Marinos

Nice topic and information. As said above, I'd also go for the aluminium with great components

vader957

The aluminum frame probably has better component. In the entry-level carbon, a lot of corners were cut to make it affordable. I would only go with carbon if i plan on upgrading the parts over time.

Jrasero

There is a reason why all professional cyclists use carbon bikes and why a lot of MTB riders has transitioned to carbon ones. Everyone brings up good points but I will just add that carbon simply isn't as impact resistant as metal frames and detecting cracks or delamination 100% is nearly impossible unless it's x-rayed which is really impractical or ultrasonic testing is done by a trained professional which isn't cheap or readily available.

If the thought of catastrophic carbon failure or the high cost of replacement/repair bugs you than yeah look to aluminum which is similar-ish on weight to carbon but has better impact resistance but can also fatigue. Steel can be just as light as carbon but then is insanely expensive and then rigidity comes into play. Titanium seems like the wonder bike especially for MTB but the biggest concern in my book is cost since a frame a lone can easily cost $2K-$3K.

Steve B.

Well stated. I might, over many, many years, crack my aluminum mt. bike frame, probably won’t my carbon road. If my carbon takes a weird hit though it’s toast and that could happen a week after purchase, where as the aluminum may take a decade or more of constant abuse before fatigue becomes an issue. Bikes, except the super light models, are designed to take a lot of abuse where fatigue comes into play. Carbon is typically not designed to take an odd hit like a stick poke into the downtube, which happened to a buddy.

Its much easier though, to design in ride quality with carbon. Harder and more expensive with metal bikes, with titanium being the most expensive.