What are the grades of Shimano derailleurs?

[SebastianRose]

Shimano derailleurs are classified into 8 grades, listed from highest to lowest: XTR, XT, LX, Deore, Alivio, Acera, Altus, Tourney. Derailleur grade classification basis: The Tourney series derailleurs are mainly used for urban leisure bikes and entry-level XC; ALTUS to DEORE represents a progressive upgrade for XC applications; SLX and above belong to competition-level mountain bike components, with wider applicability - besides XC, they can also handle AM, FR or DH.

[DeOlive]

I've been riding mountain bikes for five years and have disassembled and installed quite a few Shimano derailleurs. The road bike series is mainly divided into these tiers from high to low: the top-tier Dura-Ace for racing, which offers ultra-precise performance; next is Ultegra, which has strong performance but is much cheaper; then there's the 105 series, which many enthusiasts use for their first good bike; the entry-level options include Tiagra and Sora, which are sufficient for commuting; and the most basic is Claris, often used by students to upgrade old bikes. For mountain bikes, there are series like XTR and Deore, with completely different cassette gear ratio designs. Choosing a tier mainly depends on budget and purpose. If you're commuting daily, a Tiagra is enough, but for off-road riding, it's recommended to start with XTR.