Stuck removing bottom bracket

[EthanT]

Hi,

After some help please. I think there’s something wrong with the bearings on my partners bike so I am trying to take the bottom bracket off to replace or look at the bearings to have a look. There is a lot of wobble from the pedals that I can’t tighten so have taken off the pedals but can’t workout how to get the last bit off. There’s a tiny lip on what I assume is a giant nut to unscrew, but I can’t get any decent grip on it as it’s so small and slightly angled.

Any ideas what to do?

Thanks

[ReapThaWhirlwind]

You can take it to your local bike shop and ask them to remove the bottom bracket.

Typically, they'll do it for free, or just a few dollars.

That is an odd sealed bottom bracket. Normally, the sealed bottom brackets have a special tool to remove them. It's best to use an impact wrench to remove old ones as to get the best direct torque to not damage the threads in the bike or strip out the spline inlets of the sealed cartridge.

https://www.danscomp.com/pedros-splined-bottom-bracket-socket-tool-for-shimano-isis-drive-splined-bb-6460201/p324759

However, it looks like yours has a cup n cone outlet. There's a special spanner wrench to remove them.

In fact, there's two special ones.

Park Tool HCW-4 & Park Tool HCW-11

If there was wobble in the pedals that typically means that the bottom bracket needs to be tightened. Best to take everything out, re-grease it, then install the cup n cone. If your bike as a sealed cartridge, then it's best to replace the entire thing. Measure the bottom bracket shell of the bike and the spine from end-to-end to know which size you need. Your bike likely has a 68mm bottom bracket shell. And I'd be willing to bet that spindle is 125mm/124.5mm. So you would need a 68x124.5 sealed bottom bracket. Do check the measurements though to be sure. The other size bottom bracket shell is 73mm. Don't get the wrong one. Be sure.

Another really important thing to note is that the threads on bottom brackets are reversed from the sides they are on.

The right side (drive side) has a left-hand thread. Meaning, it tightens counter-clockwise and loosens clockwise.

The left side (non-drive side) has a right-hand thread. Meaning, it tightens clockwise, and loosens counter-clockwise.

Pedals have different thread directions too—but they are the same as the side they are on.

[Jesper]

(10-17-2022, 03:25 PM)ReapThaWhirlwind Wrote:  Another really important thing to note is that the threads on bottom brackets are reversed from the sides they are on.

The right side (drive side) has a left-hand thread. Meaning, it tightens counter-clockwise and loosens clockwise.

The left side (non-drive side) has a right-hand thread. Meaning, it tightens clockwise, and loosens counter-clockwise.

Only certain bottom brackets have reverse threads on the drive side. Most newer BB's are like stated above, but beware on certain classic frames (ALSO NEW FRAMES! e.g. Colnago) or you will destroy your BB assy, BB shell, and/or both. Italian (still in use), and French BB's (generally only on frames pre-1990 or so) are NOT REVERSE/LEFT-HAND THREADED. Both sides are right hand threads on Italian and French BB's.