Zwift Racing League Week 4 Guide: Greater London 8 TTT

September 25, 2024

LAST UPDATED October 30, 2024

The fourth race of Zwift Racing League 2024/25 Round 1 happens Tuesday, October 1. It’s the second team time trial of this round, and our first with a real climb.

The race course: 1 lap of London’s Greater London 8 route, which includes the Box Hill KOM.

The climb up Box Hill makes this an especially interesting TTT in terms of pacing and team selection. Let’s dive into route details, bike choice, and all things TTT…

Looking at the Route: Greater London 8

London’s Greater London 8 route is 24.4km long, with 280m of elevation gain. Its most obvious feature is, of course, the Box Hill KOM:

Here’s a modified version of Sherpa Dave’s notes from when this route was raced as a Thursday TTT back in 2021:

As you go through the start/finish gate, you have a 500m incline at 2%.
Descend for 1km at 2% into the tunnels, then come back up the other side at a shallow 1.2%.
At the 3.6km mark, you will turn sharp right onto Northumberland. 300m at 4.5% ending in a left turn.
2-bump descent toward Parliament
Mostly flat for 5.5km until you start the descent to Hyde Park corner. Pick up speed as you descend into the tunnels.
Piccadilly ascent starts at 11km. It stretches 900 meters and averages 2% – but it is broken into two 3% sections with a short flat in the middle. You will see the end of the climb approaching because the road turns a sharp right.
3.9 km of flat or descending until you emerge in Surrey and begin the main climb of the ride – Box Hill… but don’t forget the short, sharp drop into the Underground at 15km.
Box Hill starts at 16km. A lot of the climb is draftable, but as it pitches over 5% and speeds drop the draft effect will lessen. Ideally stay together to benefit where you can. The climb breaks into three sections:
- The first 800m (to the first sharp U-turn) is slightly steeper, getting up to 7.5%, averaging 5.5%
- The last 2/3s (1.9km) is a steady gradient averaging 4.8%
- The last 300m of the timed section is a slight downhill
Box Hill Kicker: 150m peaking at over 10% – nobody can help you here… push hard and stay with your teammates.
Fox Hill Descent is a beautiful 2.4km (less beautiful if you’re going the other direction). The trick to this descent is to accelerate over the kicker and get up to speed as fast as you can.
At 22.8km you’ll hit the ramp out of the Underground. Go hard to keep your speed high on the ramp, then keep the power high to get back up to speed for the flat finish.

Bike Frame + Wheel Choice

You may think that a lighter wheelset is the way to go because of the big Box Hill KOM on this course, but that’s definitely not the case. In a TT the strategy is simple: pick the wheelset and frame that gives you the fastest overall time.

If you look at our wheel performance data and do some simple math, you can draw a few important conclusions:

The lightest wheels (Lightweight Meilensteins or Roval Alpinist) are 23 seconds faster up the entire Alpe du Zwift climb vs the fastest wheels (DT Swiss disc). We can divide that difference by 7 to approximate what sort of difference the wheels would make on the shorter Box Hill KOM: 3.3 seconds.
A good all-arounder wheelset, the ENVE 7.8s, are 14s faster up the Alpe vs the DT Swiss disc. That’s a 2-second advantage on Box Hill.
But the DT Swiss Disc is much faster on flats and descents. They will be approximately 10.5s faster on the rest of the course compared to the ENVE 7.8s (so a net advantage of 8.5s), and a whopping 32 seconds faster than the “pure climber” Lightweights and Rovals (net advantage: 28.7s)

Frame performance works out similarly. To put it simply: aero is everything. Switching to a lighter frame, even the zippy and light Felt IA 2.0 or Scott Plasma RC Ultimate frames, gives you a net disadvantage vs the more aero CADEX Tri and Canyon Speedmax Disc frames.

So bike choice is easy: grab your most aero TT setup! The CADEX Tri is the fastest frame in game by a solid margin, and the DT Swiss disc wheels are the fastest wheels. If you don’t have access to that setup (level 40+) then see this post to determine the fastest TT setup available at your level.

Whatever you do, do not use a road frame. Because just like in real life, even a “slow” TT frame is much more aero than a road frame.

Route Recon Videos and Resources

Lots of recon events are scheduled on upcoming ZRL routes, led by various teams. See upcoming ZRL recons for this race at zwift.com/events/tag/zrlrecon.

In The Drops

See Greater London 8 course notes >

John Rice

TTTips

Team Time Trialing on Zwift is a challenging mixture of physical strength, proper pacing, and Zwift minutiae like picking a fast bike and understanding drafting in a TTT context.

Flatter courses like this week give valuable seconds to teams who can keep their speeds high over false flats. If you typically run your trainer difficulty setting pretty low, we advise you to raise your Trainer Difficulty high enough that you can feel slight incline changes and automatically increase power to keep your speeds high.

Climbs like this week’s Box Hill KOM also present an opportunity to gain or lose lots of time over a short distance. You will want a target pace and attack plan for this section to ensure your team is climbing as fast as possible. You may also need to make decisions about dropping riders on this climb, because waiting for them may cost you more time than they can pull back on the descent and flats to follow. If your team includes a slow climber with decent pure watts, it may make sense for them to take a suicide pull leading into Box Hill to give the team a final boost before dropping off.

Your goal in a ZRL TTT is to get four riders across the line in the shortest time possible. That means every team’s pace plan will differ based on the abilities of each rider. We highly recommend having an experienced DS on Discord directing your team, especially if your team contains some inexperienced TTT riders.

If you really want to go down the TTT rabbit hole, check out Paul Fitzpatrick’s zwift-ds.com site. We also highly recommend using Dave Edmond’s Zwift TTT Calculator tool.