Downhill Bike Service - Pivot Bearings and Bottom Bracket

This year - I've had the opportunity to perform a couple iterations of a rear suspension pivot bearing service on a 2016 Transition TR 500.  Today I also pulled the bottom bracket bearings since I haven't checked them all year.  The process is rather simple, so this is not intended to be a 'How To' article. My purpose is to provide some actual photographs to supplement the schematics you may be using, outline the tools and parts you will need, and share some opinions and recommendations.

Here is what you'll need before starting:

Parts:  Bearing 6804 RS (2 each), Bearing 6901 RS (6 each), BB Repair Kit: Wheels MFG 24mm ABEC-3 BB Repair Pack, grease, blue threadlocker (Loctite), and other supplies you might consume while disassembling and cleaning your bike.

Tools:  Sealed Bearing Extractors for 10mm and 20mm ID Bearings, PRESS 1 Handle and Rod Assembly, and a bearing drift set.  All available from Wheels Manufacturing, Inc.  Other small tools to manipulate the extractors and press as necessary 

At this point I'll share some observations. In my experience - most downhill bikes ridden by the typical amateur racer can survive a full season without a bearing service. This includes bikes with very large bearings (i.e. the Canfield Jedi) as well as bikes with smaller bearings (i.e. the Specialized Demo 8). For some reason, our experience with the TR500 has been quite different. It has not been uncommon for us to experience severe bearing 'creaking' after the first muddy race weekend. I won't speculate the cause for that, but we have no different results whether we use power washers or standard water pressure.  Here are some images of what we are finding when disassembling the bike.

Somehow, under conditions typical for racing downhill in the Eastern US, using normal water pressure for routine cleaning, water is making it past both of the bearing seals and actually staining the inside of the suspension linkage! These are '2RS' bearing with seals on both sides. Six of the eight bearings for the rear suspension were corroded, and 4 could not be rotated by hand - siezed. There is rust on the contact surface of the pivot hardware, the frame, and the bearings. During the install we used a light coating of grease on all of these surfaces. (Note: take care doing this that you do not end up with grease in the threads during reassembly). There must be something that can be done about this.

These are new bearings. There is a very light coat of grease even for new bearings. Given the application for these bearings is a downhill bike and not full rotation, continuous spinning...we are going to try adding additional grease, before reinstalling the seals and putting the bearings in the frame. We'll try this, in hopes we can make it through one washing without the dreaded creaking afterwards.

I hope this article gives you the confidence you need to tackle this job yourself - or the confidence in use to do it for you!