Help me to choose features for a fast TT/Tri frame (weight vs aero)

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alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Hi WW's...

I'm trying to decide what kind of TT/Triathon style frame to try. It's my first time getting a second bike sort of speak. I got a climber with deep wheels at 5.9kg already and managed to take a few Strava KOM's around here where I live.

It's tube profiles have rounded corners but it's more or less a box + round shape everywhere. Not really a wing shape. No rear wheel mating with the frame and the brake calipers are all in the wind.

(My longer routes that I'd like this TT bike for are around 150km and have a total climb at around 1000m. Climbing is the price to pay for going the scenic route. Of course I'd like it to be fast aswell. I'm trying to get the fastest time on some flat road strava segments.)

I'm looking at chinese frames because I've had a good experience with them and because I'm not a rich guy. There are many kinds to choose from.

Obviously a TT/Triathlon bike is going to be heavier but how important is saving weight for the sake of some aero features like:

1. Brake calipers mounted inside the fork.
2. Brake calipers mounted behind the fork with the cable going past the outside of the headtube.
3. Brake calipers mounted conventionally like on cervelo's most TT bikes.
4. Diamond vs wing shaped (naca) tube profiles?
5. Front wheel going into the down tube arched cutout?
6. Huge rear wheel cutout in the frame going from seat tube to bb vs a smaller cutout starting at half the seat tube.
7. Rear brake under the bike open to the elements as opposed to covered by an intricate streamlined frame enclosure.
8. Inner routed cables around the cockpit.
9. Integrated stem+basebar+tt-bars (a lot of weight saved)
10. Stem that is perfectly flush with the top tube.

I'd like to show two examples of a lightweight tt bike and a heavy one. Difference is maybe up towards a kilogram including the bars and brakes.

Heavy bike with all the features listed above:
Image
http://www.miraclebikes.com/products/path099/path0151/2017besttriathlonbikesnewtimetrialbikesIronmanbicy26195528/

Light bike with integrated bars+stem, exposed cables, partially exposed brakes.
Image
Image
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Image

Medium light without integrated bars+stem.
Image

/a

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Pokerface07
Posts: 213
Joined: Wed Jun 06, 2012 11:43 pm

by Pokerface07

First off, get a bike that fits you.

Secondly, aero trumps weight for TT bikes. Even on a hilly course (unless it's all uphill!).



Your first bike example looks to be more aero, but there is really no way to know for sure without actually testing it.

Ultimately, it's your position on the bike that is going to make it go faster, not whether or not it has exposed cables/brakes/etc.
Twitter: @FormerTTchamp https://twitter.com/FormerTTchamp

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