The coaster brake hub has the following parts from the drive side to
the brake arm side for Suntour and Bendix hubs. When you are trying to put
the hub back together this is the order you will need to follow.
Axle,
Axle nut
Washer
Lock nut (Thin)
Adjusting cone
1" ball bearing retainer with 1/4 inch balls
Driver with retaining ring, cog and some have dust caps
1 1/4" ball bearing retainer with 1/4 inch balls
Hub shell
Clutch ( Usually made of three parts, one being a spring)
Brake pads (Some have clutch pads and brake pads)
Stationary expander
1 1/4" ball bearing retainer with 1/4 inch balls
Dust cap
Brake arm Keyed (With chain stay clamp, nut and bolt)
Washer
Lock nut (Thick)
Washer
Axle nut
Tools needed:
Bench Vice, Can be a small 3' Jaw, clamp on vice, or a full size
bolted to the table vice.
Two cone wrenches to fit the lock nut and adjusting cone, (15 MM
and 9/16" or 17 MM are normal)
Magnet, Rod or Pen style is nice.
Grease (you get to choose the quality you like)
Shop rags to remove old grease.
Disassembly Procedure
The order parts go into the hub shell and the
orientation they go into the hub shell are important.
Flipping brake pads, bearing retainers, brake arm, hub shell, or
adjusting cone can be a really bad thing.
As you take parts off the axle, Lift them straight up, and over to a rag,
place them in the order you take them off and in the orientation
they were on the axle. Do not flip them over in your hand as you
put them down on the shop rag.
Place a shop rag beside a bench vice. Take off both sets of axle nuts and
washers and put them on a rag. One set (nut/washer) in one corner of the
rag and one set (nut/washer) on the other corner at the top of the shop
rag.
Hold the hub so the axle is pointed towards the ceiling and the floor with
the brake arm on the bottom side of the hub shell
Place the lock nut next to the brake arm in the jaws of the vice, (DO NOT
put the axle threads in the jaws)
Put the correct cone wrenches on the Lock Nut and the Adjusting
Cone. Hold the Adjusting Cone still as you loosen the Lock Nut. put your cone
wrenches down.
Use your fingers to unscrew the Lock Nut and place it beside the washer on
the rag.
Use your fingers to unscrew the Adjusting Cone and place it beside the Lock
Nut on the rag, Orientation is important.
Use the magnetic pen to remove the 1" ball bearing retainer and place it
beside the Adjusting Cone on the rag. Orientation is important.
Use your fingers to twist the Driver out of the hub shell, place it beside
the Ball Bearing Retainer on the rag. It may fall on its side.
Use the magnetic pen to remove the 1 1/4" ball bearing retainer and place
it beside the Driver on the rag. Orientation is important.
In the next step the brake pads will fall out the bottom of the hub shell.
If you wrap one finger and a thumb below the bottom flange of the hub shell to
catch the brake pads as they fall out.
Grasp the hub shell and lift it off the axle. Place it on the rag beside
the 1 1/4" ball bearing retainer. Orientation is important.
Pick the brake pad off the floor and place them on the rag beside the
hub shell. ( I knew you would drop them the first time, you will get better at
catching them)
Remove the Clutch and place it on the rag beside the Brake Pads.
Orientation is important, and the Suntour Clutch likes to fall over.
If you have a digital camera take a photo of the parts and their
orientation before you clean.
This is all that you need to remove to rebuild a hub.
If you want to disassemble the rest do the next list, if not
skip and go to Cleaning
Grasp the Brake Arm and twist it counter clock wise.
Loosen the bench vice jaws from the lock nut.
Use your fingers to remove the lock nut, place it on the rag next to the
second set of axle (nut/washer)
Remove the Brake arm and place it on the rag beside the Lock Nut.
Orientation is important.
Remove Dust Cap from Stationary Expander, and place it beside Brake Arm,
Orientation is important.
Using your fingers unscrew the Stationary Expander
Push on both sides of the 1 1/4" ball bearing retainer to pop it off the
Stationary Expander. Place the Stationary Expander beside the Dust
Cap, Orientation is important.
Place the 1 1/4" ball bearing retainer beside the Stationary
Expander. Orientation is important.
If you have a digital camera take a photo of the parts and their
orientation before you clean.
Cleaning
I prefer to use a rag and no cleaners. If you use a green color bio
degreaser it will work a little better if it is warmed up to 120 F. If you use a
Yellow citrus degreaser, use gloves and ventilation. The green stuff
is a strong detergent and the yellow is an aromatic citrus acid. If I do not use
a solvent then I do not have to remove the solvent from the part with a second
compound. Detergents remover the citrus and water removes the detergents
from your parts.
I like to push out all the bearings out of the retainers and
replace them with new grade 300 balls. Grade 25 Campagnolo quality
bearings would be overkill.
I wipe all the grease I can get off the bearing cups/ cones and the threads
of the clutch/ driver.
There are also new parts washers that use warm detergent if you like
to use big tools. Wash with water after to remove the detergent.
Place all the parts back on the shop rag in the correct order and
orientation.
Reassembly
If you did not remove the brake arm from the axle then skip the
next nine lines.
In the correct orientation place the 1 1/4" ball bearing retainer on the
Stationary Expander
In the correct orientation screw the Stationary Expander about 1 1/2"
onto the Axle
In the correct orientation place the Dust Cap on the Stationary Expander
In the correct orientation place the Brake Arm on the Stationary
Expander
Place the Washer against the Brake Arm
Screw the Lock Nut on the axle up to the washer, Keep the assembly loose so
you can adjust it.
I use the 1" Ball Bearing Retainer as a measuring tool to determine where
the lock nut is supposed to be.
I hold the assembly in one hand and twist the Axle in or out of the rest of
the loose assembly until one inch is sticking out from the Lock Nut.
Check that the Stationary expander is snug against the lock nut.
Place the Lock nut into the jaws of the bench vice.
Grasp the Brake arm and tighten it clockwise as hard as you hand will
allow. No hammering needed.
In the correct orientation place the Clutch on the Axle and onto the
Stationary Expander, Twist the clutch until it locks into the Stationary
Expander.
Look at the inside of the brake pads, Bendix pads will have one end
smooth and one end with dents in the surface finish. The smooth sides of the
brake pads push against the stationary expanders smooth ramps. on the other
end of the brake pad will be little dent marks from the rough edges of the
Clutch ramps.
Grease up the inside of the Hub Shell and the bearing race cups at the end
of the Hub Shell. The more the merrier
The following is a strange skill I learned form a good teacher. Place
the brake pads between the ears of the Stationary Expander. Pinch the pads as
far to the bottom of them as you can. Slide the Hub Shell down over the pads. Do
not release your fingers and push the shell down, Let the Hub Shell push your
fingers out of the way as you slowly push it down. Twist the Hub Shell to make
sure it is seated correctly over the lower bearings. No bearing should be
visible from the outside.
Install the Upper 1 1/4 bearing retainer, Orientation is important.
Grease the Driver cup and cone surfaces. Install the Driver into
the Hub Shell, twist it into the Clutch.
Install the 1" Ball Bearing Retainer into the Driver.
Install the Cone, Orientation is important.
Install the Lock Nut
Using the appropriate Cone Wrenches adjust the cone and lock it into
place.
Check the hub adjustment to see if it is too tight or too loose.
We have been holding races with our students to Disassemble, name all the
parts, and reassemble a coaster brake hub. These were hubs cleaned of all
their grease and just for such races. The top time so far is 2:36 Two minutes
thirty six seconds. Pinching the brake pads is a real trick.
Christopher Wallace
BicycleEducation@aol.com