- Brake pads and crank axle
- Replace the brake pads
- Revise the pedals
- Remove the stirrup
- Remove worn skate
- Insert the skid into the slide
- Set the game
- Revise the pedals
- Unlock the crank
- Unscrew the ring
- Screw in the central nut
- Place the new key
In town and in the country, a "basic" bike is a precious asset. Both utilitarian and fun, it allows you to go shopping or stroll. But a punctual care must be brought to him so that he is always ready to render service.
Brake pads and crank axle
Among the small interventions accessible to all, with minimal tools, two operations are to be performed. The first, quite common, is the replacement of brake pads. The second, less common, is the catch-up of the game of the crankset and the change of crank lock keys.
Replace the brake pads
The brakes consist of two front and rear calipers, two control handles and a transmission system (cables and ducts). When a handle is pressed, the jaws of the stirrup grip the rim between the two pads. The latter, molded rubber, are nested in shoe holders, or supports, fixed on each side of the stirrup.
● Remove the shoe holder. To do this, unscrew the nut that secures it on the jaw with a wrench (usually 10). Remove the worn pad by sliding a screwdriver blade between the rubber and the bracket. Introduce the new shoe into the dovetail groove and slide it with pliers until it stops against the metal stop. Reassemble and tighten the assembly on the caliper, ensuring that the stop is facing forward. Position the pad holder correctly on the caliper. An oblong hole is provided for this adjustment. When tightening the handle, to test, make sure that the shoe is fully on the side of the rim, not on the tire.
● Replacing the front and rear skids in pairs is often accompanied by adjustment of the brake control by acting on the stop of the sheath on a caliper jaw. At rest, the skids must be approximately 2 mm from the rim.
Revise the pedals
The pedal consists of the plate and the cranks. It comprises an axis rotating on two ball bearings, mounted in a cage of the frame, with the possibility of catching the lateral play. The steel cranks are assembled on the shaft by keys, while those of Duralumin, more recent, have a square fitting and are assembled by an axial screw. The axis can take the game, as well as the keys that are matting in use.
● To unlock a tapered key, unscrew the nut with a wrench. Grasp the crank handle with one hand, and then tap the end of the thread with a sharp, clean sledgehammer. Remove the key and release the crank from the axle.
● To adjust the free play of the shaft, slightly unscrew the toothed ring that secures the central nut. If there is no hook wrench, work with a pin punch while hitting a notch in the ring. Tighten the central nut a little and check the correct rotation of the axle, without hard point. Then tighten the locking ring. Replace the crank and insert a new key into the hole, looking for the flat part of the axle. Push in with a blow of the hammer and replace the tightening nut.
Remove the stirrup
The shoe holders are attached to each side of the caliper. The oblong hole of the jaw adjusts its position relative to the rim. To remove it, unscrew the nut.
Remove worn skate
Remove the old shoe from its support by inserting a screwdriver blade and prying. To work more comfortably, hold the shoe holder with vise grips.
Insert the skid into the slide
The sole of the shoe holder is shaped like a dovetail, as is the base of the shoe. Advance it in the slide to the metal stop with a pliers.
Set the game
To adjust the clearance between the new pads and the rim flanks, which should be approximately 2 mm, unlock the sheath abutment initially screwed in fully. By unscrewing it, the game is reduced.
Revise the pedals
The overhaul of the crankset begins with the removal of the right hand crank, to access the adjustable shaft housing on one side. Using a wrench, unscrew the nut from the conical key.
Unlock the crank
Hold the crank with one hand and blow a hammer on the tail of the key to unlock it. If necessary, use a pin punch to extract it. Remove the crank.
Unscrew the ring
The threaded ring internally immobilizes the central nut. If you do not have a special spigot wrench, use a push-button tangent to loosen it slightly.
Screw in the central nut
With an adjustable wrench, tighten the central nut that compensates for the play of the axle. Rotate the other crank to check that there is no hard point. Tighten the ring and oil the shaft.
Place the new key
Replace a new key in its entry hole, its flat in contact with that of the axis. Strike the whip on the head of the key. Screw in and tighten the locknut.