[Psychlist]

The author was comparing carbon to steel, and that's very different.

Steel yields gently so most people have learned to tighten things until they feel the bolt start to yield, then stop. With aluminium that's harder, and with carbon it basically doesn't happen. You need to be careful, ideally use a torque wrench, and always check for cracks in your carbon bike.

A friend was "helped" by someone a while ago and their carbon MTB now has a crack where the seatpost bolt does up. It seems to be ok and they know to watch that area. But I'm ok with it because when it does fail... the seatpost drops and couple of cm into the frame and gets loose. That's pretty survivable.

Said friend-of-friend also helped change the oil in their car. Overtightening an oil filter is much less survivable (for the car). Filter split, oil everywhere, had to get towed to service centre and replaced. Oooops.

[KennyBlanken]

The author is a retrogrouch parroting the usual bike myths you hear over and over.

Aluminum, steel, carbon, etc are materials that can be engineered out to wazoo to have different qualities, many of them overlapping. Aluminum bikes can be wet noodles and steel bikes can be bone-jarring stiff. A big-box-store aluminum bike is nothing like a race bike made from high-end reynolds aluminum. Etc.

[taffronaut]

I badly cracked the head tube on my run-of-the-mill steel frame (Reynolds 501 CrMo) and a guy recommended by a bike shop welded it up for me for £25. Six years later it's still going strong.

[altarius]

I bought a carbon fiber framed Trek Remedy enduro/all mountain bike and repaired a fist size hole/delamination in the downtube at home for about $50 in materials [1]. Five years later it's also fine.

And I've taken the bike off 6ft drops and ridden it decently hard most of it's restored life.

CF repair can be done and plenty strong, it's just more risky because the properties aren't isotropic and simple like steel/alu so you can't just weld in a piece of metal of roughly the same thickness. I would not want to repair a bike I don't ride myself.

[1] https://medium.com/@fixingthings/fixing-a-trek-remedy-29-9-8... (yes, sorry it's medium)

[mgarfias]

I’d be careful welding aluminum. At the factory, post weld, the frames are then heat treated, and pulled back into shape (the heat treatment will distort them).

Welding after heat treatment will reduce the weld affected zone back to its basic untreated properties.

[taffronaut]

That's a very impressive carbon fibre repair.