Fit guide · Compatibility · UK 2026
Does my bike fit the trailer?
Most trailers attach near the rear axle on the non-drive side. The trailer itself is rarely the problem — the real question is which axle you have, and whether the dropout next to it has room for a hitch to sit flush. Two minutes here will tell you.
01 · Find your fit
Two ways to know.
Pick yours.
Either you already know the trailer you're eyeing and want to check your bike compatibility — or you know your bike, and want to see which trailers fit.
Can't see what you're looking for? We source most major trailer brands. Ask us — one working-day reply.
02 · Reference
The technical bit, if you want it.
You don't need any of this to use the tools above. But if you're curious about which axle you actually have — and why the shape of the dropout matters — it's all here in one place.
Road · Hybrid · Older MTB
A thin 5 mm skewer with a flip lever on the non-drive side. The easiest case. The trailer's supplied hitch usually clamps directly to the skewer or sits between the skewer and the dropout.
● Usually fits with supplied hitch
Modern MTB · Gravel · Road disc · Many e-bikes
A thick 12 mm axle that threads through the hub into the dropout. You'll almost always need a replacement axle sized to your hub — Robert Axle Project, Burley or Croozer make one for most bikes.
● Adapter axle required
City · Single-speed · Some e-bikes
Two nuts hold the wheel on. Common on hub-gear bikes and rear-hub-motor e-bikes. Usually fits, but check there's at least a few millimetres of exposed thread beyond the nut for the hitch to clamp to.
● Usually fits — check exposed thread
Dutch-style · Commuter e-bikes
Gears live inside the rear hub. A non-rotation washer, cable arm and shifter cable all live around the axle. A standard hitch may not clear — most brands sell a hub-gear-specific axle nut hitch.
● Needs hub-gear-specific hitch
Many cheaper e-bikes · Conversions
Motor lives inside the rear wheel. Often non-standard axle hardware, torque washers and a power cable exit point near the dropout. Don't guess — and many manufacturers don't approve towing on this setup at all.
● Manual check required
Lightweight road · Race · Triathlon
Carbon frames and integrated dropouts often aren't rated for towing forces. Get manufacturer approval first — and if you're towing regularly, an aluminium or steel bike is a kinder choice.
● Manufacturer approval required
These decide which replacement axle threads into your bike. Measure yourself, or send us a photo, model name & year — we'll work them out for you.
01 · Diameter
12 mm
Most common. 14 mm on some MTBs.
02 · Thread pitch
M12 × 1.0 / 1.5 / 1.75
Look for the marking on the axle head.
03 · Hub width
142 · 148 · 157 mm
Boost 148 is dominant on modern MTB/gravel.
The flat, square-cornered plate at the end of the chainstay. Plenty of clean metal next to the axle — the hitch clamps on and sits flush. This is the goal.
A curved or shrouded dropout — common on disc-brake bikes. The hitch can't sit flat against it. A small flat-plate adapter (or in some cases a longer thru-axle) restores the contact face.
A rear-facing slot rather than a closed hole — found on single-speeds and some old roadsters. Trailer pulling forces can shift the axle backwards. We don't recommend an axle-mounted hitch here without a chain tug or frame-mount alternative.
03 · Ask a human
Send us your bike. We'll confirm the fit.
A 30-second job. Fill this in with a photo or two of your rear axle. Someone from our workshop replies within one working day, with the exact trailer or adapter you need. Free, no obligation.
04 · Common questions
Asked a lot
Five years of fitting trailers to various kinds of bikes, distilled. Different question? Just ask us.
Usually yes — but always check the manufacturer's manual first. Some e-bike makers explicitly prohibit towing and will void the warranty if you do. Mid-drive e-bikes (motor at the cranks) are generally simpler than rear-hub-motor e-bikes, which have unusual axle hardware. Send us the model and we'll tell you what the manufacturer says.
A thru-axle is a thick (usually 12 mm) axle that threads through the hub into the frame, instead of being held by a thin skewer with quick-release levers. Most modern disc-brake bikes use them. Trailers can't clamp onto a thru-axle the way they do onto a skewer — so the original axle gets replaced with a trailer-compatible one of the same length, thread pitch and diameter.
Usually fine, but it's the most common cause of "almost fits". Rear racks and stand-alone kickstands often share the dropout bolt with the trailer hitch — the fix is normally a longer bolt or a spacer. Send us a photo with everything in place.
If you're handy, yes — you'll need a calliper for the diameter, a thread gauge for the pitch, and a tape for the hub width. Most people find sending us a couple of photos quicker. We work it out for you and confirm before you order.
07 · Next step
Ready when you are.
Run the checker again, browse the trailers you can now buy with confidence, or hand it to a human.
