2019 Giro d'Italia, Stage 1: Bologna - San Luca ITT 8km

[King Boonen]

I'm wondering if the smaller guys like Yates might need to switch for the psychological boost of not trying to drag the TT bike up those ramps?

 

[LaFlorecita]

In my view:
Lighter guys like Yates and MAL --> switch to limit the losses on the flat part and maximize gains on the hill
Bigger, diesel guys like Big Tam --> ride a TT bike (with the lightest possible setup) all the way

Like Escarabajo said, Contador sometimes used a road bike with TT bars. I'm still not sure if that was smart or not, I guess it's really hard to figure out what is the correct decision. For this particular TT I'm thinking the distance for both the flat and hilly part is just at that point where switching enters the discussion, but I'm guessing it won't make a big difference.

 

[Red Rick]

Re:

I guess it's either bike change or no disc wheel?
Can't imagine other options, though I'm no big expert.

Pretty sure no bike changes cause there's no way a TT bike alone loses like 15 seconds to a road bike on a 6 minute climb

 

[Climbing]

Re:

In my view:
Lighter guys like Yates and MAL --> switch to limit the losses on the flat part and maximize gains on the hill
Bigger, diesel guys like Big Tam --> ride a TT bike (with the lightest possible setup) all the way

Like Escarabajo said, Contador sometimes used a road bike with TT bars. I'm still not sure if that was smart or not, I guess it's really hard to figure out what is the correct decision. For this particular TT I'm thinking the distance for both the flat and hilly part is just at that point where switching enters the discussion, but I'm guessing it won't make a big difference.

Considering that he was flying back then, probably he would have been alright with a Graziella and TT handlebars.

 

[Climbing]

Re: Re:

I guess it's either bike change or no disc wheel?
Can't imagine other options, though I'm no big expert.

Pretty sure no bike changes cause there's no way a TT bike alone loses like 15 seconds to a road bike on a 6 minute climb

Yeah, but I meant using a TT bike with no disc wheel possibly, that would make a difference uphill, I guess.

 

[Rollthedice]

"Thanks also to the tests in the Gorizia wind tunnel, a new handlebar is ready in the style of that of Campenaerts, fresh record holder of the hour. It is lighter and more aerodynamic, created after simulations in 3D on Nibali's body shape and in the version to be used uphill (like San Luca, the first day) even 6 cm higher for greater performance when the Shark will stand up on the pedals."

I guess it'll be a TT bike for Nibali.

 

[Climbing]

But I've heard Nibbles himself talking about a possible bike change, not sure it's already a definite answer.
Other riders as well weren't certain, unless somebody already tested it on course.

 

[Escarabajo]

I wonder about the handle bars. Why not make one low in the middle and high on the sides!
That would look ugly.

 

[Salvarani]

Yeah, there is definitely gonna be some time gaps between the favorites. It wont tell much about the outcome of this race though. If you within 20-30 seconds behind it will be all good for a lot of them I think.

Dumo and Roglic to gain some time. It will be pretty close between them I think. Are you better off not taking the jersey?

 

[HelloDolly]

I think on such a short course a bike change is fraught with risk

If the course were longer then maybe...Remember Bergen but that didnt always workout well as far as I remember

For most GC men a road bike with bars seems sensible.Most advantage they can get is on the climb and even on road bikes their flat section performance wont be too much in jeopardy

The one with the biggest dilemma will be Dumoulin who could one would surmise be stronger on the flat than Roglic & Yates. Can he push home that advantage and include a bike change ? Or will he lose it on a road bike with bars

 

[Sestriere]

Re: Re:

I guess it's either bike change or no disc wheel?
Can't imagine other options, though I'm no big expert.

Pretty sure no bike changes cause there's no way a TT bike alone loses like 15 seconds to a road bike on a 6 minute climb

Assuming a weight of a road bike being 6.8 kg and that of a TT bike being 8 kg (this refers to Richie Porte's Trek measured by GCN to 7.8 kg earlier this year; taller riders may have to accept bigger weight penalties so I went with 8 kg) I made some calculations for the climb. In this first attempt I neglected any friction or aerodynamic drag, which at an average speed of about around 22 km/h is questionable. However, I don't have any information about cw-values for road bikes, TT bikes or any of the positions that a rider might sit (or not) on his bike on the climb. Same goes for frontal area, which would also be required to include aerodynamic drag. The following results thus only account for potential energy.
Further assumptions I made:
- avg. power: 450 W
- rider weight: 70 kg (assuming a constant effort of about 12 - 13 min this accounts for 6.4 W/kg, you may debate about that as well)
- elevation gain: 204 m
- avg. gradient: 9.7 %

This yields
- Road bike: 341.5 s or 5.69 min
- TT bike: 346.9 s or 5.78 min
=> difference of 5.4 s

Assuming a rider more of Simon Yates' physique
- avg. power: 366 W to achieve same power/weight
- rider weight: 57 kg

One obtains
- Road bike: 348.9 s or 5.81 min
- TT bike: 355.4 s or 5.92 min
=> difference: 6.5 s


Again, this is solely an energetic consideration, as there are too many unknown (for me) to factor in aerodynamic drag properly.
However, I think we can agree that you are likely going to lose more time during the 5.9 km of flat with a road bike compared to a TT bike than the calculated ~ 6 s. Maybe an inbetween solution like fitting a road bike with disc wheels and aero bars or a TT bike without rear disc as seen during the mountain TT of the 2016 TDF are viable? Ultimately, it will probably come down as to how comfortable the riders feel on a 16 % ramp with their TT bikes.

 

[Climbing]

I meant using a TT bike without disc wheel, I think using a road bike isn't really a viable option, would lose too much on the flat (unless is super technical, which isn't the case apart some passage).

 

[Red Rick]

Road bike with ITT bars is really only something for major MTT with like 5km of flat.

Really disc wheel or not should literally be the ONLY consideration.

 

[Cookster15]

I don't have a clue but I am sure all the GC riders and teams have been preparing and testing in anticipation of this stage. Will be interesting to see what pans out. But I think Dumo will do well, slightly ahead of Roglic.

On Setriere's calculations these assume the same power for both TT and road bike. In reality on a steep short partially anaerobic climb like this the rider will be able to maintain significantly more watts on a proper road bike.

A road bike puts the rider in a more optimal upright position that a TT bike optimised for aero position. So the calculations are seconds lost on the flat and bike change less seconds gained for lower weight and slightly higher power on the climb with a road bike.

 

[Valv.Piti]

Re:

Could easily have 30s+ gaps here already

0% chance Dumoulin and Roglic don't get top 2 without crashing

I could easily Yates see finish second ahead of Dumoulin on this kind of time trial.

 

[Red Rick]

Re: Re:

Could easily have 30s+ gaps here already

0% chance Dumoulin and Roglic don't get top 2 without crashing

I could easily Yates see finish second ahead of Dumoulin on this kind of time trial.

I'll have what you're smoking.

 

[Sestriere]

Re:

I don't have a clue but I am sure all the GC riders and teams have been preparing and testing in anticipation of this stage. Will be interesting to see what pans out. But I think Dumo will do well, slightly ahead of Roglic.

On Setriere's calculations these assume the same power for both TT and road bike. In reality on a steep short partially anaerobic climb like this the rider will be able to maintain significantly more watts on a proper road bike.

A road bike puts the rider in a more optimal upright position that a TT bike optimised for aero position. So the calculations are seconds lost on the flat and bike change less seconds gained for lower weight and slightly higher power on the climb with a road bike.

How would you quantify this "significant" difference in power? Would be no problem for me to implement it..
As, I wrote, for many it will probably come down to personal preference.

Regarding the discussions about road bike with aerobars, I seem to recall that Bauke Mollema rode a road bike with disc wheel and TT bars during the 2016 TDF TT. It was put on scales by GCN and weighed 6.8 kg. Don't know how this compares in weight and aerodynamics to a TT bike without rear disc.

 

[sir fly]

Aru said that in this tt time can be lost just like that.
The hairpinned approach to the ascent favours a bike change... far enough from it to get into the rhythm.

 

[Kwibus]

Will Campenaerts try to contest this and does he have a chance to reach top10?

 

[Red Rick]

Will Campenaerts try to contest this and does he have a chance to reach top10?

Top 10, yes.

Not the win quite obviously.

 

[sir fly]

The turn to San Luca.
Not sure about disc wheel at all... to put it that way.

 

[Laplaz]

There is a chance of rain around 8 pm. So the top-riders might start early...

 

[Lequack]

Re:

The turn to San Luca.
Not sure about disc wheel at all... to put it that way.

Now I remember. That's the same climb they use in Giro dell'Emilia. I watched it last year and remember Kirby explaining about the wall on the left of the road.

 

[King Boonen]

Re: Re:

The turn to San Luca.
Not sure about disc wheel at all... to put it that way.

Now I remember. That's the same climb they use in Giro dell'Emilia. I watched it last year and remember Kirby explaining about the wall on the left of the road.

It's the longest colonnade in the world I think, very impressive site and a good choice for the prologue.

 

[Robert5091]

Re:

There is a chance of rain around 8 pm. So the top-riders might start early...

From what I've seen Sunday's forecast is for showers too.