Gravel Bikes

Gravel Bike Buying Guide

Road-Biased vs Off-Road-Biased

Gravel bikes sit on a spectrum. Road-biased gravel bikes (Cervélo Áspero, 3T Exploro, BMC URS) have tighter geometry, narrower tyre clearance (38-42mm), and prioritise speed on smoother surfaces. Off-road-biased bikes (Salsa Cutthroat, Bombtrack Beyond, Surly Midnight Special) have slacker geometry, wider clearance (45-50mm+), and more mount points for bikepacking. Most mainstream gravel bikes (Diverge, Grail, Checkpoint) sit in the middle. Think about where you'll actually ride most — 70% road and 30% gravel needs a different bike than 70% off-road.

Tyre Clearance and Wheels

Tyre clearance is the defining spec. 700c x 40mm is the standard gravel setup. Some frames also accept 650b wheels with tyres up to 2.1" — a fatter, more MTB-like setup for rough terrain. If the frame supports both wheel sizes, you can swap between 700c for road-heavy days and 650b for rough stuff. Tubeless is strongly recommended for gravel — lower pressures for grip without pinch flat risk. Gravel-specific tyres like the Panaracer GravelKing, WTB Riddler, and Schwalbe G-One are designed for mixed conditions.

Groupsets for Gravel

1x drivetrains dominate gravel — a single chainring with a wide-range cassette. SRAM pioneered this with Force and Rival XPLR (10-44 cassette range). Shimano GRX is the dedicated gravel groupset in both 1x and 2x versions. 1x is simpler (no front derailleur, less to go wrong), but 2x gives a wider overall range and closer gear steps — better if you ride significant road sections. A 40T or 42T chainring with an 11-42 or 10-44 cassette covers most gravel riding. Shimano GRX levers have a wider hood shape and more flare than standard road levers for better control on rough ground.

Frame Features

Gravel frames are loaded with mount points: three bottle cages minimum, rack and mudguard eyelets, top-tube bag mounts, and fork cargo mounts for anything bags. Dropped chainstays and seatstays create mud clearance. Many gravel frames use a dropped bottom bracket (75-80mm drop) for stability at speed on loose surfaces. Carbon gravel frames save weight; aluminium is tougher for bikepacking abuse; steel and titanium offer comfort and repairability for remote adventures.

Buying Used Gravel Bikes

Gravel bikes take more abuse than pure road bikes. Inspect the frame for stone chip damage — check the down tube and chainstays especially. 1x chainrings and wide-range cassettes wear faster than 2x setups due to increased chain angles. Check dropper post function if fitted (increasingly common on gravel bikes). Verify through-axle threads aren't cross-threaded. Gravel bikes with bikepacking-specific features (mount points, frame bags, dynamo hubs) command premiums used — they're worth it if you actually tour.