Bologna TT Showdown: TT Bike vs. Road Bike Post-Upgrades

First introduced in May 2019, the Bologna Time Trial Lap course is short but brutal. It’s split into:

• 6.0 km of flat terrain through the historic streets
• 2.0 km climb averaging 9.7%, up to the Sanctuary of San Luca

This makes it close to a 50/50 split of flat and climbing for many Zwifters.

Why Retest?

Since its debut, Bologna TT has been well-studied. But with recent Zwift bike upgrades, earlier conclusions are up for debate. A discussion on the Kaboom Discord prompted this investigation after discrepancies appeared in the ZwifterBikes.web.app.

One Kaboom rider, Eric Brown, found that the app showed a 40-second advantage for the road bikes over TT bikes, which seemed suspicious. Oddly the same rider stats resulted in a different outcome on ZwifterBikes.web.app for myself, with the best TT bike being 10 seconds faster than the best road bike. I’d already established that the TT bike with disk wheels was the fastest setup for my A cat team in previous years’ testing, with a bike swap being a marginal gain with high risk. But I had to know – had the bike upgrade changes shaken things up? This required a test in Zwift to verify.

Organizing the Test

For those that don’t know, Bologna is an event-only world, making testing a little more tricky for those who live in the Eastern states of Australia like myself. It seems that every time I check zwifthacks.com/app/events for events on this course, they are on at “stupid O’clock” in the early morning hours. Luckily, Zwift has a “feature” that accommodates us: I could sign up for an event and then leave my avatar sitting on the side of the road whilst I go to bed and dream about riding away from Pogacar on the queen stage of the 2025 TDF (or the draft gauge being displayed natively in Zwift) and Zwift will automatically place the rider in the event.

I grabbed my morning coffee and greeted my Zwift avatar over a bowl of cold milk and Weetbix drizzled with honey. Hitting the “leave event” icon, I then logged into Zwift on my phone to trigger my original signed-in account in Bologna to be signed out and in a pseudo “offline” mode to ensure I didn’t contaminate my Zwift stats like XP, drops, bike upgrades etc.

WARNING: Despite the notice bar at the top stating stats won’t be counted, your fitness signature is still affected in this mode, so be careful with power durations if you don’t want to impact category rankings.

Test Setup

5 scenarios were tested using different rider profiles:

• 75 kg @ 173 cm @ 350 watts and then a split power 330w on flat, 370w on climb
• 50 kg @ 165 cm @ 5 W/kg and 3 W/kg- 90 kg @ 173 cm @ 250 watts (2.8 W/kg)

Bikes Used

• Road: Level 4 S-Works Tarmac SL8 + Enve SES 7.8 wheels
• TT: Level 5 Cadex + Enve SES 7.8 (Zipp 858/Super9 tested as well in first round in video). Zwift’s Ghost feature was used to compare previous runs and give a good visual guide.

Watch the Video

Results Snapshot

“The slower you go, the more time you spend climbing. That makes the road bike more advantageous.” – from the video

Interpretation

• At high power outputs, the TT bike wins thanks to its flat-section dominance.
• At low power outputs, the road bike can outperform due to increasing the ratio of time spent on the climb compared to the flat.
• The differences are small (~9 seconds), and pacing is still a very important factor. As Shane Miller says, “Go hardest when you’re going slowest.”

While TT bikes still hold an edge for strong riders, the Bologna TT course becomes road bike-friendly for less powerful riders. I would estimate that 3.2 W/kg is probably the tipping point where the TT bike starts to see an advantage for most rider sizes. Whilst I did get largely different finish times compared to zwifterbikes.web.app, the predicted time difference between the bikes were within a few seconds. Therefore, I feel that the bike recommendations may well be accurate enough to trust. They seem to line up well with the equipment tests published on Zwift Insider and my previous testing.

Recommendations

• High wattage (3.2 W/kg and above) -> Stick with your TT rig.
• Low power riders -> Consider a lightweight road setup, especially if you spend a long time on the hill.
• Willing to risk it for a biscuit? Try a bike swap: start on a TT bike for the flat and switch to a roadbike after the right hand turn starting the climb. There is potential to gain a large number of seconds for those in the lower categories who are well versed in fast bike swaps.

Your Thoughts

What’s your go-to Bologna TT race rig? Share your thoughts below!