Watts Up in Watopia: Mismatched MTU

This week, I’m sharing an easy fix for any of you running Zwift on a Windows computer who is experiencing extremely slow loading.

For longer than I’d like to admit, my partner and I have been experiencing long load times for Zwift. Like, really long. We are running Zwift on our boys’ gaming PC. And, Zwift has been taking 20-30 minutes to load. If we wanted to do an event, we had to get the process started at least 45 minutes before, which is not convenient for our crunched schedules. I have been late to join the Friday Festina Lente workout several times because of this issue.

I wrongly assumed that our boys’ PC was overloaded with videogames. We have plenty of space and processing power, so why the long delays? A reinstall of Zwift did not help.

After some digging online, I discovered that we were experiencing a Maximum Transmission Unit (MTU) mismatch. Now, I’m no computer wiz, so I won’t pretend to know what this means. All I know is that I followed these instructions that I found on Reddit, and my problem was easily solved. I’m now loading Zwift in 1-2 minutes. One additional tip I needed to learn was how to run a Command Prompt as an administrator.

I’m sure the computer experts reading this are shaking their heads. That’s ok. This simple fix helped me regain some time in my day (and sleep). So, I thought I’d share it in case anyone else also needed this fix.

Check out what we have planned this week on Zwift.

Guest World Schedule


Here’s this week’s guest worlds, so you can plan to earn some of the route badges you are missing:

Monday: Makuri Islands & New York
Tuesday: Makuri Islands & New York
Wednesday: Richmond & London
Thursday: Yorkshire & Innsbruck
Friday: France & Paris

Slowtwich Indoors Event Preview (All Times Eastern)


Go to Zwift Events to sign up for these rides and runs.

Monday Group Run, 7:00 AM & 7:00 PM
Join us for a group run on the virtual track of May Field that will kick start your week.

Tuesday Ride of the Valkryies Workout (Women Only), 6:00 AM
This event is by and for women. It’s an almost no-drop, rubber-banded Structured Training workout, featuring a warm-up, set of intervals, and a cool-down. This week’s workout is Mix It Up.

Tuesday Structured Training, 7:00 PM
Our Tuesday ride features triathlon-focused cycling workouts written by coaches and pro athletes affiliated with Slowtwitch. The workouts last 60 minutes and will help add variety and interest to your weekly training schedule. This week’s workout is A Little Bit of Everything.

Wednesday Group Run, 7:00 AM & 7:00 PM
A more scenic group run on the Quatch Quest course.

Thursday Rise & Grind, 5:35 AM
This workout is a 55-minute early morning bracer for the East Coast crowd. Be sure to get a warm-up in and enter the staging area at least 5 minutes before the start. The groups will be fenced with the exception of designated KOMs and sprints, as well as the last 10 minutes of the ride. This ride is double-drafted, so don’t let gaps open up, or you’ll be off the back quickly!

Thursday Hilly Vanilli Chase, 6:55 PM
This double-drafted ride uses a chase format with the D group getting a 5 minute head start on the C group, which will get a further 5 minute head start on the B group. The goal is to have all three groups complete roughly the same amount of distance by the end of the ride. The D and C groups will utilize the fence until they are caught by the group behind. Teamwork is key to the groups catching or staying away. Gather some friends and get them organized to chase!

Friday Festina Lente, 9:00 AM
This structured training workout is designed to get you geared up for the weekend. Roughly translated as “make haste, slowly,” Festina Lente features a workout that will get your engine running but still leave some in the tank for the big rides and races you have planned for the weekend. This ride is led by members of the Kanberra Cycling Team as lead beacon. August will feature a progression of four workouts designed by Craig Polston of EVOQ.BIKE. This week’s workout is Threshold+Bursts.

Other Events to Watch For


ZHR Masters
Have you ever wanted to race within your age group on Zwift? Look no further that Zwift Handicap Race (ZHR) Masters events. On Tuesdays, there are five times to compete in a road race within your age group. On Thursday, there are another five times to compete within a time trial by age. Join the correct age category divided into the following 10-year bands, where your age is your actual age on December 31st of the current year.

A: 30-39 years
B: 40-49 years
C: 50-59 years
D: 60-69 years
E: 70 years and over

Female racers join one category up. For example, if you are 35, you race as a Category B. After the race, results are further sub-divided on ZwiftPower into UCI 5-year bands. Join these races to see how you compare within your age group.

Zwift Academy Road: Win a Pro Contract
Curious how you would stack up in a Pro Contender competition? Well, it’s not too late to sign up for the Zwift Road Academy. First, sign up for the Academy by September 27th. Second, graduate from the Academy on or before October 24th. Next, complete two additional Pro Contender events on or before October 1st. Five women and men will be selected to compete in the Zwift Academy Finals. Two contenders will be crowned champions, winning a pro cycling contract with CANYON/SRAM Racing (women) or Team Alpecin-Fenix (men). Take your shot and see how you rate in comparison with the top contenders.