Installing press fit BB anti-seize, pipe dope, grease, or...?

RetroGrouch

Active Member
Short answer? Install the BB in accordance with the frame manufacturer's instructions. If those don't exist, follow the BB manufacturer's instructions. For example, Wheels Manufacturing specifies grease for steel and aluminum frames, PTFE/teflon for carbon frames, and anti-sieze for titanium frames. They also specifically state that retaining compounds or epoxies void their warranty. You also get the following disclaimer in their instructions. "Due to the wide variety of frame manufacturers, Wheels Manufacturing cannot guarantee compatibility with all frames. Please consult with your specific frame manufacturer before installation."

Grease functions well enough as anti-seize and will keep out water but a poor press fit will eventually move grease out of the joint as parts move. Grease masks the noise if/when parts move until the grease is gone. That same relative movement wears out the BB shell making for a looser press fit over time and more noise. This is why I recommend bearing retaining compound when possible.

Press fit BBs are great until they aren't. The PF failure rate (of the press fit, not the bearing itself) is probably pretty low, maybe 10% or less if I had to pull a number out of thin air. Unfortunately, you are screwed if you are in that 10%. My limited personal experience resulted in creaking after a few hundred miles even though I pressed the BB into a greased BB92 shell of an aluminum frame using a threaded rod tool with mandrels sized to press on the outer bearing race. They very same cups, pressed into the same frame after cleaning, with a bearing retaining compound, seem to be silent after a couple hundred more miles. Only time and miles will tell if my fix is permanent. If the green stuff fails, I will install a thread-together BB which is available for 24mm spindle cranksets. 30mm crankset users do not have that option. Yes, Wheels MFG may "void" my warranty, Magnuson-Moss warranty act or not, but bearings are cheap enough. I understand why they don't want the user making it more difficult to remove their BB. The cups are fairly thin wall aluminum. Green Loctite can require some heat to remove without lots of additional force. Epoxy would be even worse.

The lack of good tolerance specifications for the BB itself and reaming a BB86/92 bottom bracket shell is probably the root cause of most of these problems. If I look in my Machinery's Handbook 22nd Edition, and pick an ANSI FN1 fit (light drive fit), I see a range of interference between .0004 and .0014 inch (range of .0010) for a shaft size 1.614 in (41mm). If I had to guess, I would say that is a huge range from "tap it in with a rubber mallet" to "hammering the crap out of it". I would pick tighter tolerances after determining what works for the worst case clydesdale hammering up a 20% slope with a 22T chainring and a fully loaded bikepacking rig for 5000 miles. Is there any chance the overseas manufacturers did similar homework when determining press fit tolerances?

Here is a tolerance for a BB92 shell from FSA courtesy of QBP. https://qbp.com/diagrams/TechInfo/FSA/externalbbfitchart.pdf
41mm -.010/-.040 or 40.96 to 40.99 which is a range of ~.0012 inches. That BB shell tolerance range alone is more than the range of an FN1 fit. Add in tolerances on the BB cups and press fits get ugly quickly. Tighten up the tolerances if you want more reliable press fits.

Spend a couple hours reading the frame building forum on mtbr.com for lots of real world experience discussing the issue along with a couple unhinged rants dismissing those with creaking.

edit: math error
 
Last edited:

Tim

aka sptimmy43
Short answer? Install the BB in accordance with the frame manufacturer's instructions. If those don't exist, follow the BB manufacturer's instructions. For example, Wheels Manufacturing specifies grease for steel and aluminum frames, PTFE/teflon for carbon frames, and anti-sieze for titanium frames. They also specifically state that retaining compounds or epoxies void their warranty. You also get the following disclaimer in their instructions. "Due to the wide variety of frame manufacturers, Wheels Manufacturing cannot guarantee compatibility with all frames. Please consult with your specific frame manufacturer before installation."

Grease functions well enough as anti-seize and will keep out water but a poor press fit will eventually move grease out of the joint as parts move. Grease masks the noise if/when parts move until the grease is gone. That same relative movement wears out the BB shell making for a looser press fit over time and more noise. This is why I recommend bearing retaining compound when possible.

Press fit BBs are great until they aren't. The PF failure rate (of the press fit, not the bearing itself) is probably pretty low, maybe 10% or less if I had to pull a number out of thin air. Unfortunately, you are screwed if you are in that 10%. My limited personal experience resulted in creaking after a few hundred miles even though I pressed the BB into a greased BB92 shell of an aluminum frame using a threaded rod tool with mandrels sized to press on the outer bearing race. They very same cups, pressed into the same frame after cleaning, with a bearing retaining compound, seem to be silent after a couple hundred more miles. Only time and miles will tell if my fix is permanent. If the green stuff fails, I will install a thread-together BB which is available for 24mm spindle cranksets. 30mm crankset users do not have that option. Yes, Wheels MFG may "void" my warranty, Magnuson-Moss warranty act or not, but bearings are cheap enough. I understand why they don't want the user making it more difficult to remove their BB. The cups are fairly thin wall aluminum. Green Loctite can require some heat to remove without lots of additional force. Epoxy would be even worse.

The lack of good tolerance specifications for the BB itself and reaming a BB86/92 bottom bracket shell is probably the root cause of most of these problems. If I look in my Machinery's Handbook 22nd Edition, and pick an ANSI FN1 fit (light drive fit), I see a range of interference between .0004 and .0014 inch (range of .0010) for a shaft size 1.614 in (41mm). If I had to guess, I would say that is a huge range from "tap it in with a rubber mallet" to "hammering the crap out of it". I would pick tighter tolerances after determining what works for the worst case clydesdale hammering up a 20% slope with a 22T chainring and a fully loaded bikepacking rig for 5000 miles. Is there any chance the overseas manufacturers did similar homework when determining press fit tolerances?

Here is a tolerance for a BB92 shell from FSA courtesy of QBP. https://qbp.com/diagrams/TechInfo/FSA/externalbbfitchart.pdf
41mm -.010/-.040 or 40.96 to 40.99 which is a range of ~.0012 inches. That BB shell tolerance range alone is more than the range of an FN1 fit. Add in tolerances on the BB cups and press fits get ugly quickly. Tighten up the tolerances if you want more reliable press fits.

Spend a couple hours reading the frame building forum on mtbr.com for lots of real world experience discussing the issue along with a couple unhinged rants dismissing those with creaking.

edit: math error

Thanks for the reply! I always appreciate knowing why something is the way it is and you definitely provided a lot of food for thought.
 

Ian F

Well-Known Member
So far, I've only installed one PF BB - an allow cup Race Face into my 2014 Carbine 275. Brand new frame, new BB. Installed using the Park BBT-90.3 tool kit used with some threaded rod in lieu of the fancy (and expensive) Park bearing press. Does the same thing, the Park press is just faster (important in a shop setting, less so at home). I then proceeded to beat the ever living snot out of that bike, as I built it with hopes it could replace a DH bike. Four years later, the BB is still silent.

It's been 4 years, but I'm 99.9% sure the instructions for both the frame and BB were to install the cups dry. Something I loath doing, but I also tend to RTFM, so....
 
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Tim

aka sptimmy43
So far, I've only installed one PF BB - an allow cup Race Face into my 2014 Carbine 275. Brand new frame, new BB. Installed using the Park BBT-90.3 tool kit used with some threaded rod in lieu of the fancy (and expensive) Park bearing press. Does the same thing, the Park press is just faster (important in a shop setting, less so at home). I then proceeded to beat the ever living snot out of that bike, as I built it with hopes it could replace a DH bike. Four years later, the BB is still silent.

It's been 4 years, but I'm 99.9% sure the instructions for both the frame and BB were to install the cups dry. Something I loath doing, but I also tend to RTFM, so....

RTFM... this is good advice. My bike's manual does not address the BB installation. I got in touch with the bike manufacturer (YT) and they suggest green loctite. I also got in touch with the BB manufacturer (Hope) and they suggest grease. As mentioned I already installed the BB. I used the Wheels Manufacturing drifts and 1/2"threaded rod because, um, yeah, not spending $200 on the Park Tool press to do the exact same thing.

The interesting thing to me is that there isn't a consensus on the best way to do this. With all the technological "advancements" in bikes happening like every 3 minutes you would think something like how to press a bearing into a frame would be well sorted by now.
 

shrpshtr325

Infinite Source of Sarcasm
Team MTBNJ Halter's
The interesting thing to me is that there isn't a consensus on the best way to do this. With all the technological "advancements" in bikes happening like every 3 minutes you would think something like how to press a bearing into a frame would be well sorted by now.


nah they are too busy coming up with new ways to get you to spend money to sort out something 'simple' like that
 

Johnny Utah

Well-Known Member
1/2” threaded rod with two washers and bolts has put in five or six successful press fit bottom brackets in my garage for a total cost of $3. I use grease in my carbon frames, whether or not it is the “right” way it has always worked.
 
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