Both wheels are fitted
with Shimano 'Inter M' roller-hub brakes. The front one shown here is fitted to
the left-hand side of the hub, and sits on a splined or toothed shaft protruding
from the wheel hub. It is held in position on the axle by a nut and spring
washer on the inside of the forks.
The body of the brake is static with the axle, and is braced in position by a calliper protruding from the wheel side... this calliper locates freely into a welded loop on the inside of the forks and provides bracing strength when the brake is applied.
A standard brake cable pulls the mechanism tight whence the mechanism clasps the inner, rotating portion, slowing the bike down. The action is surprisingly progressive, and resists skidding and tyre wear as the action is less aggressive than rim-brakes. As the point of action is different, it's also harder to throw oneself over the handlebars... it is virtually impossible to cause the rear of the bike to rise, even in emergency situations.
These brakes are almost totally unaffected by water (the main reason for choosing them - normal brakes become useless in wet weather) and are almost completely silent. Wear is virtually non-existent, the only adjustment required being periodic adjustment of the cables to compensate for stretch, evident in all cable operated brakes. A greasing point is provided to ensure continued silent operation and suitable progression of action.
The main disadvantage with this system is that removing the wheel for puncture repairs an so forth is more troublesome. The calliper must be located carefully on removal and subsequent refitting of the wheel, and the brake cable must be disconnected. The cable clamp bolt and sheath retainer are designed to be slid out from the calliper, but this can be tricky on the road. The other disadvantage is heat... these brakes can get very hot, as evidenced by the aluminium heat sink at the rear of the assembly. It's easy to burn fingers when not thinking during a hasty roadside repair!
Find out more about Shimano 'Inter M' roller brakes here.