VintageSteelEU

I remember reading something about swapping BB spindles on Sheldon Brown's website in the past, but can't seem to find it now. So I thought there might be some forum members with knowledge regarding the subject.

I'm slowly gathering pieces and funds for this Winter's project, which is Motobecane C5. It came with a Stronglight Competition BB with Swiss threading, but I've basically used (almost) all the components I got with it for a Grand Sprint build. What I'm planning to do with C5 is to go for lightweight & Japanese components (I've got Suntour Superbe 1st gen derailleurs and shifters, SR Royal-5 Extra Super Light crankset, haven't decided on stem, handlebar, hubs and brakes yet). The problem, as usual, is the Swiss BB threading. On my other Moto I use IRD BB with Swiss threaded cups, but it seems they are not that easily available any more. I happen to have a set of traditional cups with Swiss threading (and a 126mm spindle, which is 1. too long 2. probably ISO taper) so I was wondering if I could use the Swiss threaded cups and get a JIS tapered spindle in the correct length (112mm) or some English threaded, JIS-tapered BB as a donor. Bearing ball size is the same, the width of the BB shell is the same (68mm). Is this a viable solution?

Mr. 66

I don't know why you can't. If the spindle/bearing specs match the thick or thin-ness of the cup I don't see how a swap would not work.

Hondo6

https://sheldonbrown.com/bbtaper.html

3alarmer 

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...back about ten years ago, when I still had access to a huge box of old loose ball spindles at the bike co-op, I did a lot of spindle swapping. My experience leads me to believe that people often make too much of the JIS/ISO incompatibility.

It's not really all that simple as yes or no, and you need to do some dry fitting and mockups, to figure out whether you can make a crank work with your frame and chosen spindle. And there are some really surprising things you discover along the way, like the years when Campagnolo cranks were actually closer to JIS than ISO. If you read that Sheldon Browne material linked above, you'll soon figure out that a nominally JIS taper will push your crank arms out farther, by a mm or two.

What my own experience led me to, is the realization that I no longer can find the endless supply of old loose ball spindles that used to be available, that makes this practical as a solution.

With something like you are describing, I would probably just ream out the BB shell, and rethread it Italian. Then buy some sort of sealed unit square taper in the appropriate length, and call it good. But I have the tooling to do this, and it might not be the best solution for you, unless you have access to someone or some place with the stuff you need to do this modification. And you might have access to a large collection of loose ball spindles. So mostly just realize it will probably take you several tries (maybe more), to find something that works well.

So if you're buying them used, or online somewhere, the costs can add up after multiple tries.

eeuuugh

I don't know about IRD's distribution in Europe, but the Swiss conversion cups are available in the US in Soma Fabrications' shop here.

3alarmer 

.
...yes. If I could get them, I would use those as the simplest and most straightforward solution.
The Phil Wood Swiss retaining rings still show up as available, online. Link

Nothing Phil Wood sells is cheap, but it's all high quality and very durable. Lifetime guarantee, and that sort of thing.

79pmooney

Does Phil Wood do Swiss? Does Shimano on their cheaper BBS? If yes to both, the easy way to get exactly what you want is to buy the Shimano, mount it, put on the cranks, measure where they sit and where you want them. do the math to come up with the spindle length you want and its asymmetry (if you want that; I always go to get Q-factors down to where my knees are happy.. Call Phil Wood, place the order and rake out that second loan. In a week or so you will have a unit that looks high tech medical in quality and appearance that you can pass on to your grand kid. (The one who causes your son so much grief. Tell him he has to find a Swiss threaded frame to put it on. That should keep him out of trouble for a few years.)

Shimano and Phil are both very close to JIS spec. Phil BBs should put the chainring within a mm or 2 of where Shimano does. And Phil gives you adjustment ability to boot.

VintageSteelEU

OK, taper is not really the problem. As you have noted, in some cases ISO might work. If I need a 112mm JIS, I could probably use slightly longer ISO spindle. But not 126mm long. So if I'm getting a shorter spindle anyway, I might as well go for the correct taper.
Another thing here is that SR Royal-5 ESL is not an easily obtainable crankset, especially in usable / good condition. So I'm not too keen on even a slightest chance of messing it up
As for Italian threading, that's a design flaw Their BB's also use typically a 70mm wide BB shell, the one on the bicycle is standard 68. It's also threaded the same way as British standard, just a different thread (1.378 x 25.4tpi instead of 1.375 x 24tpi). So if there was any re-threading going to happen (which I don't think there's a point in doing), it would have to be brazing over the existing thread and going British.

The problem is that the cones / bearing stop on the spindle is in different position. So I'm wondering, since the bearings are all the same size (it would seem), would it be safe to use JIS spindle with the Swiss cups considering the slightly different position of the cones?
I'll show what I mean. ISO spindle upper part of the photo, JIS at the bottom.


ISO (Swiss threaded BB) versus JIS spindle
And another comparison is Italian ISO vs Swiss ISO (different BB shell width)


Italian (Ofmega) ISO vs Swiss ISO

VintageSteelEU

Nobody does Swiss threaded BBs as such any more (IRD and Phil Wood make cups). They were not exactly popular back in the day, the only major volume manufacturer using the standard, I believe, was Motobecane from early 70's until early 80's (and apparently some Swiss manufacturers, I don't know any Swiss bicycle brands, though I did stumble upon something made in Switzerland). Perhaps some other French manufacturers did follow the example to some degree.
Two easy options are IRD conversion cups (with IRD BB and probably some Shimano ones) and Phil Wood (which are: a. expensive b. require special tools c. not popular in Europe because of reasons a and b). Or threadless BBs (which usually require some modifications of the BB shell as well)

Oh, I found what I couldn't find on Sheldon Brown's website:
"French bottom bracket cups usually have thinner walls than Japanese ones, so the bearing ridges on the spindles are farther apart. If you use a standard Japanese spindle, the adjustable cup won't be able to screw in far enough to snug up the bearings, or if it does, it will sink into the bottom bracket shell so that you won't be able to install the lockring.

The good news is that a Japanese spindle made for an Italian size (70 mm) bottom bracket will usually fit! In the J.I.S. marking system, these are the spindles that are marked with a "5" code. Spindles for 68 mm bbs have codes beginning with 3. This trick often makes it possible to upgrade an older bike from cottered to cotterless cranks, at a reasonable cost, or replace a worn French cotterless spindle that is no longer available -- but see warning below about French crank extractors."

Now the question is whether French and Swiss cups are the same, thickness-wise...

Well, another thing is that SR Royal-5 is apparently ISO, according to Velobase. So something to double check.

3alarmer 

...you can buy the cheaper rings at that link given to you at soma fabrications, I know you can get an IRD cartridge that will fit them on ebay. I do not know if IRD is still making and selling them in a variety of spindle lengths. When I try, the SOMA website loads the rings into my cart, so I presume they are still in stock. But I think this sort of cartridge with both cups removable, so you can choose, is gradually disappearing. Except for Phil, which is admittedly quite pricey. I have used Phil BB's on occasion, but it is a pretty special occasion.

...I know it might seem this way, if you have never done it. I have done it, on an older Ron Cooper road frame that I happen to like, but which had significant BB threading rust due to prior misuse. The difference in BB shell widths would be an issue if you were using loose ball BB parts. With a decent quality sealed unit BB, which has all the bearing races internal to it, it's pretty much a non issue.

You install it, using a drive side spacer, and the adjustable side retaining thingy might stick out a thread or two more. I would just say trust me on this, but it's the internet. Maybe if there's anyone else who has done it, they could help reassure you.

Here are pictures of the thing being done. It really does work, but if you can buy and use the IRD stuff, that's what I would do, since your bike is not damaged in the shell threading.


before

during

after

I ride this bike here all the time, with it's Italian threaded bottom bracket. The sealed unit Italian BB's are much less inclined to back out on the drive side under use, but that's why God has given us Loctite.


... that has never been much of a problem , IME. But I was not doing much spindle swapping with French stuff, which was already disappearing in our used parts stream at the co-op ten years ago. And while some Swiss threaded stuff made it to market here, almost every Motobecane I've encountered on this side of the Atlantic was threaded French (or after a certain date, standard). As stated previously, it doesn't hurt to do some dry fitted mockups, and see how they turn out. In fact, I don't think I've ever done a spindle swap that didn't take at least two or three different tries. There is a lot of information on what does and does not work in the 4th edition of Sutherland's manual. I have a copy, and it still takes me several tries.

The only issue is what it's costing you for each experimental failure. In my case, it was costing very little, because I had that huge box of cannibalized spindles. Now I don't.

3alarmer 

...those are the spindles that we used to use to convert an older Raleigh Super Course from cottered to cotterless, because of the Raleigh shell width on the proprietary threaded ones (they came both ways...standard and Raleigh). They quickly became impossible to find in my local used parts stream. I guess they might still show up on the used online marketplace.

awac

Sheldon is correct. Swiss cups will work with Italian spindles. The internal bearing shoulders are wider apart and the cups are thinner. Using a standard 68mm the cups will not tighten against the bearings.

VintageSteelEU

I'll have to do some searching. I have one spindle from an Italian BB, but it's Ofmega and they had different standards at times. And at times they didn't. Kind of like every manufacturer, it seems. It's close, but about 0.5mm too wide apart on each side (aldo, too long in total). The other Italian bottom brackets I have are cartridge ones, so no use here. For now I asked some eBay sellers for measurements, we'll see if anyone replies.

Charles Wahl

I'm not sure why you think these aren't "easily available".

https://www.interlocracing.com/shop/...cket#attr=1107
If you need help, I could buy them on your behalf and ship from USA -- provided you can wait for a couple weeks.

3alarmer 

Quote:

Shipping

https://www.interlocracing.com/ird-ordering

JohnDThompson 

Yes. And French. And Raleigh 1-3/8" x 26tpi. And Chater Lea. And T47.
https://phil-wood-co.myshopify.com/c...ottom-brackets

No. But Phil mounting rings fit some other cartridges, e.g. SunTour, EDCO.

dddd

On my Swiss-threaded 1979 Peugeot PX10E or PXN10 I used an older Shimano 115mm cartridge bottom bracket having aluminum cups.
I greased the threads heavily and "worked" the cups in using a large 1/2" breaker bar, back-and-forth until the cups settled in against the bb shell on the right and against the cartridge on the left. The frame's threads seems to have cut new threads into the alloy cups on the bb, and I've been riding this one for over ten years now.

VintageSteelEU

Yes, shipping from the US is frequently a bit on the pricey side. Thank you for your offer. For now I'm checking all suppliers who might stock them in the UK and Europe (though shipping from Europe is not much cheaper than shipping from the US these days, Brexit benefit or something). Overal, over the past few months I do have problems obtaining things in the UK, be it Swiss threaded bottom brackets of IRD variety (that's not a frequent purchase though), but silly things like spokes, spoke nipples, nipple washers, rim tape, inner tubes, tyres, rims... to mention just a few things

Just ordered a loose SR Royal BB spindle in 112mm. Wasn't expensive, so though might as well give it a go. I think what I have to do today is to dig out that crankset, all bottom brackets I have knocking about and check the taper. Velobase says ISO, which I totally forgot about (because Sakae Ringyo being Japanese, I expected JIS). But best to double check, I think. If it's ISO, IRD BB wont be a good solution because their bottom brackets are JIS. The same goes for Shimano. So the new headache will be to sort out what bottom brackets IRD conversion cups can be used with and who makes them with ISO taper ;D

I think overall I would stick with the headache of choosing the correct spindle to work with the cups I have and the crankset I have. Also because I'd like to use parts that would not be out of place in the late 70's. The required length (112mm) might make it a bit of a challenge, but I'm sure Campagnolo (well, that's another can of worms), Miche, Stronglight or some Japanese manufacturers must have made bottom bracket in this or similar spindle lenght and correct spacing of the ridges. Or perhaps it's time to start a vintage parts factory and make loose bearings bottom brackets a thing again?

Classtime 

Just to share my experience:
I must have been lucky with my 1977 Swiss Motobecane G.R. I swapped either a Stronglight or Sugino spindle to use with a Shimano crankset that worked fine. The shoulders matched. Maybe that spindle came from a Somec that I put to the curb many years ago because I couldn’t remove the stem. (I’m smarter now.)

VintageSteelEU

That could be an option with IRD conversion cups as they are aluminium and I do have British threaded ones from the time when I got my set of Swiss ones. Or just use whatever comes with a BB. It would seem that whereas JIS reigns supreme in square taper cartridge bottom brackets, there are still some companies making them in "Campagnolo" square taper (such as Miche and Tifosi). So something to keep in mind.
My commuting Motobecane frame came with the bottom bracket below. Nadax Favorit. They are sometimes listed on eBay as Swiss, because the company was Switzerland based, but I have only seen Italian and British threaded ones. Mine is British threaded and it was sitting in a Swiss threaded bottom bracket shell. Because it's aluminium, I think it worked kind of in a way you describe, most likely by accident. BB shell thread just cut into aluminium on the drive side. On non-drive side thread doesn't matter because the lockring threads onto the bottom bracket body. That same frame now uses IRD Swiss threaded bottom bracket and also another Swiss threaded cup I have goes in without an issue. However, when I tried it on another, Swiss threaded frame (the one I'm going to work on), it will go a few threads in and then not so much. Because the "lockrings" are also aluminium, it might be actually quite difficult to forcefully "re-thread" it the way you described (but it explains why they are so worn out). I might not have enough purchase with the standard lockring spanner and it doesn't have any spline, like Shimano standard bottom brackets. Might be challenging.
It's actually the best bottom bracket I've seen to date, it's way smoother than Suntour Superbe with very fine grade loose bearing balls. The spindle length is 114mm, so a bit too long (but I might be able to live with chainline being 2mm out of spec) and looking at it right now it seems the taper might be ISO (12.6mm at the end). The crankest taper... well, that's still a guess. I seems to be 12mm at the very thin end and 13mm at the wide end. It goes noticably further down on the known JIS spindle than it goes on the Nadax one (without actually using any bolts, so it's eye-balling it, not scientific measurement).



I mean, in the end, the difference between ISO and JIS is not that great, as mentioned by people above before, this might not be a problem. The crankset itself is almost new. It has been mounted on some bottom bracket before and used, but not much overall. Basically there's no wear to the taper on cranks. So I'm guessing this will help with adapting it to whatever taper is available.
I have to say, I dislike trying to force things on to make them work. The tolerances when it comes to various bicycle components standards might not be quite as tight as in spacecraft construction, but I do like having parts that are a fairly close fit. I have now ordered a spindle that was most likely designed to go with this crankset and probably take it from there. One of the people selling these SR Royal spindles sent me their measurements and they don't quite match (but ae close), so I guess in a few days I should be able to just compare both spindles.
Thankfully, the frame won't be worked on before Autumn. I did have a look at an option of having the BB shell threaded to 1.37x24TPI and that is £120, which considering other costs (frame repairs and re-painting) makes it not a very cost effective option

3alarmer 

...just in passing, I thought I might mention to you that this sort of large bore, aluminum casing for a sealed BB unit is exactly the kind of thing that damaged the Ron Cooper frame I showed you as an example.

The old sealed unit I removed looked like this:




The original concept was OK, but the execution using aluminum that rides in such close proximity to the dissimilar steel BB shell lends itself to accelerated corrosion in wet environments. I suppose you could make it work better with drainage holes in the shell, but I threw this one away.

Good luck with your project.

VintageSteelEU

The BB shell Nadax was sitting in has a hole underneath, so I'm guessing that saved it from galvanic corrosion. It actually came out quite easily. When I saw the worn out nothces on it up close, I was sure I'm in for some struggle and was pleasantly surprised. Interesting removal method with yours. Wouldn't work with Nadax though, DS is fixed. On the bright side, if it's aluminium, there's always the option of deploying caustic soda against it.
I think many designs in cycling are made with pro racing in mind, where components are not planned to be used 30 + years later and throughout this period. They used aluminium probably because it's easy to work with and lightweight, so made sense. Not that great on the frames In the long term.

This project is going to be quite a money sink anyway. I'd rather get another C5 frame in my size if that was an option, that would definitely be cheaper. I do have enough parts to probably put 3-4 good bicycles of various types on the road, though for this particular one I'll be getting some more components. And another saving grace is that I build my own wheels.

mpetry912 

exactly right. nobody building these bikes 30-40 or more years ago imagined that people would still be collecting and preserving them in CY 2023.

put another way, I am skeptical that the current crop of all carbon, electronic shifted bikes will be rideable 20 years from now !

But what do I know ?

/markp

repechage

Electronic shifting, the single speeds of the 2040’s

VintageSteelEU

In 2040 we might have neural link or brain waves shifting, who knows If I'm still around then, I think I will be still happily using Suntour derailleurs with friction shifting.

Looks like I found Swiss IRD cups in a shop within the EU. So I'll get a set just in case whilst I'm trying to figure out a spindle. Combined with checking whether any Miche or Tifosi cartridge type bottom brackets are compatible. I have Sakae Ringyo Royal in 112 on its way, though I expect this won't be the correct fit for the cups I have as it's not from a 70mm BB. Other ideas to try are Sugino MW-70, though that is 114mm, and Campagnolo 70-SS, which I think can be 111 or 115mm.