What Size Bike Rack Light Do You Need?

The question I get more than any other is some version of: which one do I actually need?

It's a fair question. We build the lights in three sizes — Small, Medium and Large — and those names don't tell you much on their own. So here is what is actually different between them, in the order that matters.

Start with your rack, not with the size

Before anything else: check whether we already make a kit for your rack.

Almost everything we build is rack-specific. Not "universal, should fit" — engineered for one rack model, with a bracket that matches that rack's profile and mounts to it without adapters or guesswork. Start at lights by rack brand and find yours. We cover Kuat, 1Up, Thule, Swagman, QuikrStuff, RockyMounts, Yakima, Hollywood, Saris, Cravot and Rig'd.

If your rack is on that list, your decision is just which size. That's the rest of this post. If it isn't, skip to the last section and I'll tell you what to do instead.

Forget the sizes. The first decision is one light bar or two.

Before you think about inches, decide whether you want a single fixture across the middle of your rack, or two separate fixtures, one on the left and one on the right.

That single choice determines how your turn signals behave. It is also the thing most people don't find out until the lights are already on the car. All three photos below are the same rack — a RockyMounts Gigawatt — in the same driveway, so you can see for yourself what each one actually looks like fitted.

Small Light — Single 16-inch

One 16-inch fixture with twelve LEDs, mounted in the center of the rack.

The Small — one 16-inch fixture, centered, on a RockyMounts Gigawatt. One bar, one lit strip.

Here is how it behaves. With your tail lights on, six of the twelve LEDs come on at partial brightness. Hit a turn signal and the LEDs animate — they sequence left or right, the way a lot of modern taillights do. Hit the brakes and all twelve come on at full brightness, overriding the turn signal.

It is the cleanest looking of the three and the least expensive way into a Kody kit. It's a good fit on shorter racks and one- or two-bike setups.

One real catch. Sequencing does not play nicely with newer Fords — we've seen it as far back as 2016 — or with Teslas. The Small always sequences, so if you drive one of those, this isn't the one for you. Go to the Medium, or a Large with one of the non-sequencing fixtures. I'm telling you here because I'd rather you read it now than call me about it after installation.

Medium Light — Double 12 to 13-inch

Two separate fixtures, one on each side of the rack, so your left and right signals are genuinely independent — left side flashes for a left turn, right side for a right turn.

The Medium — two fixtures with a gap between them. That gap is the whole point: each side signals on its own.

The Medium never sequences — the whole fixture flashes. That's a real trade: you give up the animation, and in exchange you get independent left and right signals and no compatibility argument with your tow vehicle. It's the simplest safe answer if you drive a recent Ford or a Tesla.

Total width of the lights plus bracket is just under 27 inches. There's also a 13-inch version of the fixture that adds a built-in reverse light behind a white lens, which needs a 7-blade connector to work.

Large Light — Double 16-inch

Same idea as the Medium, bigger fixtures. Two 16-inch lights, one per side, total width just under 33 inches including the bracket.

The Large — two 16-inch fixtures, nearly meeting in the middle. Compare the reach against the Small further up the page.

This is the most visible setup we make. If you're carrying three or four bikes and you want no ambiguity about where the edges of your load are, this is the one. Reverse lights are available here too with a 7-blade connector.

One thing to watch on the Large: the fixture choices include a sequencing option as well as the basic flashing ones. If you drive a recent Ford or a Tesla, pick a non-sequencing fixture. Going double is not on its own enough to avoid the problem.

Worth saying plainly: in a photograph the Medium and the Large look almost the same. The honest difference is about six inches of overall width — 27 inches against 33 — and on the Large the two fixtures nearly meet in the middle rather than sitting apart. What both give you, and the Small doesn't, is two separate fixtures signalling independently. If you're choosing between the two doubles, choose on rack width and bike count, not on how they photograph.

How to actually choose

Four things decide it:

Your tow vehicle — a recent Ford or a Tesla means no sequencing light, full stop. The Small always sequences, so it's out. The Medium never does. The Large is fine provided you don't choose the sequencing fixture. This one is not a preference, it's a compatibility issue.

How many bikes you carry — one or two bikes on a shorter rack, the Small is clean and does the job. Three or four bikes, go double. More bikes means more of your vehicle's own lights are blocked, and two fixtures spread across the rack read much more clearly to the driver behind you.

Reverse lights — only available on the double kits, and only with a 7-blade connector.

License plate — plate holder options are straightforward on the Small and Medium. On the Large, talk to us first.

Three more things to decide

Cable length — we offer Short at 70 inches, Long at 112, and Extra Long at 160. Short handles most racks up to four bike trays. This is driven by your rack, not your light size — different question, same order form.

Connector type — a 4-pin flat runs tail, turn and brake lights. The 7-blade adds a heavier cable and jacket, a license plate light circuit, and it's required for reverse lights. If you're not sure which one your vehicle has, our guide to trailer connector types walks through how to tell.

License plate holder — three options: none at all, a holder with no light, or a holder with an integrated plate light and wiring.

If we don't make a kit for your rack

Then you want the Flex Universal, at $160.

The Flex is the one universal kit I'm comfortable recommending, because it doesn't depend on your rack having a particular shape. It straps or cable-ties to essentially anything — Voile straps and cable ties come in the box, and there are quarter-inch holes if you'd rather screw it down. Same 16-inch, twelve-LED bar as the Small. We've tested it on the Kuat Sherpa, RockyMounts SplitRail and MonoRail, Yakima DrTray and Saris MHS, but the point of it is that it goes on things we've never seen.

It's also the answer for cargo carriers, hitch baskets and anything else back there that's hiding your lights. The rest of them are on our universal lights page.

What I'd pick

If you drive a recent Ford or a Tesla, one decision is made for you: no sequencing light. That rules out the Small, and on the Large it means skipping the sequencing fixture. The Medium is the simplest safe answer.

For everyone else, start with your rack. If we make a kit for it, take it — the fit is the whole point. Then pick by how many bikes you carry: one or two, the Small; three or four, the Medium double is the one I recommend most often. The Large is for when you want to be genuinely impossible to miss.

Every one of these is built the same way underneath: powder-coated steel and aluminum brackets, stainless hardware so nothing rattles loose, and a one-year warranty.

And if you're still wondering whether you need any of this, read the day I learned my bike rack was hiding my brake lights. That traffic stop is the reason this company exists.

Find your rack

If you already know what you're running, go straight to it:

Kody lights for Kuat bike racks · 1Up · Thule · Swagman · QuikrStuff · RockyMounts · Yakima · Hollywood · Saris · Cravot · Rig'd Supply RamblerRack · Universal

Not sure which rack you have? Start at the lights by rack brand page.