VTTA Zwift '10' 4/2/25 - a spectacular and sudden conclusion!

I'd been somewhat concerned for some time about the state of the bike frame mounted on my Tacx Neo trainer - many years of heavy sweating had corroded it really badly. I had joked recently about it collapsing, and had obtained a replacement. But of course as I awaited parts to arrive, I hadn't set it up.

I completed a decent 40 minute warmup pretty well, though I'd noticed that the gears were sounding a bit rough, and occasionally the rear mech seemed to want to change on its own accord. Oh well, I thought, I have a look tomorrow. A few minutes before my scheduled start ay 19:04, I moved to the start pen and waited a few minutes to start.

My plan for this evening was to focus on holding a steady power of around 240W, ideally a little above. At the start, the gears were pretty jumpy mostly in the starting effort, out of the saddle. Things seemed to settle down a bit and for the first six minutes things went very well. But then I started seeing fluctuations in power and the gear started auto-changing. This was really disruptive and I was contemplating packing when the decision was made for me. Just coming out of the desert turnaround at 10km, the bike frame collapsed and deposited me on the floor in a heap of rusted metal.Luckily, this was fairly slow and I didn't do myself any real damage beyond some bumps and scrapes. I checked that the trainer didn't look too damaged, took a photo and retired indoors. 

Bikes permanently mounted on indoor trainers get a lot of abuse, not least in the volume of salty sweat deposited on them. I generally ride once or twice a day, and have done since Covid lockdown in spring 2020 (I rode less frequently before that), so it's not surprising the frame had suffered. It's just annoying it didn't wait another couple of weeks! I assume the jumpiness of the gears was caused by the frame flexing around prior to snapping and the effect on cable tension.

Still, no lasting damage. I hope, I haven't yet tried the trainer since this incident.

My first DNF in a Zwift event.