[TheThinkTank] Coaster Brake Hub Overhaul

[BovineOaks at aol.com]

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 at aol.com
 




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