Thursday, July 26, 2012

Servicing the Earles fork

Today, let's focus on servicing the Earles fork.

I always try to keep a new set of tapered bearing and sleeves on hand incase a customer bike comes in with worn old style ball bearings, or even worn tapered bearings.  It is too dangerous to ride with bad bearings and I will always recommend replacing them as soon as possible with new bearings.  Tapered bearings far outperform the original 23-ball-race factory bearings.

Tear down on this R60/2 showed me that the head bearings need to be replaced. They had a notch at the center position. You can check this when the front wheel is off the ground and the steering damper all the way loose.  Move the steering left and right through its travel and if you feel a "notch" or drag at the center position, the bearings are probably shot.  Later in this article, I will also tell you how to determine if your steering bearings are too tight or loose.

State of affairs.

Support the front of the bike on jackstands or blocks of wood.  I normally connect a safety strap to a ceiling joist when I am jacking a bike. Remove the front wheel, brake and set aside.

Remove the swing arm axle nut and unscrew the bolt.  The nut serves as a lock nut.  The bolt is threaded into the fork and tensions the bearing.

Earles Fork Spacers are bike-specific and side-specific.  Some don't use one spacer, or both are on one side. Note the position of the spacer washer(s), if any.


Earles swing arm pivot bearings. These are lubed and looking pretty decent.
Left side looking good too.

Clean bearing races of old grease. 
Outer races for Earles fork swing arm bearings are worn (showing bearing shadows) but not detented.
The other side looks ok too.

Apply new grease. (Wheel bearing grease.)
Fresh grease.
Seals look good.
Before repacking with grease, I did spin the bearings dry to get a feel if they were smooth.  They were.
State of affairs.  
Removing the Earles fork top plate.
Someone had arranged the harness through the fork square so I had to remove the wiring harness from the ignition board in order to remove the headlamp nacelle.  A bit of a delay, but it gave me time to clean and seat the bulbs in the green and red sockets.
Upper lower race. Rusted and detented.  There was only a little dried grease here.  These may have never been serviced in 50 years. 

Lower upper race looks like original factory grease. Race is dented.
Lower inner race.
Upper top race is detented and dry as a bone.  Pitted.
Posted by Picasa