Buying guide · 5 min
BMX multi-tool: the good one has a 17 mm socket
Two multi-tools reviewed the BMX way: the Odyssey Travel Tool, with a 17 mm socket for axles and pegs, and the Crankbrothers M19, the 19-function general tool.
Guide updated
Quick answer: For a BMX, the right multi-tool is recognised by a single piece: the deep 17 mm socket, the size of axle nuts and pegs. Almost every bike multi-tool is made for MTB or road bikes and leaves it out, so it cannot remove a BMX wheel. The one that includes it is the Odyssey Travel Tool; the most complete general alternative is the Crankbrothers M19, with 19 functions and a chain tool, but without that socket.
The multi-tool is the item that decides whether a session ends at the park or pushing the bike home. But there is a trap: almost every multi-tool on sale is made for MTB or road bikes, and a BMX needs one thing most of them lack. This guide is ordered by a single criterion: what it can actually take apart on your bike, not how many functions the maker counts.
The two, at a glance
What a BMX multi-tool must include
- A deep 17 mm socket. It is the size of the axle nuts on most BMX bikes and the one that tightens pegs. Without a 17 mm socket the tool cannot remove a wheel: on a BMX it is the function that matters.
- 4, 5, 6 and 8 mm hex keys. Stem, bars, seat post and cranks all move with those sizes.
- A 15 mm pedal wrench. Pedals go on and off with it on most cranks.
- A real chain tool. A BMX chain is single-speed (1/2" × 1/8"), thicker than a geared chain: a breaker designed only for 8–12 speed chains can fall short.
- Leverage, in a pocket size. Axle nuts are tight: you need a long enough arm to loosen them, in a tool that still fits your bag.
1. Odyssey Travel Tool: the one designed for BMX
Odyssey is a BMX brand and its multi-tool shows it: it is the one in this guide with the deep 17 mm socket, on a full-length arm for the leverage an axle nut demands. It folds like a pocket knife, and the socket itself hides a storage compartment for a spare link or loose bolts. In practice it is the minimum workshop for building or stripping the whole bike at the spot.
Specs and cons of the Odyssey Travel Tool
According to Odyssey: 7 functions in 1 — 4, 5, 6 and 8 mm hex wrenches, a deep 17 mm socket with an integrated storage compartment, a pedal wrench with 15 and 17 mm spanners and a full-length arm for leverage.
Cons: it has no chain tool (Odyssey sells it separately, also in a bundle with this tool), no spoke wrenches and no Torx. And if your bike’s axle nuts are 14 or 19 mm, the socket will not fit: measure them before buying. Pros and cons ↓
2. Crankbrothers M19: the complete one that is not for BMX
The M19 is probably the best-selling multi-tool in general cycling: 19 functions in 175 grams, with a chain tool and even spoke wrenches. For hex adjustments, truing a wheel or general emergencies it is excellent. Its limit on a BMX is the usual one for general tools: there is no 17 mm socket, so axle nuts and pegs stay out of its reach.
Specs and cons of the Crankbrothers M19
According to Crankbrothers: 19 functions — 2, 2.5, 3, 4, 5, 6 and 8 mm hex wrenches; a chain tool for 8 to 12 speed chains; spoke wrenches 0, 1, 2 and 3; 8 and 10 mm open wrenches; Phillips 1 and 2 and flat 2 screwdrivers; Torx T10 and T25. 175 g, 89 mm long, a 6061-T6 aluminium body, high-tensile steel tools and a lifetime warranty.
Cons: with no 17 mm socket it cannot remove axle nuts or fit pegs on most BMX bikes, and its chain tool is designed for geared chains, narrower than a 1/8" BMX chain. It also carries sizes a BMX barely uses (Torx, 2 mm hex). Pros and cons ↓
| If you need… | Choose |
|---|---|
| One tool that strips the whole bike, axles and pegs included | Odyssey Travel Tool |
| A chain tool and spoke wrenches in the same body | Crankbrothers M19 (knowing 17 mm axles stay out of reach) |
| Your bike has 14 or 15 mm axle nuts | The M19 covers almost everything: check your size before deciding |
| It is a gift for a rider | The Travel Tool: the gift that actually gets used (more ideas in the gift guide) |
And the lock? For the short stop, not the street
The multi-tool’s natural partner in the bag is a small lock, and honesty matters here: a thin cable does not protect a bike, it only deters the opportunist during the stop where the bike stays in sight — the water fountain, the corner shop. Odyssey sells a retractable cable lock made exactly for that, bundled with the Travel Tool and its chain breaker. To leave the bike on the street out of sight, the serious minimum is a hardened U-lock, and even then only briefly: no bag-sized lock stops someone with cutters and a minute.
Common mistakes when choosing a multi-tool
- Buying by function count: 19 functions without a 17 mm socket cannot remove your wheel; on a BMX one size rules.
- Not measuring your axle nuts: most are 17 mm, but 14, 15 and 19 mm axles exist; your bike’s size decides the tool.
- Assuming a geared chain tool fits: a 1/8" BMX chain is wider; if you break chains often, buy a dedicated BMX chain tool.
- Trusting a giveaway cable lock on the street: a thin cable is cut in seconds.
Complete the bag kit with the right pump and what the BMX maintenance article explains; if your chain is due a change, the BMX chain guide covers sizes and tension. And if the tool is a gift, the BMX gift guide has more size-free wins. The two multi-tools with their verified specs are just below.
Frequently asked questions
Why does the 17 mm socket matter so much?
Because it is the axle-nut size on most freestyle BMX bikes and the one that tightens pegs. Without that socket a multi-tool cannot remove a wheel or fit pegs: it may tighten your stem, but the bike does not come apart.
Does an MTB multi-tool work on a BMX?
For hex adjustments, yes: stems, bars and seat posts use the same sizes. For wheels and pegs, no, unless it has a 17 mm socket, and MTB tools almost never do. Also check your nut size: 14, 15 and 19 mm axles exist.
Does the M19 chain tool work on a BMX chain?
It is specified for 8 to 12 speed chains, which are narrower than a 1/2" × 1/8" BMX chain. It may push a pin out in an emergency, but that is not its job: if you break BMX chains often, get a dedicated 1/8" chain tool.
Which lock is OK for leaving the bike on the street?
No thin cable: it is cut in seconds. The serious minimum is a hardened-steel U-lock around a fixed point, and even then only for short spells, with the bike in sight whenever you can. A retractable cable is for the short stop, not the street.
Why don’t you give prices or scores?
Because prices change often and we don’t want to give you a made-up score: we’d rather help you pick the right tool for your bike. You will see today’s price on the shop listing.