What to look for in a bike for a TT newbie?

[PortableDave]

Hi,

Looking at doing some ITT's sooner rather than later and well .. I need a bike, currently I only have flat bar road bike which obviously isn't suitable. I am interested in advice on minimum spec component wise, ie. should I look at nothing less than a 105 groupset as some people have told me or is Tiagra/Sora level components okay for a beginner? I am looking at spending $1600 or less, at that price am I better off getting a decent second hand bike over something like a Giant Defy new? Any help is appreciated!

[tripstobaltimore]

Look for second hand, you can get a lot for $1600. Check www.transitions.org.au tritrade section, as a lot of bikes come up there. Also your states triathlon body may have a for sale section on their website.

[PortableDave]

Thanks for that! I will just have to be patient, seems to be far fewer second hand bikes in the frame size I need (58 - 60).

[tripstobaltimore]

Yeah just keep an eye out and be patient.

[MiG]

In my opinion the spec of the drivetrain is the least important part. Look for a front end low enough to put clip on aerobars on ($50) in a low position. Funnily enough your flat bar with aerobars could have less drag than a drop bar, since the drops are extra unnecessary tube length.
$50 aerobars slammed as low as they'll go on my frame have given me a ~2 km/h speed and comfort boost over low drops, so don't fuss about irrelevant stuff like fancy pants derailers and brifters, they just look pretty, weigh a bit less and last longer. If you were doing criterium racing or a very large volume of training those bits would be more important. Your body's drag is the biggest obstacle to TT speed.
Another odd thing is that a spindly steel frame could have less drag than a basic "aero" aluminium frame made of large slightly ovalised tubing. Shape is important but so is cross section.

[Parrott]

Another odd thing is that a spindly steel frame could have less drag than a basic "aero" aluminium frame made of large slightly ovalised tubing. Shape is important but so is cross section.

The spindly steel frame is probably going to flex like buggery though and any negligable aero benefit is going to be more than lost by the flex?

[MiG]

Can you explain how flex in an elastic medium become a loss? It just feels unpleasant. It worked for generations of cyclists, including sprinters, so I think you'll be fine while spinning at constant power in a TT (= low torque). Plenty of weight weenies are putting up with wet noodle forks and frames.

[gclark8]

I have a TT-TRi bike for sale: http://www.bicycles.net.au/forums/viewt ... 25&t=16550

[Parrott]

Can you explain how flex in an elastic medium become a loss? It just feels unpleasant. It worked for generations of cyclists, including sprinters, so I think you'll be fine while spinning at constant power in a TT (= low torque). Plenty of weight weenies are putting up with wet noodle forks and frames.

No I can't really but I'll try anyway My P2C when placed on the magtrainer is heaps stiffer than my alloy/carbon framed Azzurri. If I look down at the BB on the Azzurri I can see it moving from side to side with the pedal stroke where the cervelo doesn't move. I can run a higher cadence for the same resistance on the cervelo because more of the energy put into the pedals is transferred to the rear wheel, not wasted displacing the frame from side to side.

As far as flex working for generations of cyclists, they used what they could get their hands on. Now that they are available, they are after stiffer frames. Don't see too many spindly tt frames being developed.

[MiG]

No I can't really but I'll try anyway My P2C when placed on the magtrainer is heaps stiffer than my alloy/carbon framed Azzurri. If I look down at the BB on the Azzurri I can see it moving from side to side with the pedal stroke where the cervelo doesn't move. I can run a higher cadence for the same resistance on the cervelo because more of the energy put into the pedals is transferred to the rear wheel, not wasted displacing the frame from side to side.

As far as flex working for generations of cyclists, they used what they could get their hands on. Now that they are available, they are after stiffer frames. Don't see too many spindly tt frames being developed.

A swinging pendulum moves from side to side, the motion isn't a loss. Now that's by no means proof that frame flex isn't detrimental, but it does prove that there's more to consider than just displacement.
These days nothing except carbon is developed because it's desirable. How many people are gonna buy a new bike that looks like it's from 1970?
Have you seen Graham Obree's latest hour record bike? It's not proof of anything, after all the hour attempt has been cancelled, but you might find it at odds with current fashion.
http://www.bikeradar.com/news/article/g ... gain-21712

[Parrott]

A swinging pendulum moves from side to side, the motion isn't a loss. Now that's by no means proof that frame flex isn't detrimental, but it does prove that there's more to consider than just displacement.
These days nothing except carbon is developed because it's desirable. How many people are gonna buy a new bike that looks like it's from 1970?
Have you seen Graham Obree's latest hour record bike? It's not proof of anything, after all the hour attempt has been cancelled, but you might find it at odds with current fashion.
http://www.bikeradar.com/news/article/g ... gain-21712

No it's not a loss but it is energy that is not transferred to the rear wheel. Probably not a big difference percentage wise and it's probably not going to make a difference for someone just starting out I guess.

Yep that bike of Graeme O'brees does look spindly compared to current bikes, pretty hard to make a custom carbon bike yourself though. Nice low position on the bike, pretty flexible, especially for a 43 year old