Calling all Time Triallists

[VamP]

This was waiting for me at home

Upon unwrapping I found a bunch of goodies, all very well wrapped

and head and shoulder above the rest this little beauty

so far so good

The carbonzone package includes frame, fork, headset, bars, brakes and seatpost. I was somewhat concerned about what the bars would be like, but they are actually really good. Shifters, brakes cables etc have now been ordered, and the build will begin as soon as they get here.

 

[User482]

I seem to recall reading that the things that make the biggest difference are a skinsuit, aero helmet and aero bars. The TT frame, wheels etc only give you a very small aero advantage over ordinary road kit.

 

[VamP]

Position makes the biggest difference. Hence dedicated TT bikes over clip ons.

 

[Rob3rt]

I seem to recall reading that the things that make the biggest difference are a skinsuit, aero helmet and aero bars. The TT frame, wheels etc only give you a very small aero advantage over ordinary road kit.

The frame is one of the smaller gains if you think in terms of the frame being aero (i.e. if you assume same position etc, only thing changing being the frame), however, a well fitting aero frame will put you in a better (where better is more aero AND powerful, with greater stability and control) position than a road bike with clip on aero bars, so you will be faster. Position is absolutely paramount for going fast and the time differences small changes to position make can be huge.

The other things you mention are also large gains, an aero helmet is worth a lot of time as is a skinsuit vs a normal shorts and jersey combo. I would argue contrary to wheels only being a small advantage though, a good set of aero wheels are certainly not marginal gains.

 

[User482]

The frame is one of the smaller gains if you think in terms of the frame being aero (i.e. if you assume same position etc, only thing changing being the frame), however, a well fitting aero frame will put you in a better (where better is more aero AND powerful, with greater stability and control) position than a road bike with clip on aero bars, so you will be faster. Position is absolutely paramount for going fast and the time differences small changes to position make can be huge.

The other things you mention are also large gains, an aero helmet is worth a lot of time as is a skinsuit vs a normal shorts and jersey combo. I would argue contrary to wheels only being a small advantage though, a good set of aero wheels are certainly not marginal gains.

I've never done a road TT, I'm only going on what I read. They calculated the percentage gains by changing each item, and wheels/ frame were much lower than some of the cheaper changes. I wish I could find it!

 

[VamP]

I've never done a road TT, I'm only going on what I read. They calculated the percentage gains by changing each item, and wheels/ frame were much lower than some of the cheaper changes. I wish I could find it!

You only need to look at how much time Froome put into Contador on the last 12 km of Stage 17 of this year's TDF for a practical demonstration of the difference a TT bike position makes over road bike with clip ons.

 

[Rob3rt]

There are quite a few articles like that. Some good, some not so good. I recall one of them doing some rather odd wheel comparisons.

My experience of riding a disc and trispoke vs road wheels (on the same bike, on the same courses, obviously weather varying) is that the disc made a substantial difference to my times when paired with a standard road front wheel, the trispoke, added on later again gave a notable advantage, however in ultimate terms, not as much as the disc, since I was now travelling faster so any W savings from the trispoke would indeed result in a smaller relative time saving. I haven't tried running the trispoke up front and a road wheel in the back.

 

[User482]

You only need to look at how much time Froome put into Contador on the last 12 km of Stage 17 of this year's TDF for a practical demonstration of the difference a TT bike position makes over road bike with clip ons.

There are too many variables in a road race to draw any definitive conclusions.

 

[VamP]

There are too many variables in a road race to draw any definitive conclusions.

Such as?

 

[User482]

Such as?

It's very difficult to say how much was down to the rider and how much was down to the bike. Clearly, a TT bike position does make a difference - we can be sure that Sky have done extensive wind tunnel testing - but the point I was making was that bigger gains are achieved through other measures.

 

[VamP]

It's very difficult to say how much was down to the rider and how much was down to the bike. Clearly, a TT bike position does make a difference - we can be sure that Sky have done extensive wind tunnel testing - but the point I was making was that bigger gains are achieved through other measures.

Froome was nearly 30 seconds down at the 2nd timing point, and 9 seconds up at the finish. The last 12 km were a steady descent, for which Froome changed to his TT bike and Contador stayed on his road bike with clip ons. In every other regard (skinsuits, helmets, wheels etc.) their equipment was identical. It is widely considered that Saxo made a tactical error in not changing to a TT bike for the last 12 km. It's as clear a demonstration of the difference in position as I can think of.

The point I and Rob3rt are making, which you are steadfastly ignoring, is that there is a significant difference in the position that you can adopt on a TT bike, versus a road bike with clip ons. This is what makes the most difference in aero terms. The actual aero profiling of the bike itself is of marginal significance.

 

[Rob3rt]

It's very difficult to say how much was down to the rider and how much was down to the bike. Clearly, a TT bike position does make a difference - we can be sure that Sky have done extensive wind tunnel testing - but the point I was making was that bigger gains are achieved through other measures.

Chris Froome has only recently been into the wind tunnel for the 1st time, apparently. No idea about their other riders.

 

[User482]

Froome was nearly 30 seconds down at the 2nd timing point, and 9 seconds up at the finish. The last 12 km were a steady descent, for which Froome changed to his TT bike and Contador stayed on his road bike with clip ons. In every other regard (skinsuits, helmets, wheels etc.) their equipment was identical. It is widely considered that Saxo made a tactical error in not changing to a TT bike for the last 12 km. It's as clear a demonstration of the difference in position as I can think of.

The point I and Rob3rt are making, which you are steadfastly ignoring, is that there is a significant difference in the position that you can adopt on a TT bike, versus a road bike with clip ons. This is what makes the most difference in aero terms. The actual aero profiling of the bike itself is of marginal significance.

Correlation is not causation.

As for your second point:

Clearly, a TT bike position does make a difference

Perhaps you would do me the courtesy of reading my posts rather than attributing an opinion to me that I do not hold.

 

[User482]

Chris Froome has only recently been into the wind tunnel for the 1st time, apparently. No idea about their other riders.

Really? I find that interesting, given their fame for attention to detail, and the marginal gains stuff.

I found the article here: http://cyclingtips.com.au/2010/04/biggest-bang-for-your-buck-in-time-trial-equipment/

I guess what's heartening - if the article is correct - is that the amateur can make significant gains without spending a fortune.

 

[VamP]

Correlation is not causation.

As for your second point:



Perhaps you would do me the courtesy of reading my posts rather than attributing an opinion to me that I do not hold.

You really a cantankerous type aren't you? Welcome to my thread