(MkIII) Bottom Bracket / Drilling Install

[Speedub.Nate]

This post is one in a series of twelve posts depcting the build of my Hollowpoint MkIII. Link to MkIII / Speedhub bike build post.

My no nonsense, quiet, and easy to remove bottom bracket install. Why? With all the complaints of loose bottom brackets, damaged threads and squeeks I hear about, this is my answer. And even after a couple of years in place, removal remains as smooth as butter. It's not a lot of extra hassle. First things first: Drill a drain hole in that bottom bracket shell. I know this is often debated, but even living in mostly dry northern California I'm constantly amazed how much sludge spills out of my undrilled shells. Use a center punch to mark the drain point and to prevent the drill bit from walking all over the nice paint.

With a 1/8" drill bit, do the deed.

Check for a lip inside. If it's there, take it down. I use a Dremel 9903 carbide-tipped bit, the same one I use for drilling out cable stops.

Use a hooked tool, scribe or razor blade to clean any gunk out of the shell's threads left behind from a previous installation.

I always like to do a test fit, to ensure the threads are in good shape. Just a couple drops of oil on the cartridge...

...and install both sides hand tight to verify there is no cross-threading. If the threads are buggered and this step meets excessive resistance, have a shop chase them.

Wipe the threads down and apply a finger full of Permatex Anti-Sieze lubricant. You'll be able to find this, or something similar, at most hardware and automotive stores.

Wrap two turns of teflon pipe thread tape to each cartridge adapter or cup. Pay attention to the direction so that the "tail" of the tape is facing away from the direction of rotation.

It's going to turn in with more resistance than during the test fit, so take your time, make sure it's straight, and start it by hand until you're positive you haven't cross-threaded anything.

Here's a handy trick: If you have a hollow spindle, you can use a rear wheel QR skewer to hold the adapter in place for final tightening (this work even better for sticky removals). You'll need an appropriately sized socket to drive the adapter because the square hole your ratchet normally engages is taken up by the skewer.

Torque appropriately (50 foot-pounds for Shimano cartridges, check your installation sheet for others).

	Index of MkIII Build Posts
MAIN: MkIII / Speedhub Build Pics Iron Horse MkIII Naked Frame (March 2005) Hollowpoint Speedhub Build Pictures (April 2003) Cane Creek AD-12 Air Chamber Volume Adjustment White Brothers 2006 Technology	White Brothers DT 1.2 Fork Porn Stripping Anodization Bottom Bracket Drain Hole Drilling & Installation Drilling Out Cable Stops (Full Length Cable Run) Dremel Cut & Prep of Cable & Housing	Hopey Steering Damper Installation Stripping & Polishing an Aluminum Frame Homemade Headset Removal & Installation Tools Star Fangled Nut Removal (Drilling out the Star Nut)

[Mr.P]

Thanks bro.

I probably would not attempt to drill my frame, but after viewing your instructions I now have no hesitation.

Thanks!

Mr. P

[Speedub.Nate]

Originally Posted by Mr.P

I probably would not attempt to drill my frame, but after viewing your instructions I now have no hesitation.

Just as a point of reference, I didn't drill out the BB on my last frame (the Hollowpoint), and the rust-colored, gooey sludge that poured from that shell when I cracked open the bottom bracket was amazing.

Considering that I didn't even ride that bike in the rain much (I use my hardtail primarily as my winter bike), I felt it was substantial water accumulation for 2+ years of use.

[Mr.P]

Originally Posted by Speedub.Nate

Just as a point of reference, I didn't drill out the BB on my last frame (the Hollowpoint), and the rust-colored, gooey sludge that poured from that shell when I cracked open the bottom bracket was amazing.

Considering that I didn't even ride that bike in the rain much (I use my hardtail primarily as my winter bike), I felt it was substantial water accumulation for 2+ years of use.

I hear ya. I ride the same conditions. I think most of my water came in when I washed the bike. No more of that. I bought a washing mit - no more hose.

Mr P

[SHIVER ME TIMBERS]

Originally Posted by Speedub.Nate

Considering that I didn't even ride that bike in the rain much (I use my hardtail primarily as my winter bike), I felt it was substantial water accumulation for 2+ years of use.

um poor maintenance...should do it every 4 to 6 months...take out clean and regrease

[clads01]

Is there any way this can be done safely with the BB and cranks still in place? I.e., how much clearance is there between the inside of the frame BB shell and the exterior surface of the BB?

[Speedub.Nate]

Likely. BB shells are typically pretty thick... easily 1/8", probably closer to 3/16.

Just use a drill stop or mark your bit with a piece of tape, and proceed carefully.

Drill the center and you'll avoid any threads.

The shell of the bottom bracket cartridge doesn't sit flush against the inner wall of the BB cartridge, so you've got a little gap for some error.

[arnijr]

Beautiful build log and lots of helpful tips and pictures, love it.
I have one question about the BB install, even if this thread is old. Why use teflon pipe thread tape? Not to make it watertight I'm sure, what's the advantage?

Thanks,

Arni

[logbiter]

Originally Posted by arnijr

Beautiful build log and lots of helpful tips and pictures, love it.
I have one question about the BB install, even if this thread is old. Why use teflon pipe thread tape? Not to make it watertight I'm sure, what's the advantage?

Thanks,

Arni

to help keep it from creaking... common practice for steel BB cups and alu BB shells (or any cup/shell interface where disimilar metals).
that's my excuse, and I'm sticking to it ... naw, this is just my understanding of it, and it's worked for me since I couldn't get my BB to stop creaking on my first alu framed bike, that's what the mechanic at the LBS suggested.

[arnijr]

Great, thanks for the reply. Hadn't given the dissimilar metals thought but now that I think about it that makes sense. I'm having the LBS install my BB and HS right now, but that's mostly because it's a new frame and it needed chasing and facing. Might just take the BB out again and use these instructions.

[fallinfast3x]

Originally Posted by clads01

Is there any way this can be done safely with the BB and cranks still in place? I.e., how much clearance is there between the inside of the frame BB shell and the exterior surface of the BB?

I'd think twice before doing this. Look at the photos of the inside after drilling. Is it possible that all that metal could end up in your bearings? I've never taken my BB apart so I don't really know. But its my guess that the bearings are not completely sealed.

[Speedub.Nate]

Originally Posted by clads01

Is there any way this can be done safely with the BB and cranks still in place?

Originally Posted by fallinfast3x

I'd think twice before doing this. Look at the photos of the inside after drilling. Is it possible that all that metal could end up in your bearings?

Just as an aside, I drilled out a new frame a couple of weeks back, but started by dipping the entire length of the drill bit into a tub of grease.

The end result was very clean, and I'd swear no shavings made it into the shell.

But afterwards, when I was threading in the EBB, it sounded kind of crunchy, as if the threads picked something up when they passed over the new hole. So I'm a little iffy on the greased bit technique being 100%. Maybe 99%, but not 100%.

On top of that, a steady arm is required, because you don't want to punch through the wall of the shell and cut a groove into your spindle, if your using outboard bearing cranks.

For anyone using a cartridge bearing setup (I am), drilling with the cranks still installed won't be a problem. The bearings are isolated, and it wouldn't matter if the drill etched a groove in the cartridge.

[nnn]

I use metal-bristle brushes (BBQ cleaning brushes) to clean out BB threads, then wipe with a thick cloth. Could also use compressed air, but if you take care no metal bits will remain and in any case it's more likely to get dirt and muck inside there without a hole which is about as bad as metal shavings..