Aquaman5K

Over the past few weeks, I've noticed a creaking sound coming from the bottom bracket area on my Viscount road bike. It has a Sugino BB with caged ball bearings. Yesterday, I pulled the cranks to check it out, and sure enough, the BB spindle felt gritty and hard to turn. After unscrewing the adjustable cup, I found water inside. Not just a little bit either, there was a puddle of standing water inside the BB shell. I wiped out the water and old grease, and repacked it with lots of fresh grease, but I'm worried that water will get in again, as I ride in the rain often.

I have heard of people drilling a hole in the BB shell to allow water to drain out, and am wondering if anyone has advice for drilling. What size hole works best, and what is the best place to drill it?

Any other ways to keep the BB free of water and rust, aside from overhauling it after every ride?

tjspiel

Any chance you could replace the BB with a cartridge style? You might still want a drain hole but it seems to me that water is still going to be running down the seat tube and getting on the BB.

Putting in a hole large enough to function as a drain is also creating another point of entry.

DOS

I have also heard of people drilling holes. I am afraid to do that, but a simpler solution is to pull the seat out after riding in the rain and hang the bike upside down by the wheels.

carpediemracing 

In the past I drilled a hole in my BB shell to let water drain out. I chose the lowest point of the BB shell, put two small (1/16" 1/32"?) holes in. I haven't done this recently.

You can also do some checking for brazing holes in the chainstays(where the tube has a pinhole to help vent brazing gasses/pressure vent) and hang the bike such that those holes are the low point.

For rust proofing use the sticky brown spray sold by Weigle as well as any automotive store (sold as "self-sealing" and not recommended for painting over). Spray liberally inside the tubes.

cdr

Aquaman5K

A cartridge BB sounds like a good idea, so I think I'll swap the old one out for a un-54 this weekend. Do you think using a generous amount of good grease on the BB shell threads will be enough protection if a little water manages to get around the new cartridge BB?

2_i 

One could drill a hole and then put a bolt into it. Water, particularly over time, should be able to sift through the threads, but the hole would not really add an entry point. Also, there is this Dry Valve by Action Tec.

SJX426 

The hole needs to be large enough that the water doesn't come out due to water tension.

HillRider

Most bottom bracket shells have at least one 5mm threaded hole to allow a bottom bracket cable guide to be bolted on so it's obviously not a problem if you add a second one that size.

As to a cratridge bb, grease the shell and threads just to prevent superficial rust. Water won't get to the bearings.

BTW, there were plastic cylindrical sleeves commonly used with cup-and cone bottom brackets. They were sandwiched between the cups and covered the bearings and spindle to provided a measure of protection from dirt and water.

BCRider

Nope, the screw in the threading will block the water from flowing. Surface tension and all.

I think you intended this to be "the hole needs to be large enough that the water doesn't get stuck due to surface tension" If not then it should have.

If an opening is too small it can hold in quite a bit of water before gravity overcomes surface tension. For this reason I'm not sure that the Dry Valve is a great idea either.

There's another good reason to just drill the customary 5mm'ish hole. Not only does it allow a free flow of water from inside but it also forms a large enough opening to encourage a flow of air and help dry away any residual moisture trapped inside.

Yes a hole of this sort will allow the odd splash to get in. But we've already seen that the collection of water from other entry points is pooling far more water in the BB shell than a drain hole would ever let in.

So by all means drill a 5mm or 3/16 hole in the shell at the lowest possible point. If you lean the bike to one side more frequently than the other drill the hole closer to that side. Ideally right where the inside edge of the cup is sitting. Be sure to chamfer away any burrs inside so there's no little dams left to hold in any more water than you can get away with.

Finally apply a smear of boat trailer wheel bearing grease to the entire inside of the shell. It's more water resistant than any others I can think of so it SHOULD help avoid any further rust formation. Use more of the same stuff for the BB threads for the same reason.

Something that would be interesting is if frame intended for serious amounts of riding in rain were to have a drain nipple on the shell to which a short 2 inch section of plastic tubing could be attached. The nipple and extension would easily allow water from inside to drain and also encourage airflow through the tubes for drying but at the same time the tubing would shield water from getting in from anything other than the worst possible sort of dunking.

Mike T.

Use my "Jiggle Valve" - get an old spoke and straighten the j-bend the best you can. Chop 1/2" off the head end. Get a drillbit that's slightly smaller than the head. Drill the hole in the lowest part of the BB shell. Drop the spoke though it (from the INSIDE of course!). Re-install the BB unit. Now any water drains out and the jiggling spoke will keep your hole unplugged

BCRider

Slick idea Mike!

froze

What a bunch of mumble jumble. You simply need to drill a 1/4th inch hole with the bb removed as not to accidentally drill into it. Then paint the fresh cut hole so the metal doesn't rust there, start with a primer then paint to match the frame...if you want even though no one would probably ever look there for the paint to match.

As far as water getting down there, you need to stop the source of it...don't ride in the rain...just kidding. You should grease the seat tube and seat post with a thin layer of grease on both. I know that my rear and front flasher came with a rubber strip so I just push it against the seat tube and the head tube (I have threaded system) and they seem to keep water out. All I know is that my steel Trek is over 30 years old and never has been treated with rust prevention gunk like the Mercian has, and there is no rust inside at all.

2_i 

Oh yeah?! Try to maintain water in a container that has a drilled hole which is bolted, in addition in a container that is shaken. In any case, the screw works for me.

BCRider

A machine screw head tightened into a flat surface provides a pretty good seal against anything that isn't pressurized. Oil would seep out over time but it has a lot less surface tension than water.

The threads would need to be pretty loose fitting and in addtion the screw not tightened to let it out. And surface tension in the threads would still retain the last 1/16 to 1/8 inch or so in any event. But I'll grant you that if it was loose enough to rattle then it would let water out and perhaps even act as a pump of sorts to encourage the last bit to dribble out as well as the screw rattles in the threads. Sort of like Mike's spoke trick. But if it was that loose it would need something to retain it in the hole instead of rattling out onto the ground. Still, that may be something to try at some point.

2_i 

The shell is not very thick. The threads never really have a chance there to close off fully the opening on their own, without a washer. Some water, of course, will remain, but that this granted under any circumstances. One just needs to come to a situation where the remaining water has a chance to evaporate over openings that it might have come in.

With the Mike's trick, I am afraid of the opening working too much both ways. Of course, this spoke would need to be bent outside or flattened as well and one could do it with a loose bolt as well, say with a locknut.

froze

Why would you all go through the trouble of using screws or valves or whatever? Just drill a hole and leave it open. For gods sakes men, there are plenty of bb shells out there that used several long slots for water drainage with no thought whatsoever about screws and valves or whatever you all can dream up of.

https://cdn.mos.bikeradar.com/images/...-90-480-70.jpg

Just keep it simple and drill a hole and forget about it.

bionnaki

be sure to tap a small initial hole before drilling...or the drill might walk and mess up the surface.

BCRider

That would be as in "centerpunch a mark to start the drill"? Yep, a darn good idea.

Froze, that's a little extreme isn't it? From the nice job highlighting the edge with red paint I'm suspecting a fancy track frame or at least some sort of clean living racer frame.

froze

Actually almost all Italian and French bikes were made this way, that's just a regular road bike with Nervex bb shell. I had bikes in the past with slotted lugs.

See more:

https://www.raydobbins.com/ebay/bike-...i/photo_42.JPG
https://www.lfgss.com/thread30406.html
https://media.photobucket.com/image/s...er/5a93_12.jpg
https://www.dominguezcycles.com/image...4/lres/031.jpg
https://www.ceeway.com/NEWPARTSPAGES/...S/new_pa33.jpg (looks the way mine does after the drilling)

There are other designs I can't find pics of but you get the point.

operator

Hahaha

/tear

2_i 

Under my conditions, I'd be swapping sealed BB bearings once a year with this kind of slots

BCRider

Thanks Froze. Those picture links go to show that even after 18'ish years of serious biking intrest that there's still much to be learned.

BCRider

Not really, even with those vacuous openings the seals themselves would only see the same end exposure that they would with a non ventilated BB shell.

2_i 

I have other sealed bearings this low and have now statistical evidence of them being gone after a year in my conditions. This has been stopped by going to ceramic. All the BBs I have, so far, used had cups that provided additional and likely more thorough external sealing than BBs themselves. The cups do not need to meet any, excessively demanding, standard of thickness. However, I do remember cups that gave no sealing, which I avoided. My experience is from cartridge BBs, but when I look at sample cup and cone BBs on-line, they seem to have at least potential for better sealing than cartridge bearings alone.

In any case, there must be a good reason why slotted shells have departed into the past, together with U-brakes and such.

froze

The reason slotted shells have departed into the past is because AL and CF frames don't need them; there are still custom built French and Italian steel done this way. You need a drain hole for water to escape and even condensation over time can be damaging and thus needs to be drained. If the slots and holes were not important then why remove the seatpost and hang the bike upside down to drain? sounds kind of silly now doesn't it? When a simple hole could drain the water automatically without a thought or effort on your part. I've had the same bottom bracket for 30 years and over 150,000 miles with the hole in the shell...of course routine maintenance of the bb is very critical for long life.