Bottom Bracket Installation

Installating A Bottom Bracket on The 2001 Marin Palisades Trail Frame

The Marin frame did not come with a bottom bracket (BB) but I had a working used one on hand that was the right size for the frame and the right type that will fit the crankset that came with the Marin frame. The BB is a Shimano sealed cartridge model BB-UN73. It’s a square tapered. sized 68 x 113mm. The crank accepts a square tapered BB.Shimano Bottom Bracket  BBUN73

I installed a bottom bracket on the Marin Palisades Trail frame. To install or remove a bottom bracket from a frame, I use a special splined bottom bracket tool designed specifically for sealed cartridge style bottom brackets.

The tool is not expensive so I bought one when I got my first used mountain bike to work on. I think the tool cost me about $16.00 from Price Point. If you don’t want to buy the nut or to work on the bottom bracket yourself, you can always bring the frame and bottom bracket to your local bike shop and pay them to install it for you.

The bottom bracket is the square taper type as oppose to the newer splined type. In addition to the splined bottom bracket tool, I used a wrench and some anti-seize – not grease – to install the bottom bracket. Anti-seize “grease” still lubricate the parts during installation but also un-installing easier. Rubber gloves will keep your hands clean and make cleaning up easier and quicker.

Here how I installed the bottom bracket on the 2001 Marin Palisades Trail frame:

Step 1 – I cleaned the threads inside the bottom bracket shell of the frame.

Step 2 – I put a generous amount of anti-seize grease on the threads.

Step 3 – I then insert the bottom bracket cartridge into the bottom bracket shell from the right side or drive side – the side with the chain, chain rings and freewheel. The bottom bracket should have “L” and “‘R” with arrows printed on the label to help with orientation. The right side of the bottom bracket also has a lip.

Step 4 – I first lightly finger turn – to make sure I don’t cross the threads – the bottom bracket into the shell by turning counterclockwise.

Step 5 – When I can’t turn the bottom bracket with my fingers, I used the bottom bracket tool and wrench to continue turning the bottom bracket until the lip is pressed up firmly against the side of the bottom bracket shell.

Step 6 – I then thread the aluminum cup into the bottom bracket shell from the left side by turning the cup clockwise. Some BB comes with plastic cups. Again, I started tightening with my fingers first and then finished with the bottom bracket tool and wrench.

Step 7 – It’s recommended that the bottom bracket be tightened with a torque wrench to about 25-30 foot-pounds of pressure. I don’t have a torque wrench so I guess-imated. Don’t over tighten the cup. I usually check the bottom bracket on my bikes now and then just to make sure the cartridge is not working loose.Shimano BBUN73 Botton Bracket

Installing the bottom bracket is not difficult. The whole process took me about 15 minutes.

Next, I’m putting tubes and tires on the wheels and put the wheel on the frame.

Leave a Reply

Your email address will not be published. Required fields are marked *