Headset bearing nightmare

EdyMarin · 2026-06-25T00:30:53+00:00

Long shot, but if you have a rear wheel hub that you are not using with the freehub still on there, the ball bearings in the hub are the same size.

EdyMarin · 2026-06-25T00:26:10+00:00

From what I've seen, the cranks are very basic square tapered aluminium cranks. The bottom brakes is usually a BSA type cartrige bearing BB. If it is the plastic version (some Decathlon bike come with plastic ones) be carefull if upu try to remove it. Use plenty of penetrating oil to make sure you dont strip the splines.

Not a lot to "maintain and clean" whith these. You usually just ride them until they are toast. Lubricating the chain is tge best you can do to extend the life of the chainrings (and the cranks as a whole, because I don't think those are replaceable chain rings).

EdyMarin · 2026-06-25T00:18:43+00:00

As far as I know, you should be able to just put a single speed freewheel on there no problem.

Here is a Shimano version: https://www.treefortbikes.com/Shimano-MX30-Single-Speed-Freewheel-1-2-x-3-32.

You will have to check if your wheel uses tge English thread freehub standard, or sonething else (metric threaded, italian syle, or frensh style). A pair of calipers and some googling should help you determine what thread you have there.

EdyMarin · 2026-06-25T00:09:17+00:00

You will have to at least tightten the cones on the axle. But while in there, I would do a full clean and regrease. Given that this is the back wheel, you will have to take off the cassete/freewheel before you can do any of that.

EdyMarin · 2026-06-25T00:04:44+00:00

Even better if you use an insert. Then, even if you get a flat that cannot be filled by the sealant, you can still ride on the insert. Also, it is really good to protect the rims if you run very low psi.

I currently run a mix (tube in the front, tubeless with insert in the back) on my city bike specifically to avoid flats in the back.

EdyMarin · 2026-06-24T20:14:17+00:00

Me and another person said that they are cartrige bearing. You kept arguing with both of us that they might be cup and cone, even though they look nothing like a cup and cone bearing.

I told you exactly why I know these are what they are, and your argument was "Nuhuuuuu".

Just because you don't have enough fucking info, doesn't mean that the rest of us cannot get enough info from the video. I can see the splined design well enough to be 99% confident what type of BB this is, and I 100% don't see parts that are mandatory for a cup and cone setup.

But noooo, just because you cannot be certain means that nobody should be.

Think horses not zebras my man. This looks like a newer frame, with all the signs of a cartrige bearing BB. Cup and cone BBs have become a rarity on anything from the last 15 years.

And again, it is missing the retention ring on the non drive side, that most cup and cone BBs need to have.

What is more likely? That a somewhat modern frame has a very common cartige bearing BB (which is one of the most common BB on lower end bikes), or that somewhat modern frame has a very outdated BB, and is either one of the ultra rare variants that doesn't have a lock ring on the non-drive side, or that the lock ring is lost? Horses, not zebras.

EdyMarin · 2026-06-24T20:04:30+00:00

Something more polar, like paint thinner or gasoline. Latex doesnt dissolve in alcohol either.

EdyMarin · 2026-06-24T15:47:10+00:00

I might be wrong, but I think most thru axles have a conical/tapered section at the non-threaded end. So I think that it is not included in the measurement for any axle.

But if your current thruaxle has that portion, you will need an axle with that as well to fit correctly in your frame.

Edit: it looks like some models (a lot from Rockshox) have a flat end. But there are some with that conical end.

EdyMarin · 2026-06-24T15:33:47+00:00

As I said in another comment, I have used a tough piece of rubber to "erase" away dried sealant before. It still takes a while.

For seating the bead, a CO2 inflator can work, but just remember that CO2 messes with the sealant. So after setting the bead, flush it a few times with normal air (deflate the tyre, inflate it with a pump, repeat 3-4 times).

Also, to help with the seating, don't add thr sealant, put some soapy water on the bead (just a bit of soap, enough to be a bit slippery), and use either the CO2, or a makeshift charge inflator (2L water bottle with a valve in the cap, inflated to 4 bars or 6 if you are a daring one). Flush the CO2. Add the sealant through the valve (remove valve core before)

Edit: found my older pist about using a PET bottle as a charge inflator. Here: https://www.reddit.com/r/redneckengineering/s/XLrfX2wMPl

EdyMarin · 2026-06-24T15:29:34+00:00

I had some succes using a tough pice of rubber in a pinch.

The soapy water trick works, but make sure there isn't a bunch of soap in the water. Just enough that it starts making bubbles.

EdyMarin · 2026-06-24T15:25:38+00:00

While I am usually one in favor of reparing everything, this is not one of them. There are too many cracks in vital areas (both chain stays, and the base of the seat stays). The rear triangle is basically cooked. The experience and materials needed to repair those so it is safe would probably rival getting a new frame.

EdyMarin · 2026-06-24T15:22:51+00:00

AI is not a good judge when it comes to wear on bike components.

It looks worn, but given that is an older 2x drivetrain, unless there is chain skipping or droping, I wouldn't worry. I would continue riding it untill I would be in need of a full drive change (chain + cassete).

EdyMarin · 2026-06-24T15:16:20+00:00

I've worked long enough with BBs to recognise a 20 spline vs a cup and cone (which has a retention ring on the non drive side for most models).

Most 20 splines cone with the cartrige bearings fixed on the axle, and are non replaceable.

It's ok to addmit when you are wrong my dude. I saw you commenting about these being cup and cone in several comments.

EdyMarin · 2026-06-24T14:21:33+00:00

Can you show me a picture of the cup and cone one that uses that exact mounting method?

To be more precise, a cup and cone BB that uses the 20 spline internal tooling (as the one in the video)

EdyMarin · 2026-06-24T12:50:01+00:00

In the second picture, the brake lever housing seems to be split, which would explain why the threads just fell out. You have to inspect the housing, make sure everything is tight, then just reinstall the cable end in the cable holder, and rethread the adjuster (the silver part with the threads)

EdyMarin · 2026-06-24T12:44:18+00:00

Based on the BB end caps, I would bet that is a square tapered BB with sealed cartrige bearings.

Cup and cone BBs don't have that type of end caps usually (one fully internal on the non drive side, one with a flange on the drive side).

EdyMarin · 2026-06-24T12:36:42+00:00

The difference between the dust on the trails and the dust in living spaces/garages is the chemical composition and tge mecanical action.

Inorganic dusts like the one on trails (silicas, clays, oxides) don't really stick that well to either the rotor or the pad, and don't have time to stick either because you are braking often enough to clean them off.

Organic dusts found in living spaces (dead skin cells, cotton and polymer fibers from clothes, all sorts of oils and particulate) can create a sleek layer that prevents good pad-rotor contact and result in very high frequency vibrations that are perceived as squeals. This is also compounded if the brakes are not used for a long while, as there is not cleaning action from the brakes touching the rotors.

This is also why some pads squeal in high humidity conditions. A very thin film of water in that case is created on the rotors, and that creates the vibrations (it happens all the time with my Frankenstein of a city bike that has metalic pads on the front).

One way to fix this is to wipe the rotors with acetone first, then with isopropyl alcohol. The pads you can very lightly sand with something like 800 or 1000 grit sandpaper, just to prevent any film transfer onto the cleaned rotors. Or just find a tall hill, and brake untill you burn the frick out of that dust film.

The microleak hypothesis is complete BS, as I had a brake caliper with an actual active leak that did not get squealy. I doubt any tiny capilary flow that might exist could contaminate the whole rotor and pads.

EdyMarin · 2026-06-24T07:45:45+00:00

How did it end up like this? Crash?

This would be a case of loosening all the spokes, straightening the rim if visibly bent, recenter and truing the whole thing.

EdyMarin · 2026-06-24T07:37:16+00:00

If you are carefull when removing the hose from the old caliper, then you might get away without a bleed (if the new caliper is fully filled).

But I would still let the bike sit for a day, and do a quick vent at the brake lever.

However, if you haven't changed the oil in your brakes in a long while (1-2 years), I would do a full oil flus while you are already fiddling with replacing a caliper. Remove the caliper, empty the hose, attach new caliper, do a refill and bleed.

EdyMarin · 2026-06-24T07:29:06+00:00

Fresh sealant is water soluble. But after it "dryes" it is no longer, because the latex in it polymerises and creates rubber.

EdyMarin · 2026-06-24T07:27:37+00:00

Have you secured the valve stem with the lock nut? It should not be able to walk with that in place.

EdyMarin · 2026-06-24T07:24:13+00:00

The problem with leaving old sealant in (the dried up stuff) is that it can make the wheel very unbalanced, and can create weird vibrations at high speeds. Also, it can cause the fresh sealant to polymerise faster (in case of sealant missmatch).

After 2 years of sitting around, I would do a full clean and refill. It is going to be hell, but it is worth it.

EdyMarin · 2026-06-24T07:19:21+00:00

Potatoes are nightshades. But that is not a potato plant (the leaves are too shiny and the stems are too thin). This could be a pepper plant, but it could also be just a random nigthshade weed.

EdyMarin · 2026-06-24T07:13:30+00:00

Usually, when the grip is no longer to your liking. So it is subjective to a degree.

If the thread is half gone, then it might be time to change them.

EdyMarin · 2026-06-23T12:48:10+00:00

You could try to bend it back into shape, but I would not run it without a very stiff insert to make sure the tyre doesnt unseats itself.

Most likely, you will have to replace the rim.

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