Monday, January 21, 2013

Today I want to show all of you one of my favorite tools, the Park BTS-1 bottom bracket, tapping and facing tool.  The reason it is such an important part of proper bike assembly is because it makes both sides of your bottom bracket perfectly parallel.  Anytime you have two barrings running in parallel, they need to be on the same plane or they will be working against etch other.  If this happens, they will either wear out prematurely or create drag, which no one wants.

Step One is to put your bike in a work stand, of course.  It's important to have a stable platform to work with.

Step Two is to identify the left and right sides of the tool which is designated by a LH and RH on the tap.  Now you would think that the left handed thread would go on the left side, but it is the opposite.

Step Three is to cover the cutting tool with fluid and flood the bottom bracket shell.  I like to use Cris King cutting oil.  Don't be worried about putting on too much, cutting dies are super expensive and the oil is cheep.  So lube it up good.

Step Four.  Carefully start threading the tap into the bottom bracket shell by a few threads.  Once both taps are started, turn them at the same time in the appropriate direction until you feel some resistance.  From this point on you should turn them no more then a half turn, then back a quarter to clear out the threads.  Remember to keep adding cutting fluid every full rotation or so.  Once you have the tool started a few full turns on both sides you can alternate from side to side.  Keep going until the tap is recessed into the shell.

Step Five.  Now we can start facing.  Pull the handle completely out of bottom bracket leaving the tap tool inside.  The tap will now act as a guide for the facing mill.  Install the facing mill cutter on the handle, then reinsert the handle into the taps.  Add fluid to the cutter, then apply steady pressure to the center of both handles and rotate only in a clockwise direction.  If you turn counter-clockwise it will dull the tool.  Only apply enough pressure to get a good 360 cut, if you press too hard you will gouge the shell.  A little chattering is ok, its only cosmetic and won't affect the function.  Repeat this step on the other side.


At first, you will just be removing paint.

 Almost there, just a little more.

Final Step.  Remove the tool from both sides of the frame at the same time, then clean off the tool and re-oil before storage.  Now you can clean out the frame and wipe it down. It's important to remove all remaining metal.  The final touch is to wipe a little grease on the new threads with you finger.

I hope you enjoyed seeing how this tool works, it's always fun for me to use it. 

1 comment:

  1. Yeah Buddy, my favorite tool as well! Right up there with a head tube chaser, even the finest of steeds needs a little chase.