT bike with 2 tri spoke wheels = 328 Watts
Cervelo TT bike with tri spoke front & disk rear = 320 Watts
Cervelo TT bike, tri spoke front & disk rear + aero helmet = 317 Watts
Cervelo TT bike, same as above + skin suit = 307 Watts
Cervelo TT bike, same as above, with saddle pushed back 3cm = 293 Watts

From 465 to 293 watts!! That's obviously a reduction of 172 Watts just from aero stuff!!

AdelaaR

Speak for yourself, please.
I personally feel that, for me, a position on good aerobars is always more comfortable than a position on anything else.
I ride my TT bike as primary bike, btw.

AdelaaR

OP, whatever the difference is depends on many factors ... but it sure isn't going to be huge.

My fastest average speed ever over 10k on my TT bike was 27.2mph.
On exactly that same course ... my fastest ever average speed on my hybrid was 25.3mph.
A roadbike, I suspect, would be somewhere in between those.
As you can see the difference is small.

ivan_yulaev

48 minutes 30 seconds with a lowracer recumbent, same effort

escarpment

I have seen that cervello data before and it always makes me wonder.

I feel like I can get more aero while im riding on my hoods as I can mimic a tri position, where as when im in the drops my body is just as low but i feel like more of my arms are exposed.

I think we all must think about the price differences between achieving a more aero position on our bikes. Or buying speed with trispoke/disk wheel/ skin suit/ tri helmet...

patentcad

1-2 mph, I know this from personal TT experience where I'm faster than most (not all) of the guys on regular road bikes, even though I know I'd never beat most of them on a regular bike. I am faster than most of them on the same TT course when I'm on the TT bike however.

rpeterson

Going from my slightly aggressive road bike to my stupid aggressive tri bike I have a difference of ~75 watts at 25mph using the same wheels, tires, helmet, and clothes.. I could probably cut that a bit by making my road position a bit more narrow and low, but I'd have to make a lot of handling and comfort compromises to equal the tri position.

I'm quite comfortable on my tri bike as well.