Road bike V TT Bike?

[Grandfondo]

How much time difference would there be over 10miles with the same rider and same conditions?

[Celtic Dragon]

Obviously it depends on the riders output. I'll see if I can find the video I watched last week. Using hrr figures and your distance its about 25 seconds.

[Grandfondo]

A proper TT bike with disk wheel and obviously same course and same rider.
Celtic D is that 25seconds a mile?

[Fourmotion]

Ok, this is as scientific as I can offer.

I did the same 10 TT twice, 1 week after another, in very similar conditions. First week on a road bike, second on a TT bike. My watts were only slightly down which is more than likely down to positioning anyway, so the effort is probably comparable.

The TT bike was borrowed, and only the saddle height was adjusted, so it wasn't a perfect fit. I wore an aero helmet. I used the same wheels as the road bike effort. I wore the same clothes.

So I'm saying 50 seconds to a minute. I'm sure someone can give a reasoned time saving for deep rim wheels, a fitted bike, and a speed suit.

Road
http://www.strava.com/activities/155184884

TT
http://www.strava.com/activities/158112805

[Celtic Dragon]

Grandfondo said:

A proper TT bike with disk wheel and obviously same course and same rider.
Celtic D is that 25seconds a mile?

Thats over 10k. The vid is done over 40k, and turns out to be 1min 40 over 40k

[Celtic Dragon]

This was the video I mentioned

https://www.youtube.com/watch?v=LMLKcHyHPrc

This one might be worth a watch too.

https://www.youtube.com/watch?v=SAy6pumNlFQ

[Grandfondo]

I was thinking about 10 seconds per mile?

[okgo]

Around 1 minute 30 for me switching from aero road bike and skinsuit to top end TT bike + helmet and skinsuit. That was right off the bat.

[Grandfondo]

Yep,that sounds about right.

[Barchettaman]

http://a2wt.com/research.pdf

[Barchettaman]

http://www.bikeradar.com/road/gear/article/how-aer...

[S10GTA]

I was always under the impression that you would save close to 2 mins on a TT bike over a road bike

[okgo]

S10GTA said:

I was always under the impression that you would save close to 2 mins on a TT bike over a road bike

As with anything, its a very hard question to answer for everyone. Some people on TT bikes have such woeful positions that they're actually not that much more aero, and in the TT position they find they cannot put out the same power, I've known people to go slower on a TT bike than a road bike!

Over the time I've had a TT bike I've refined my position to a point now where its probably 1 minute faster over a ten than it was when I first got on it, and that is without changing any of the equipment (bar a more expensive skinsuit)

[Greenish]

I had a brief go on a friends TT bike and remember it feeling peculiar even in a straight line. Is this something you get used to?

[okgo]

Greenish said:

I had a brief go on a friends TT bike and remember it feeling peculiar even in a straight line. Is this something you get used to?

Yeh it does take a little while, but you certainly get used to it. They're one of those things that feel stable the faster you go I think.

[whatleytom]

Greenish said:

I had a brief go on a friends TT bike and remember it feeling peculiar even in a straight line. Is this something you get used to?

Definitely, I can remember it feeling very odd to begin with, you absolutely get used to it though. It is a different style of riding though, you have to think up the road a fair bit more than riding a normal road bike.

With regards to power, I find it easier to sustain power on my TT bike, and can get more power than on my road bike, I prefer being much more over the BB rather than behind it as on the road bike. Probably says more about my road bike fit than anything else though.