Hub

Front hub
The front hub on the pronto is typically a Sturmey-Archer will likely X-FD. This is a hub with brake. Some variants might use a brake+dynamo variant.

Maintenance
If the brake remains engaged after releasing the brake leaver, there may be a buildup of brake dust inside the hub. If you have an X-FD hub, follow these steps to clear it:
 * 1) Remove the wheel from the bicycle by disconnecting the brake cable and using two 15mm spanners.Front wheel components in order.jpg
 * 2) On the side of the hub with the brake arm, remove the retaining nut using a 15mm spanner. Use another 15mm spanner on the other side of the hub to stop the shaft rotating.
 * 3) Remove the washers. Make a note of the order you take them off.
 * 4) Clean the inside of the hub carefully. Do not get grease, lube or oil anywhere near the brake surfaces.
 * 5) Clean and grease the cam (rotating shaft) of the brake arm.
 * 6) Put everything back together in the reverse order that you took it apart. The brake plate must be centred as you tighten everything up. To do this, clamp the brake closed as you tighten it.Open Front Hub.jpg

Rear hub


The rear hub on the Pronto is typically a Sturmey-Archer X-RD3. This is a planetary-gear hub, which allows you to shift gears even while stopped. Since all parts are internal, maintenance is more difficult but is needed less often.

The hub features built-in Brakes, which are controlled from one of the grips at the Handlebars.

A detailed manual is available on-line.

Some Mailstars are reported to have had a 5-speed hub, though this may have been an after-market upgrade.