How do I safely remove the BB90 bearings from a Trek SC 9? Is there a special tool or should I just have at it with a hammer and screw driver?
take it to a Trek dealer. 
What’s the fun in that?
Seriously though - it’s a specialized process? Must be a Trek deal around here somewhere if necessary.
consult your manual…
To remove the bottom bracket bearings
The Speed Concept bottom bracket bearing system is designed to be a slip fit. However,
after the first installation some bearings might be tight. If the bearings do not easily come
out by hand, you may use the following method to remove them.
- Slide the crank axle into the bearing so that the bearing is over the non-drive side of the
axle, about 1 inch (25 mm) from the non-drive end. - Gently rock the axle while you pull the axle out.
You can use a hammer and screw driver, but you will ruin the bearings.
Get a headset press it wiil press out the bearing and press in the bearings. I think I saw a bearing remover (basic type tool) on the Park Tool site or maybe it was Performance?
Good luck.
Thanks - hammer it is!!!
You can use a hammer and screw driver, but you will ruin the bearings.
I was kidding about the hammer and screw driver, although it turned out not to be too far off from the “proper” method.
If you don’t want to risk damaging the bearings then you can take a fine (32 pitch) hacksaw blade and make two small cuts either side undert the BB, about 5 and 7 o’clock as you look from the side. That will reduce the tension on the cups ad they should slide right out unharmed.
The park tool is your best bet if you want to do it properly. But if you want an adventure then you could do what I did…
Get a nice and soft wooden dowel of about an inch in diameter. Mine was made of fairly soft wood that I had lying around from an old broken chair. Inserted it into one side of the BB and gently tapped it with a rubber malet. I made sure my taps were light and done all around (internally) of the bearing. Took me about 30 seconds or so and voila - the bearing cartridge popped out.
Disclaimer: What I did is not what I would recommend. It is simply what I did - but it worked. :>)
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enduro might make a tool for bb90, I know there is one for bb30 that is really nice.
Either way, you don’t want to hammer it out, you want to press it out slowly.
The Park BBT-90.3 tool works great. Only took a couple of minutes to drive the SRAM Red bearings out and replace them.
Web site with PDF’s, showing the installation of the different BB
http://www.trekbikes.com/pdf/2011/service_manuals/Trek_2011_Speed_Concept_Service_Manual.pdf
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Did you use a headset press for the new bearings? I don’t mind dropping $30 on the BBT-90.3 but the press is another $75. Would probably cost me $30 total to have a shop do it.
The Park BBT-90.3 tool works great. Only took a couple of minutes to drive the SRAM Red bearings out and replace them.
Yes, I already had a bearing press for hubs and various other applications. The Park tool comes with the correct bushings to press in the new bearings. It was all pretty easy.
The non-drive side BB bearing gave up at 1500 miles; I got a new bearing set from my dealer.