PatrickGSR94

Please forgive what is probably a n00b question, but this is my first time being interested in following a professional bike race - the 2012 TdF. I was just watching the ITT's from Saturday on YouTube and noticed how much different those bikes are as compared to the normal stages. Looks like a shorter wheel base, different bars, the aero bars, aero helmets and everything. But then in the stages they all wear normal-style vented helmets, normal-looking road bikes with normal drop bars. Why the difference? Why not time trial on the same type of bike as on the stages?

Mithrandir

Time trial bikes are faster than road bikes because they are more aerodynamic, but it comes at a cost of comfort. Time trial stages are usually much shorter than road race stages, so the comfort isn't usually missed there.

Additionally, tt bikes in the aerobar position are a lot less maneuverable, so if people rode those on the group stages they'd cause a lot more crashes.

PatrickGSR94

I see, makes sense for why the TT bikes aren't used on the stages. But why not just use the same road bikes for TT's? Sure they're not quite as fast, but why does it matter when everyone uses the same type of bike?

Bacciagalupe

The TT bikes offer significant aero advantages, and TT's are won or lost by seconds. As long as it's allowed, using a road bike when everyone else is using a TT bike is giving up time.

Pros will occasionally use road bikes for a TT stage, but only if the roads are wet or the course is too technical for that rider.

Riders used to use the same bikes for TT's as for road stages. For whatever reason, the UCI allowed the use of aero bars, and after that TT-specific bikes, in the TT stages. They didn't have to, so presumably they figured there would be a benefit to the sport to allowing different bikes.

slims_s

Road bikes are also seen on uphill TTs, sometimes with clip-on aero bars, too.

PatrickGSR94

I see, I figured it was mandated that everyone use the same type of bike in TT's, and the same type in the stages, and I just wondered why it was different. If they have a choice in TT's then I see why everyone would choose to go with the faster TT bike, obviously.

HardyWeinberg

And seconds gained on a 6 km TT count the same as seconds gained on a 200km road stage even though they are much more easily gained (and lost) so they can be really important seconds.

merlinextraligh

Comfort has nothing to do with it. If it were faster and legal to ride a TT bike in a road stage, people would do it.

The answer is that TT bikes are not legal for mass start racing. If you ever watch a bunch of triathletes riding togehter on their aero bars it's easy to see why they're not.

fietsbob

Used to be so.. for time trial the bike got an overnight clean and lube more lightly.
maybe a small gearing change, course specific, but not, otherwise..

aerospace trained engineers got in on the search for the edges
of the rule book, that they pushed against, and got changed

mothon

I also think a big part of it is marketing for bike sales.

spinerguy

or sometimes also used by domestiques that don't really make any difference in the general classification.

chasm54

What? If you don't think time-triallists are faster on TT bikes, I'm afraid you're very much mistaken.

telebianchi

I am guessing the first post refers to why the rules allow for the different bikes, not why the riders use them.