I decided to have a go at fixing the freehub attached to the Fulcrum 5s that were on the Cannondale. You may remember that it stopped working on a long ride a few weeks ago, preventing the pedals from engaging the back wheel.
So .. I bought some freehub springs from Amazon and fitted one.
Actually a pretty simple job once you’ve taken the freehub off the wheel – you just wrap the spring, which looks like a slightly oversized cheap keyring, around the groove in the freehub body. The pawls are designed so that the tension in the spring makes them stick out and engage the hub when not freewheeling. I’m no mechanical engineer but I reckon that using a single spring for this is a poor design.
The remaining springs in the pack are shown here:
I gave the innards a good wipe round, and relubed the pawls and the hub. Fortunately the Fulcrum 5 rear wheel has sealed bearing units so I didn’t have to bother with regreasing little steel balls.
Working nicely now. Some freehubs have independently sprung pawls. like this:
.. and that’s surely a better design.
Still to do: swap the 8 speed cassette off Boardman II and put it onto the Fulcrum 5 rear wheel. It’ll need spacers because the Fulcrum freehub is designed for a 10 speed cassette.