This simple how-to article is specifically for the Ultegra line of rear derailleur tension & guide pulleys, aka jockey wheels. In this specific case, the RD-6800 guide pulleys are identical to the 6870 guide pulleys so for sake of simplicity, we will call them RD-68xx. This article does NOT apply to the Dura Ace RD-9000/9070 tension & guide pulleys since the RD-90xx pulleys use sealed bearings.
While cleaning my bike the other day, I noticed that the upper pulley had considerable resistance so that it was hard to turn by hand. Since my RD-6870 only has a couple thousand miles, it seemed unlikely that the pulley/ceramic bushing was worn out.
I had already removed the rear wheel so I took a brand new 3mm allen wrench and quickly removed the upper jockey wheel. Note: using a NEW allen wrench will help prevent stripping of this screw. Pinching the dust caps together ensured that I wouldn’t lose any bits and pieces. Placing the jockey wheel on the workbench I stripped it down completely.
HOW IT WORKS
The upper jockey wheel is located in what is probably the filthiest location on the bicycle. It tends to collect all of the gritty chain sludge and easily attracts sand and gravel thrown up by the front wheel. Go out to your garage, take a look and see if you agree.
In the attached pictures, you can see a groove cut into the upper guide pulley. This is where the rubber dust seal is pressed into. When the metal dust cap is placed over the pulley, the inside of the dust cap comes into contact with the rubber dust seal stopping all grit, dirt and other contamination from getting into the ceramic bushing. Sure it keeps the bearing clean, but it also causes considerable drag.
Removing these 2 rubber seals will allow the upper jockey wheel to spin much easier, freeing up some watts that you can transfer to the pedals.
Since the RD-68xx jockey wheels use a ceramic bushing as its bearing, a little dab of light grease such as TPS SBG-32 will do perfectly to ensure that the guide pulley spins freely.
If you take care of your drivetrain, cleaning the chain after each ride, wiping the grit and sludge off the guide pulleys, wipe down the chain rings and the cassette, you should have no guide pulley issues after removing the rubber seals.
I have always enjoyed bicycling and, through a series of coincidences, became a Bicycle Industry Consultant and Product Tester. I test prototype products for companies and have published only off the shelf production products on biketestreviews.com.