Direct drive trainers and carbon frame fatigue

[ms6073]

Have killed a cheap aluminium frame with carbon seat stays a decade or so ago. Aluminium cracked in a chain stay. The very flexible low grade CF seat stays probably enabled it.

I can imagine that if someone sweats a significant amount, then galvanic corrosion might become a factor for alloy frames or frames with mixed tubesets but it is probably a niche issue.

[warthog101]

Have killed a cheap aluminium frame with carbon seat stays a decade or so ago. Aluminium cracked in a chain stay. The very flexible low grade CF seat stays probably enabled it.

I can imagine that if someone sweats a significant amount, then galvanic corrosion might become a factor for alloy frames or frames with mixed tubesets but it is probably a niche issue.

What killed it was the rubbish cf seat stays allowing significant flex. More than the aluminium chainstays liked. You could look down whilst pedalling and watch the BB move from side to side. It was a cheap frame.

[AJS914]

Based on the posts I've seen on various forums and FB groups, I could probably count on one hand how many failures I've seen reported.

And you also don't know how many of that handful of failures is user error - like a clamping error and the bike slips off the trainer.

In fact, I've seen more posts about aluminium handlebars failing from sweat corrosion than carbon frame breaking.

I don't understand people that set up their trainer in a hot box. A portable air conditioner can be found used for like $50-100 used - $200-300 new. Way cheaper than a smart trainer! Once you get your trainer in an airconditioned room, you'll quickly realize that the AC is one of your best ever cycling purchases.