M12X1.5 Vs M12X1.75 Bike Trailer Thru Axle Uk
Thread pitch must match your frame exactly. An axle stamped or measured as M12x1.5 is not interchangeable with M12x1.75 — and neither replaces M12x1.0 — even when every option is labelled “12 mm”. UK trailer charts sell separate SKUs for each pitch family; guessing from the bike brand alone is how riders strip threads.
How UK charts group trailer thru-axle pitches
Specialist UK retailers split trailer thru-axle adapters into fine (M12x1.0), medium (M12x1.5) and coarse (M12x1.75) families. The Roof Box Company thru-axle adapter chart is a clear example of that separation for Thule-channel products, and trailer-maker guides list distinct M12 × 1 / 1.5 / 1.75 replacements rather than a single “universal 12 mm” part (Thule UK fit guide pitch families).
Independent Burley retailers in the UK likewise stock 12x1.0, 12x1.5 and 12x1.75 variants side by side (Fawkes Cycles Burley pitch variants).
Comparison table
| Pitch | How riders usually identify it | Trailer-adapter note |
|---|---|---|
| M12x1.0 | Markings on the OEM axle or a printed fine-pitch guide; still appears on some newer frames | Order only the 1.0 family — never “close enough” to 1.5 |
| M12x1.5 | Common medium pitch on many disc thru-axle bikes; confirm with markings | Match 1.5 threads; then confirm length still sits in the trailer adapter window |
| M12x1.75 | Coarser thread spacing; visually different under a pitch gauge | Match 1.75 only; forcing 1.5 into 1.75 (or vice versa) risks frame damage |
If you have not measured yet, start with how to measure a thru axle for a bike trailer before comparing SKUs.
Decision path that avoids brand guessing
- Read any pitch marking on the stock axle first.
- If unmarked, use a printed 1:1 pitch guide or ask a shop to gauge it — do not infer pitch from “Shimano”, “Maxle” or bike model marketing alone.
- Confirm overall shaft length still fits the trailer adapter range you are shopping in (commonly around 160–178 mm for everyday 12 mm hitch axles).
- Only then open the matching M12 option on a product page.
Who should not buy yet
- Anyone choosing pitch from brand reputation instead of a measurement.
- Anyone forcing a mismatched thread because “it almost starts”.
- Riders whose rear end is not a 12 mm thru axle at all (quick-release or solid hub-motor ends need other hitch hardware).
Conditional next step
When pitch and length are confirmed, compare the matching M12x1.0 / M12x1.5 / M12x1.75 options on the ThruSports 12 mm thru-axle adapter page. Pair the axle with the correct seat style using flat vs conical spacer guidance, then run the pre-ride hitch safety checklist before towing.