The Part Measurement Pack

The sheets inside this pack

Every one is also available on its own, free. The pack exists so you can print once rather than 6 times.

1. 01Mystery part measurement sheetTSP-ME-01
2. 02Chinese scooter bolt, thread and spanner cardTSP-ME-05
3. 03Wheel bearing size chart and reverse lookupTSP-ME-09
4. 04Scooter brake pad measurement and tracing cardTSP-ME-04
5. 05Before you order a scooter part: checklistTSP-BU-02
6. 06Old part vs new part comparison sheetTSP-ME-08

The problem it solves

The hardest parts to buy are the ones you cannot name. Searching for “that round thing behind the cover” gets nowhere, sellers cannot help without dimensions, and the comparison that would catch a wrong part usually happens after it has been fitted and stopped being returnable.

This pack is the argument for the whole library. An answer engine can tell you what a bearing number means. It cannot let you stand a bearing on a true-size 17mm circle, or lay a brake pad on a 5mm grid and trace round it, or hold a bolt against a printed thread scale.

Every sheet in here is built for the same situation: a part in your hand, no catalogue that covers your machine, and a listing that quotes three numbers without saying what they measure. The answer is always the same — measure the thing you have, in the units the seller works in, and compare rather than assume.

It ends with the two sheets that bracket the purchase: the checks to run before you order, and the comparison to do on the bench while the new part is still returnable.

The mistakes this sheet exists to prevent

• Ordering by badge and model, which is the least reliable information you have about one of these machines.
• Measuring a worn part and ordering those dimensions. Belts wear narrower and rollers wear smaller.
• Printing a sheet with a true-size scale at "fit to page", which silently shrinks every dimension by about six per cent.
• Fitting the new part before comparing it against the old one, which is the moment it stops being returnable.
• Not writing down the markings on the old part. Cast numbers are frequently the real part number.

How to use it

1. 01Print at actual size and check the calibration rule with a steel rule before measuring anything.
2. 02Use one mystery part sheet per part, and photograph the completed sheet to send to a seller.
3. 03Run the pre-order checklist before searching, not after finding something that looks right.
4. 04Do the old-versus-new comparison on the bench, before fitting.