I recently purchased a second-hand 'new' Panasonic frame to replace my current one. It's a steel Panasonic 'livespot' frame. To my surprise, it didn't have any threads in the BB shell. I went to 3 local bike shops and they all told me they couldn't cut any threads so I'm not sure what my options are.

I'm a complete novice when it comes to bicycles so I might be missing something, but I'm honestly completely lost. Any advice would be greatly appreciated.

Unfortunately I can't post any images/URLs due to my account being new. I've uploaded some pictures to Imgur, you can see them by adding /a/vfME4T5 after the imgur domain.

Thanks!

Welcome to C&V. It's a friendly, knowledgeable crowd.

There are bottom brackets that stay put without threads. I don't know about them in any detail, but somebody else here will. With any luck, there is a reasonably available solution for you.

Thanks for the warm welcome!
I've been reading through a couple of the posts and I'm amazed that I didn't know of this community sooner. The sheer amount of people, knowledge and passion is incredible. I'm looking forward to spending more time here.

Link assist: https://imgur.com/a/vfME4T5

I've never seen anything like that. Your best option is to call Panasonic and ask for any information regarding the bottom bracket; might be proprietary. Alternatively, if you're a risky knucklehead like me, you can try to remove what looks like a shell/shim in the bottom bracket using a hammer and punch. Just don't go at it all ham-fisted, that thing looks like it's made of aluminum.

Can you measure the inner diameter of the bottom bracket as it is now?

philpeugeot is right, it looks like it has some sort of lining or shell that might be able to be pushed out. Telling us the diameter will give us a clue as to whether that's a good or bad thing to do. For reference, the inner diameter of a BSA bottom bracket is 33.6mm or so.

Thanks for the replies!

I couldn't find any contact information on their JP website, so I just went to their closest POS dealer. Unfortunately the guy there couldn't help me but he said he would ask the owner of their shop when he comes in. I should be receiving a reply later today. Worst case scenario, I'll try to find a way to contact Panasonic through them.

The shell/shim is very intriguing, I didn't notice it so thanks for pointing it out. I'll post the dimensions like scarlson suggested when I get home today in a few hours.

That micro-splined inner surface looks like the steel bb shell itself is designed for a press-fit bearing, much the way that some Schwinns had a similar pattern of ribs on the OD of the steerer for the press-fit crown race.
The raised surface reduces the need for close tolerances, allowing for no machining needing to be performed, and so reducing cost.

Not sure though what kind of bottom bracket assembly goes in there, but the ID could be compared to common bearing sizes like 35 or 36mm.

My measurements of the inner diameter varied from 33.5mm to 33.8mm. I measured the width while I was at it which was 70mm. I'm not sure if the outer diameter matters at all, but it was roughly 42.8mm.

I hadn't considered the possibility of it being press-fit before. Are there any press-fits with these dimensions? To add to that, is there a possibility I could use thread-together bottom brackets?

I tried looking all over the frame to see if there's a manufacturing year or anything that might give a hint to the era, but unfortunately I couldn't find anything.

I still haven't gotten a response from the shop but it should come sooner or later.

Thank you all for your responses so far, it's been a great help!

Pic Assist - https://www.bikeforums.net/g/album/22971826

I'm in to find out about this one.

I'd like to see the whole frame.

There are some cartridge bottom brackets I have come across for utility bikes that have plastic cups that might be the form factor.

the inside diameter is probably too small for an eccentric lock cartridge bottom bracket.

this is an uncommon one for sure.

There are a few threadless cartridge BBs out there, e.g., https://www.modernbike.com/product-2...4aAjqNEALw_wcB. Not sure if the OD would work, however.

cb400bill The best I can do at the moment is this. It's dark here now so it'll be until tomorrow until I can take a picture of the whole frame.

I've also uploaded a picture to that with some BB related stuff that the seller gave me with the frame, but it's quite incomplete and I don't know if it helps much.

Pictures: add /a/whGMM99 to imgur domain

Luckily I'll be able to post pictures soon at this pace haha.

nlerner Thank you for linking that, that seems like the most promising solution at the moment. I'll have to look around a bit because the cheapest one I can find in Japan is a whopping 160 USD. I'm sure there is a similar cheaper bottom bracket I can find here.

Here is some info on the Velo Orange threadless BB. They don’t have them in stock now but you may be able to find one elsewhere on the interwebs.

https://velo-orange.blogspot.com/200...-brackets.html

33.5-33.8mm ID is very close to the ID of a standard BSA bottom bracket thread. This, combined with the slight chamfer on each side of your bottom bracket shell, makes it seem like the ideal candidate for a bottom bracket like this:
https://www.ebay.com/itm/373738703299


They are sold under the brand names "Sunlite" and "YST" here in the USA. I bet you could find one in Japan!

I used one for a couple years on my commuting bike. It had to be quite tightly screwed together, or would come loose, but a little threadlocking compound helped with this.

Edit: I see [MENTION=45088]nlerner[/MENTION] already mentioned this option.
I do think the Velo Orange is probably higher quality.

appears to have been some sort press fit cup, maybe for maybe for something like the shimano front freewheel ????

Did the OP try a magnet on the BB shell and/or on those "splined rings" assuming they might be separate components to the shell?
If aluminum then maybe not a good candidate for reaming and threading but, given the wall thickness if it's steel then the fact of it being at most 33/8mm and 70m wide seems like perfect for Italian threading. But you'd need to find a shop who can do that.
Cheaper solution might be one of the no-threads-needed BB units like aforementioned VO, YST or Sunlite.
AND you'd want a shop to machine the chamfers on the outbound BB shell edges, and YES do use LocTite Blue if you go with any of these 3 brands.

You might want to also check out Mavic's threadless BB from the mid 80's......
Here's some info on it from Le Cycleur's site....
https://lecycleur.com/parts/mavic-bottom-bracket/

Sunrace makes a Thompson Press-fit bottom bracket, cottered and cotterless
appears to have plastic cups- $20 range

If you look closely, there are chamfers on the inner edges of the sleeve already. That and not matching up with any of the Thompson diameters makes me think it's meant for the "Mavic" style BB (similar to the YST/Sunlite).

However, if the sleeve is removed, it may match up with the bigger 38mm Thompson.

Maybe this place is worth contacting, as they're likely knowledgeable? https://alexscycle.com/products/pana...rame-460-630mm

(Scroll down to the bottom of the page for contact info, including phone number.)

I don't see any sleeve there at all, even the weld or casting ridge appears clear across the inside of the bb shell.

Beware of ordering from Bikewagon. I have twice had to return items which were (I believe deliberately) marketed using photos of higher-quality merchandise than was actually shipped. The Sunlite bb will likely be far, far cruder than the YST unit shown!
It's just how they do business online I'm afraid.

This bb shell is a good candidate for either Italian threading (it's already at 70mm) or for one of the threaded-together and chamfered models of "threadless" bb's.
Note that a threaded-together bottom bracket intended for 68mm will end up offset 1mm to the right in a 70mm shell. So you'll want to order a 2mm-shorter bottom bracket spindle length than what the crank is spec'd for.

35mm OD cartridge bearings may press right in, but getting the right spindle to complete the assembly will either be expensive, or hard to find cheaply.

The consensus seems to be trending towards a press-fit, which may well be right (and I can't actually think of any alternatives) but a good press fit connection shouldn't have splines like that. That only reduces the contact area and is a recipe for slipping and creaking. Also, the variation in the diameter argues against a press fit, which should have tighter tolerances, though it isn't clear whether that's a measurement precision issue or damage from the slings and arrows of outrageous fortune. Finally, that's a metal insert, in what appears to be a metal BB shell, where threads can be cut. Press-fits are for composite frame mfrs that are too lazy/cheap to use a metal insert. It's hard to imagine Panasonic to be guilty of such schlamperei so I wonder if we're missing something here.