Brenvik Hitch

Nose weight is the figure most towing setups guess at, and it is the one that decides whether the trailer tracks or hunts. Brenvik Hitch works it out from where the load actually sits.

Enter the rig once: kerb mass, GVM, GCM, braked towing capacity, tow-ball limit, trailer tare, ATM, empty nose weight, and the distance from the coupling to the axle centre. Everything after that is arithmetic the app does for you.

The load plan
Add each item with its mass and its distance from the coupling. The plan applies the lever about the axle — a 45 kg tool chest 60 cm back adds 38 kg to the ball; two bikes 40 cm behind the axle take 4 kg off it — and returns:

- nose weight in kg and as a share of loaded trailer mass
- loaded trailer mass and the load carried by the trailer axles
- combination mass
- trailer payload still available

Six limits, checked on every change
Trailer mass against ATM. Trailer mass against the braked towing capacity. Nose weight against the tow-ball limit. Kerb plus nose against GVM — the check that puts a legal trailer over the vehicle's own limit. Combination against GCM. And the nose share against the 7–15% band, flagged light or heavy with the actual figure, not a shrug.

Each one shows the pair of numbers and the margin left, so you can see how much you have before you load, not after.

Twelve pre-tow checks
Coupling, chains, breakaway cable, lights, brake test, jockey wheel, pressures, wheel nuts, straps, mirrors, nose weight, chocks. Ticked state persists between sessions and clears when you want it to.

Reference
Tare, ATM, GTM, GVM, GCM and nose weight defined in one screen each, plus how to measure ball download with bathroom scales and why the 7–15% band exists at all.

Multiple rigs, dark theme, portrait, no account. The build declares one permission — vibrate — and contains no networking code at all.

Aimed at anyone who tows more than once a year: caravans, plant trailers, boats, horse boxes, box trailers. Figures are yours to verify against the plates on your own vehicle and trailer; the app does the arithmetic, not the compliance.