Sad but true that Stu Parkinson’s Claud Butler Urraco is getting on a bit. I’ve been helping him keep it running over the last few years but the rear hub and freewheel recently gave up & it’s looking like he’s thinking it’s new bike time.
What’s a freewheel you ask???
Traditionally the centre of a rear wheel (the hub) had a screw thread on the end of it and the ‘freewheel’ (sprocket cluster and ratchet mechanism) screwed on to this. The screw threads were standardised so any brand of freewheel could be attached to any brand of hub.
In the late 1980‘s / early 1990‘s the Shimano ‘Freehub’ was released. The major advantage of this system is the ratchet mechanism (Freehub) forms part of the hub body. As the ratchet mechanism usually has a longer life than the sprockets, when you wear out the sprockets on a Freehub system you can simply replace the sprockets (the ratchet mechanism can also be replaced if needed).
and I’m telling you this because?
One of my main ‘turn to’ places for mechanical bike information is Sheldon Brown’s website. It looks basic but has got an unrivaled level of detail (particularly for older equipment) & has helped out numerous times with Stu’s bike. Definitely makes recommended viewing if you’re in to your DIY bike maintenance: