How much does aero help for TTs?

[David Martin]

An interesting article with real world data..

www.cyclingnews.com - the world centre of cycling

[vorsprung]

Interesting for time trialists going at 25mph maybe

The rest of us want to know- do the clip on tribars really make a difference at 30kph into a headwind or am I just imagining it?

[andygates]

Hm, so, my clip-on aerobars are good, but the next big saving will either be a TT bike or a sperm hat!

[mattc]

Interesting for time trialists going at 25mph maybe

The rest of us want to know- do the clip on tribars really make a difference at 30kph into a headwind or am I just imagining it?

Deffo. I get about a 1.5-tooth difference at the back.

If your air-speed is 25mph, you will get pretty much the same benefit  as the TT-ist doing 25mph on a "float" day.

Plus it is one more handlebar position to use for variation on long rides. Which is nice.

[BornAgainCyclist]

When I fitted tri-bars to my road bike a couple of years ago, I reckon it knocked a minute off my 10 mile time. At the time I was doing consistant times of around 26:30 on the Q10/26 (well I am coming up to 65), these times were reduced to around 25:30 as soon as the tri-bars were fitted.  They seem to knock off most seconds for your £.
Just ordered a new carbon road bike from Ribble, which I suspect will cost many more £s per second - but I got bored with the old bike.
Last summer a club-mate (doing similar times to myself on a road bike with tri-bars) bought a new carbon Time Trialler and knocked a minute off his time (but it cost him £4K).
If you use your tri-barred road bike for other rides, the pads fitted to the top of the bars get in the way and prevent you riding 'on the tops', which is a real pain.

[MattH]

If you use your tri-barred road bike for other rides, the pads fitted to the top of the bars get in the way and prevent you riding 'on the tops', which is a real pain.

I use Airstryke bars, where the pads flip up out of the way. They are not the lightest (though surprisingly not the heaviest either) and work pretty well, but I had to glue some bits of old inner tube into the hinge mechanism to stop it rattling.

[David Martin]

If you use your tri-barred road bike for other rides, the pads fitted to the top of the bars get in the way and prevent you riding 'on the tops', which is a real pain.

Mine made a big difference - about 2 mins.

As to the pads getting in the way - I moved my computer etc onto bar ends on the tri-bars (in between the handlebars and where I hold them. This means that the tri- bars take up no more room than the computer/hrm do without the tri bars fitted.

..d

[BornAgainCyclist]

Thanks Matt/David
Both worth consideration when the new bike arrives (Tuesday - so I'm told).

[vorsprung]

re- the pads getting in the way issue.
I had some of the "fold away" pads and found they still got in the way
So I entirely removed the pads and rest my elbows on pipe lagging at the middle of the bars
It seems more comfortable ( to me ) and is slightly lower and therefore better

[simonp]

So if I can maintain 229W for 24 minutes on a TT bike I can do a 24 minute 10?

I know I can do 200W for 30 minutes.  Might be tempted to shove the PowerTap on the Madone at the start of the season and get some data.

[mattc]

So if I can maintain 229W for 24 minutes on a TT bike I can do a 24 minute 10?

... but you still won't win anything*, so the point is?



*unless I'm the only other rider.

[simonp]

So if I can maintain 229W for 24 minutes on a TT bike I can do a 24 minute 10?

... but you still won't win anything*, so the point is?



*unless I'm the only other rider.

I'd like to improve on 27th out of 31 riders.

Interestingly it seems there's a cluster of times around 28+ minutes (28.01, 28.05 (me), 28.29, 28.56, 28.57) but there's not so many riders just a bit faster - 27.27, 26.57, 25.55 shows a much wider spread and then they bunch again.  I'm wondering if that's the difference between taking it a little bit seriously and just showing up.

24'-odd times would at least have an air of mid-table respectability. 

[mike]

I've got to work on getting lighter and more aero in 2009...  300+W for 25 minutes is doable but cos I'm built like a brick outhouse I'm still bloody slow.  

[mattc]

24'-odd times would at least have an air of mid-table respectability. 

I suggest you work on maintaining short 28s with more and more audaxing tat hanging off the bike

[nmcgann]

So if I can maintain 229W for 24 minutes on a TT bike I can do a 24 minute 10?

I know I can do 200W for 30 minutes.  Might be tempted to shove the PowerTap on the Madone at the start of the season and get some data.

That test does assume an unrealistically smooth, flat and minimally windy course though. Real road courses are nothing like as good as that.

I'd have said that you need around 30W more for sub-25m unless you are small, thin and very aerodynamic.

It took me 283W to do a 24m29s 10 on our flattest local club course and I'm skinny and pretty aero, although a bit tall (6ft1in) for minimum frontal area. That's with a TT bike (ordinary wheels tho'), skinsuit and pointy hat.

Neil

[peter carter 2]

I can't quote the sources, but this study does seem to replicate earlier ones. Tri bars, as they were once known, are the cheapest way to improve your times.