Bontrager 231793 Front hubs- Loose ball, semi-cartridge Formula FCM, While turning the end

Fig. 5B

Seal not seated

Bearings in ball cup

Bearing seal

Fig. 10B

Fig. 8B

Fig. 9B

Fig. 6B

Fig. 7B

Front hubs- Loose ball, semi-cartridge; Formula FCM

'99, 2000, 2001 Bontrager Race, Race Disk front wheels

Recommended tools

13mm cone wrench 17mm cone wrench Adjustable wrench Hammer (soft faced) Small slot screwdriver

DISASSEMBLY

Hub parts and names are referenced on next page.

Remove the axle

Fig. 1B

1. Remove external seals

External seal(Fig. 2B) with a screwdriver. Be careful not to tear or mar the rubber.

2. On one side of the hub (usually left), the cone is locked against a collar on the axle (Fig. 4B). On the other side, place a 13mm cone wrench on the ball cone. Place a 17mm cone wrench

Fig. 2Bon the end nut (Fig. 3B). Loosen the end nut.

				3. Remove the end nut, wash-
			er, and ball cone from the axle
			(Fig. 4B).
				4. Slide the axle, with the
			other end nut, washer, and ball
			cone still attached, out of the hub.
				6. Gently insert a thin
			screwdriver blade between the
			shell shield (Fig. 5B) and bear-
Fig. 3B			ing seal (Fig. 6B). Pry off the
					shell shields from
	Axle
Collar					both sides of the hub.
					Do not attempt to pry
					off both shield and
					seal at the same time
					as you may damage
					the bearing seal.
				End nut	7. Gently pry off
					the bearing seals (Fig.
		Washer
					6B) from both sides of
	Ball cone
					the hub.
					8. If inspection
Fig. 4B
					shows it necessary,
			remove the other end nut. Hold
Shell shield
			the axle by the wrench flats
			(Fig. 7B) while turning the end
			nut with a 17mm cone wrench.
			Clean and inspect the parts
				1. Use solvent to completely
			remove all old grease and debris
			from the hub, axle, and axle
			parts.

2. Inspect the bearing run-

ning surfaces of both the ball cones and the ball cups (inside the hub). Replace any worn parts.

Note: If the ‘fixed’ ball cone is worn, the axle assembly (axle and ball cone) must be replaced.

Lubricate bearings and threads

1.Lubricate the threads on the axle with Wrench Force™ syn- thetic grease, or a similar product.

2.Place a bead of grease all the way around each ball cup, sufficient to hold the balls.

ASSEMBLY

1. Place eleven 3/16” balls in the ball cup on one side of the hub (Fig. 8B).

2.Place the bearing seal, with the lettered side facing out, into the ball cup.

3.Place the shell shield, with its sharp edges facing out, into the hub. The shell shield is a press fit, so must be tapped lightly to

fully seat. Lay a cone wrench over the shell shield and tap the wrench with a hammer (Fig. 9B) to protect the shield and ensure that it is flush with the shell.

4.Repeat Assembly steps 1-3 for the other side of the hub.

5.Tighten the end nut against the fixed ball cone (attached to axle). Hold the axle with an adjustable wrench on the

axle flats while turning the end nut with a 17mm cone wrench.

6.Insert the axle through the hub from either side.

7.Thread the ball cone, wash- er, and end nut onto the axle in that order. The serrated surface of the end nut faces out.

8.Hold the ball cone with a 13mm cone wrench and tighten the end nut with a 17mm cone

wrench.

9.Check the bearing adjust- ment by turning the axle with your fingers. The axle should spin smoothly without binding or feeling gritty. There should be no lateral play of the axle in the hub. Readjust the hub as necessary, and re-lock the end nut.

10.Install the external seals.

Make sure the seals properly seal against both the end nut and the hub shell. There should be a

smooth transition from seal to sealing surface. An improp- erly installed seal (Fig. 10B) will allow rapid contamina- tion of the bearings.

After completing assembly of the hub, check its function by spinning the axle with your fingers. It should rotate freely without irregular friction. A small amount of lateral play is acceptable if the play is eliminated when the wheel is installed with the quick release properly closed.

4 2003 Bontrager Service Manual