The jockey wheels on the chain tensioner are made of a durable nylon material
Over time these will wear and could help cause the chain to slip when under load
It is common to replace the complete chain tensioner assembly - but it's possible to replace just the jockey wheels and associated components to save some money
This derailleur jockey wheel pack consists of the following items:
Pair of jockey wheels (idlers) for derailleur (2 or 6 speed) Brompton chain tensioners - 10 tooth
Bearings (pair - approx 19mm long with a diameter of 6mm
Fixing nut (approx 30mm long) and bolt (pair)
Washer (pair)
Dust cap (pair)
It allows you to replace just the worn jockey wheels on a Brompton chain tensioner
Tip: to keep your jockey wheels lasting longer (this applies to all drive chain components) - keep them clean from dirt / too much oil as this will cause them to wear quicker
Tools required:
2.5mm allen key / hex wrench
10mm spanner
small flat head / blade screwdriver