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-   -   Just For Fun: Cup & Cone Bottom Bracket Fixed Cup Removal (https://www.bikeforums.net/bicycle-mechanics/683934-just-fun-cup-cone-bottom-bracket-fixed-cup-removal.html)

cal_gundert05 09-29-10 01:47 AM

Just For Fun: Cup & Cone Bottom Bracket Fixed Cup Removal
 
I've been looking at different tools and methods for removing the fixed cup of a cup and cone-style bottom bracket, and I think I've come up with another--it's the most complicated in design and execution, but it's something...

Let's assume that we're using a Park Tool Universal Crank Puller, and that out crank fixing bolts have a 8mm Allen head.

http://www.parktool.com/images/produ...9121_16807.jpg

1. Remove cranks and entire bottom bracket, except for the fixed cup, of course.

2. Re-mate non-drive side crank arm and bottom bracket spindle with one crank arm fixing bolt.

3. Screw second crank arm fixing bolt into other end of bottom bracket spindle.

4. Separate outer and inner studs of crank puller.

5. Place 8mm Allen head of smaller crank puller stud into the second crank arm fixing bolt, and slide split lockwasher (as Sheldon uses) over threads of stud until they rest against the flat 'head.

6. Slide non-drive side crank arm / bottom bracket spindle / small crank puller stud assembly through bottom bracket shell and through bottom bracket fixed cup (the small crank puller stud is 1/2" across, and Sheldon uses a 5/8" bolt, so it'll fit through the fixed cup).

7. Thread large crank puller stud into drive side crank arm.

8. Slide washer (also as Sheldon uses) over threads of small crank puller stud until it rests against fixed cup.

9. Thread large crank puller stud onto the small crank puller stud. Tighten crank puller studs by turning either (or both) crank arms clockwise, when viewed from the side of the bike on which that crank arm resides.

10. Once the crank puller is tight enough, turn entire assembly in appropriate direction, according to whether the fixed cup is right- or left-threaded. Prevent crank puller studs from unscrewing from one another by turning assembly in appropriate direction with one crank arm (which crank arm depends on whether the fixed cup is right- or left-threaded) while using the other crank arm to keep assembly properly aligned and keeping it in the same position relative to the other crank arm (don't rotate both crank arms in same direction, when viewed from the same side of the bike, or the crank puller studs may unscrew from one another and the assembly's grip on the fixed cup will weaken).

enigmagic 09-29-10 07:10 AM

That's interesting.

Might have to try this out at some point.

Hard to beat a fixed cup puller, though.

Kimmo 09-29-10 07:41 AM

http://i4.photobucket.com/albums/y11...lodinghead.gif

Reckon I could use a video.

Bekologist 09-29-10 08:37 AM

why not simply use a hammer and a blunted chisel thru the BB shell from the opposite side?


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