I recently purchased a Schwinn Traveler frame which the man I bought it from said had a "smooth-bore" bottom bracket shell, which I assume means that there are no threads in the shell and the cups are instead held together by pressure from the shell. Can anybody tell me if I am completely wrong in assuming this?

Also, I have heard that I do need to get an adapter for the bottom bracket, such as the Truvativ for US to Euro conversion. Is there anything special I need to do to remove the cups that are in there or to install the adapter??

Please help!

pictures???

sounds like a 1 piece crank.

adapter.

If it is an older American oversize bb, then the converter above will work. You can just tap out the old cups with a screwdriver, they will pop right now. The converters work perfect, I used one on an older conversion I did at one point. The only problem I had was that the shell wasnt perfectly round, so I had to hammer the converter in. The tricky part was making sure that I hammered both sides in straight so they could screw together. Just go slow and be careful.

The other option would be to just use another 1 piece crank...not my recommendation...but another option...

There are also USA BB sealed bearings that allow you to use a 3pc crank w/o an adapter. That type of bb will only work with compression style cranks.

They call this system BB1960.

could it be an old phil bottom bracket?

Thanks for all the advice, everyone!!

I actually thought I'd have to go to my LBS and have them remove the cups, but a simple hammer + screwdriver/leverage combo popped them right out. I found out that the BB is indeed a "smooth bore" which has no threads in the shell.

Another question I have is this though:

I took the specs on the BB shell without the cups in, and the I.D. (Inner Diameter) was 52mm, O.D. (Outer Diameter) was 57mm, and the width of the BB shell was about 64-65mm. Will the Truvativ Bottom Bracket Adapter (https://harriscyclery.net/itemdetails.cfm?ID=1335) work on this BB shell?

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I will upload pics later today! I also filed off and chiseled off the cable clips on the frame since I'm attempting to turn this into a fixed/free city beater bike and will only be putting in the front brake.

Another question:

What would be a good (hopefully durable but relatively inexpensive) bottom bracket to put in after installing the BB shell converter?

A basic $25 Shimano UN-53 BB should be fine.

yeah the shimano bb brackets do a good job

It is an Ashtabula bottom bracket... conversion to a cartridge is pretty straightforward and the parts will cost about $75.00.

Has anyone done a modern performance/multispeed version of an Ashtabula BB and 1pce cranks? It seems kind of awesome.

I had yet ANOTHER question to ask:

I've just received my Truvativ American-to-Euro BB Conversion kit and I wanted to make sure I knew the procedure/threading match before performing it on the frame (which won't happen for a while anyways as I'm still in the progress of stripping the paint and giving it a new paint job).

-Am I supposed to install the conversion kit BB shell first, then install my BB? Or thread the BB onto one of the pieces of the kit and then tighten screws to bring the two pieces together (saw some directions online for this, but wasn't sure if it was for the BB adapter that I'm using)?

-Which side of the bike is supposed to have which threaded BB cup? The drive side = reverse (left) thread or normal (right) thread?

Again, thanks to everyone for all your help!

Generally the right side (drive-side) is reverse-threaded.

lol

Right. I just bought one. They are not marked R or L, so I just carefully tried to screw it into either side of the replacement BB cartridge to find out which one was which. Then I marked them with a sharpie. That ink came off shortly into my installation quagmire.

Here is the thread in C&V (don't worry, we've established that my BB shell is a special case):
https://www.bikeforums.net/classic-vintage/603149-american-euro-bb-adapter-problem-3.html#post10042488

lol.

Niagara actually sells a loose ball bottom bracket that fits into a one piece shell but has a square taper axle.

Total price is less than a converter and a new BB so it might be worth a look if you are just looking for a way to get modern cranks on an older American frame and not worried about going cartridge (or to some sort of splined crankset)

Yeah, that may be but I wanted the ability to, for whatever reason, be able to change out the BB and so the converter seemed like a good idea. Thanks for the suggestion though, ottothecow.

And yeah, I figured you'd kind of have to screw one of the shell cups into the BB to see which side is which...thanks for confirming, atoms. And the sharpie idea is also a good one, I'll keep that in mind. Just wanted to be prepared.

does said bottom bracket come with an iso axle so i can run my sugino 75's on my conversion?

Hey everyone,

I know it's been a LONG time since I wrote on this thread, but I've been slowly working on taking the paint off the frame that I'm going to be using and redoing the paint job (it was already wearing off pretty bad, but it's been slow b/c of the winter weather and lack of access to a garage). Anyways, I am getting close to being done and have been thinking more and more about my bottom bracket/crankset combo, and I think I have decided on it. Remember that I said my BB shell is about 64-65mm wide!

Sugino Bottom Bracket 68 x 103mm
Origin8 Track Crankset 165mm 46t

The other crankset I was looking at was this: Sugino Single Speed 165mm 48t Track Crankset - 130mm but I'm pretty fond of the origin8 one that I've chosen.

The main input I'm looking for is...
-Whether they'll all be compatible (BB shell, Truvativ adapter, Sugino BB, and Origin8 Cranks)
-If they're decent quality (for a singlespeed city bike)
-If they're not compatible (i.e. wrong size = sticks out of shell or whatever), what WOULD be the right sizes to get, etc.

I'm really trying to look for confirmation and last-minute things I should know, since I'm very close to purchasing these and wanted to make sure I'm making the right decision.