By long-distance bus

The international coach into Uruguay is comfortable, frequent, and well run. It has exactly one complication for a cyclist: no company publishes a bicycle policy. Whether your bike rides in the luggage hold is settled case by case, by phone, ahead of time — so the single most useful thing you can do is call a few days before you travel and confirm there's room.

Wherever you start, you arrive at the same place: Tres Cruces, Montevideo's main bus terminal. From Argentina the coaches leave Buenos Aires and cross at the Fray Bentos bridge; from Brazil they come down from Porto Alegre — and, in season, Florianópolis — crossing the coastal border at Chuy. The Argentine run is around eight hours; the Brazilian one closer to twelve.

With no published rule, the working practice is the one used on Argentina's domestic routes: front wheel off, the bike wrapped in cardboard or film, and a modest surcharge paid at the counter. Pack it as you would for a flight and you'll rarely have trouble — it's the call ahead, not the packing, that saves you.

By bus the border is handled for you, with one pause: at Chuy, passengers get off at the immigration post out on the highway while the driver collects the passports, border formalities can take a while — leave yourself plenty of time. A bicycle is generally treated as personal luggage, but it's worth checking at the border. Leaving Argentina, the customs service may note the frame number or fasten a seal — more likely if the bike looks new; a bike with some wear behind it usually passes without fuss.