Giro TT Bike/ Wheel Selection

I kind of regret not spending some drops on the Specialized Shiv S-Works before this race, ehem Ride.

I went with the Specialized Shiv Disc and Lightweight Wheels.

I gave it a good go with a great warmup, but failed to crack 20 minutes by a slim enough margin that makes me think. There were a lot of different setups from all the riders.

Good news is that it appears as though this course at least will support any TT frame in a race so there’s reason to spend some drops should I wish to pursue better times on this course.

There are certainly a lot of different ways to approach this course as far as bike setup and when you lay the power goes. I’ve never been much of a short distance rider but I’ll give this one another go every once in a while, it was fun and good for my endurance legs.

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You cant whole heartedly recommend something without doing it yourself, so I picked up the Specialized Shiv S-Works in the interest of karma. I’m sure it’s quicker uphill. Can I be quicker is a whole nuther question.


Anyone done this TT more than once to compare climbing road setup vs TT setup using the same approach power wise? Curious as to which setup is faster.

Without a doubt, a steady pace from start to finish is NOT the way to go. How to say… Same rider, same weight, same bike, same avg power but ridden differently:

  • steady pace from start to finish
  • sub avg pace for 6km, followed by above avg pace for 2km climb

The latter will be faster for sure.

I’ve done it twice, but I can’t say I held the same power.

First attempt

Canyon Aeroad with Lightweight wheels

Best 20 min power: 259W
Weighted average: 260W

Time: 20:16

Second attempt

Zwift TT bike with Zipp 808/Super 9 disc

Best 20 min power: 264W
Weighted average: 253W

Time: 19:39

So, power was overall fairly similar. I probably rode a bit harder the second time, as I knew what to expect from the first one.

In terms of Strava segments (which don’t necessarily match in-game results), on the full event I was 35 seconds faster:

I was 28 seconds faster on the flat section - mostly TT bike I guess, although the power was a bit higher too.

I was 10 seconds faster on the climb with the TT bike.

But as you can see, I did do more power again.

In terms of power compared to FTP, I ended the second attempt with Zwift reporting an FTP increase to 251W (reported 248W at the end of the first attempt, up from 244W in my ramp test a few weeks ago). So I actually did the flat section at about FTP (248W) and the climb significantly over FTP (283W).

If I get another opportunity, I might try the Tron bike and riding a bit more below FTP on the flatter part.


Ideally, you go sub-threshold for the first 6km then hammer over threshold for the last 2km. How much under for the first 6km, I don’t know. H3ll, it’s so short that going threshold for the first 6km might be okay and then full gas for the remainder. I guess it depends on how one tolerates riding above threshold which will vary for two riders of the same FTP :thinking: In any case, that steep 2km climb is where you will make or lose time.

I did an easy recon ride yesterday. I thought the course was going to run the duration of the Giro or at least the whole first week, but it looks like tomorrow is the last chance. Hopefully, I have time to give it a real push.

Regarding Giro TT pacing (not bike/wheel selection :grinning:), Shane Miller has some thoughts:

I’m beginning to think Bike/ Wheel selection isn’t much of a factor for this course. I did it 3 times, 3 different frames, all with lightweights. I was progressively better at doing the first 6km in the yellow and finishing the last 2k in the red, but I also put out a few less watts each attempt. So I’m calling it a wash at least with the lightweight wheels as a control.

1st attempt
Specialized Shiv Disc and Lightweight Wheels
20:27 avg power 256W

2nd attempt
Specialized Shiv S-Works and Lightweight Wheels
20:23 avg power 254W

3rd attempt
Trek Emonda and Lightweight Wheels
20:28 avg power 251W

What really burned me was the ride clock at the finish. I thought I had my sub 20 minute run in, only to find out seconds later looking at the results that I missed it by over 20 seconds.

You can see in the pic I had 8 seconds to cross the finish line, or so I thought. Same thing happened on my third attempt but I knew better. I must have forgotten that since Saturday’s first attempt.

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My first try was ~300watt on the flat and ~300watt uphill, time was 18m31sec. (305watt total average)
Second try was ~270watt on the flat and ~340 watt uphill, time was 17m45sec (309 watt total average)

So pretty much the same average on both rides but a very different time.

100% how GPLama said on his YouTube channel

Both rides with the Cervelo P5

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What’s the reason for this - often happens in TOW events etc too, is there some pre-start line riding that counts as time on the event? Also was burying it for sub-20, just missed that but then up pops 20:39 in the event page and also Zwiftpower.

Gave it a push before lunch.

I didn’t look at the clock but I think something is off. Maybe Zwift is including the lead-in time in the final results?

Official Zwift result: 17:15 @ 322W
Strava Segment: 16:50 @ 323W

Bike: Specialized Shiv S-Workds TT w/808 Disc Combo
Helmet: Bell Javelin (no advantage, but why not? it’s a TT! :smile:)

I rode the flat reserved. Then pushed on the climb. Dropped my chain twice around 7.5km, costing a few seconds for sure. Can’t wait till the course is available for an event to give it
another push.


Zwift results and therefore ZwiftPower show the event time; which starts when the flag drops. That is the same with any event. The on-screen timer starts at the start/lap banner and should match the Bologna TT (Zwift Insider verified) time. You may notice on other courses this timer often starts just outside the Pens indicated by a mark on the road.

London for example.


Makes sense, sort of. :+1:

I’m happy with Zwift and ZwiftPower for extended data, and have no plans to add Strava.

It looks like the in ride clock can be trusted for the route by looking at all the data provided above, I’m happy with that.

To reference my OP, no new bike was ever required, lol. I need to spend my cache of drops on something so no regrets there, I like new kit.