The Gnarliest Bearing Swap

The first set of bearings turned out to be the nastiest to pull. This was in part because it was a pair of bearings pressed in together, with only partial access to press them out from behind, and no access to the outer race at all. The other reason they were so bad was because I hadn't figured things out by screwing them up yet.

I didn't consider using a blind drift, because I didn't think I could get purchase on the gap between the bearings because they were pressed together so tightly, and I didn't have the right size drift anyway.

Eventually I went old school and smashed the remaining bearing from behind with a hammer. Before that I had bodged together a few different parts from different bearing pullers and pulled on the two bearings together. The outside bearing popped but the remaining bearing had angled itself. Okay, actually I managed to pull it at a less than optimal angle and it had jammed itself inside its aluminum-lined hole in the carbon fibre seat stay. This was not ideal.

More bashing ensued until the inside bearing bits were spat out and only the outer bearing race, still wedged at a nauseating angle, remained. I knew I had to be careful here, because destroying the aluminum bearing seat would trash the entire seat stay. Some hammer and chisel work got part of the steel race out but another chunk remained wedged. I was quite sure I was fucked at this point but I pressed on and, to my amazement, got the rest out.

This whole process, only to remove two bearings, took several hours. I didn't have the perfect tools and there was no guide to work from, but that was kind of the point. I wanted to figure it out on my own. But I was spent and it would be two and a half months before I was ready to tackle the rest of the task.

Why was I putting myself through this? I'd had some annoying and difficult to diagnose play in the rear end of my Norco Sight VLT. I couldn't notice it when I was riding, although it still may have been working against me, but when I grabbed a handful of frame and yanked the wheel side to side, it was incredibly obvious. Swapping all the bearings seemed like a good place to start, but I had no idea how many there would be. I was also surprised to learn about this particular parallel pair that didn't allow access to the outer bearing race from behind. No matter, the next set would have to be easier.

This set was also in the seat stay but at the top, where it attached to the rocker link. These ones went in from each side and there was a lip that separated them, so there was no getting them out without a blind drift. I actually have three of those but not one in the correct size, at least not without modification.

The drift works by driving a shaft down the middle of a collet which is split into four segments. When the shaft progresses further down the collet, the four segments splay outward like a blooming tulip. The expanded lip can then fill an inner bearing race and grab it from behind, even in the case of paired bearings. My kit has a 10mm, 8mm and 15mm blind drifts but I needed a 12. I reasoned that the 10mm version could work if the shaft was a little longer. I rubbed my chin a little, thinking the idea was futile and then had a glimmer of hope. Like Ferrentino, I've got tools as old as mountain biking, going back to the days when the ball bearings in hubs, bottom brackets and headsets weren't even caged. I thought the odds were good I'd find some loose balls in my old kit. If I happened to have one the right size, maybe 1/4", It might extend the shaft enough for my 10mm drift to blossom into a 12.

Without too much digging I found one single bearing that looked about right. I pulled apart the tool, dropped the ball in and, at first at least, it seemed to do the trick. I got everything set up and expanded the drift in place and, unbelieveably, it grabbed. This isn't as simple as just yanking it out though. I needed something to protect the carbon fibre from the edges of the sleeve for the initial pull so, again taking a cue from Señor Ferrentino, I slid a 15mm Park cone wrench between the sleeve and the frame so I could give it a good yank. Once it broke free of the the seat, I needed to take everything apart and remove the cone wrench so the bearing could push all the way out. This was time consuming but effective.

Lately I've been getting immense satisfaction out of fixing and building things, both poorly, but nothing makes me feel as chuffed as either modifying or building a tool to complete a task. This felt monumental.

There were many more bearings to go however so it was time to get back at it. Now that I had my blind drift procedure settled I was mostly dialed in. I came across a few bearings that were still perfect (quite shocking all things considered) and I left them in place. The main bearings, the only spot on the bike, with larger 6901 bearings and without doubled bearings, were a snap. I have now swapped almost all of the bearings and I'm just about ready to put things back together.

And I found the problem it seems. I discovered that the bearing seat at the non drive Horst Link is too large and those bearings just fell out. As a result, the stay moves independently in certain circumstances, while the bearings stay where they are. I'll need a new seat stay but I'll probably check with Norco and cement a couple in there with JB Weld until the replacement arrives. Now I've just got to put it all back together.

This was a significant challenge for my ADHD-challenged brain but having accomplished it (mostly) successfully feels pretty okay. It also makes the prospect of taking on another daunting task much more palatable.

I learned a lot about the bike as well. The bearings had remained in remarkably good shape after three hard years of riding and the tolerances, with the exception of the one seat at the non-drive side Horst Link, were excellent. I'm also impressed with Norco's effort to double up all the bearings and this has seemed extend their life significantly. The choice of Enduro Max bearings also seems to be making a big difference too. A full set from Enduro will set you back around 129 USD - but couldn't find the exact kit, either on Enduro's site or from Norco. I did find a pretty interesting looking blind drift kit off Amazon for 48 CAD as well and this tool from Bearing Pro Tools looks pretty cool as well.

How Not To

In case this isn't clear, my DIY articles aren't meant to be how-tos per se. My hope is that my bungling through some task will help you avoid the mistakes I make and inspire you to try something you think is above your pay grade.

The next thing you know, you'll be giving yourself a raise.