reconnaissance

This Bianchi is from 1993, all Tange tubing and I believe was built in Japan. Is the bottom bracket Italian threaded?

SJX426 

@reconnaissance - Measure the bb shell width. 68 is English (likely), 70 is Italian.

Attractive bike, BTW!

jiangshi

I guess it would be too difficult to just read the markings on the bottom bracket?


But an Asian Bianchi is most certainly English threaded.

Bianchigirll 

English. FWIW that is a '93 model and came with Ultegra 8spd STI

joesch

Nice FG/SS conversion. Are there any spacers on the rear axle for best alignment ? Is it a flip/flop for FG/SS ? Looks like a fun ride but would be a challenge in the TX hill country.

Bianchigirll 

Actually this frame is a very poor candidate for a SS conversion due to the vertical dropouts.

joesch

Is not this the case for most all road bike conversions to a SS?
I agree it is best to have a track frame for SS bike.

conspiratemus1

Previously, I would have said, if asked, that I wasn’t partial to colour breaks at the lug edges (chromed lugs excepted.)
I just changed my mind. Wow.

reconnaissance

I’d be the first to agree with you except the chain “slack” is perfect for the gearing I’m using.

Bianchigirll 

Not on older frames with horizontal dropouts especially the longer style more common before the late '70s

joesch

Thanks for the schooling . I was not aware of all the variants and that the track is "Not a dropout" but a forkend.

Bianchigirll 

Your welcome and this is just a condensed reference. There are a few more but mostly variations on the basic.

JohnDThompson 

As @Bianchigirll notes above, an Asian built Bianchi should be English thread. And as @jianshi notes, the bottom bracket cups should be marked with thread type: 1.37 x 24 for English, 36 x 24 for Italian.

N.B. shell width (e.g. 68mm versus 70mm) should be seen as an unreliable indicator of thread spec. More than a few Japanese production bikes were made with 70mm shells and English thread.

conspiratemus1

I have a couple of old BBs that just have code markings stamped on them. If you didn't know the code, you wouldn't be able to tell the threading just by looking at the cup faces, especially if the shell width was a false flag.

jdawginsc 

Had the opportunity to be tricked on a 70mm english thread guy...might have been a late 80s KHS, I think? It was a booboo at the Taiwanese factory apparently and a cool bike, but I didn't take the plunge.

I would imagine they had to use an Italian cartridge with English cups?

79pmooney

Bianchigirl is right. Horizontal road dropouts rule for road fix gear or single speed use. (Track ends are great on the track and work on the road but removing/flipping wheels is more work.)

BB threading - almost certainly left the factory as English threaded BUT any bottom bracket can be re-tapped to the larger Italian. That has been done many times when the original threads were damaged. Shops keep Italian taps just for that purpose. That trick was old when I was working in bike shops 45 years ago. Yourt bike has had 27 years to have a threading accident.

Good thing (for identifying which you have is thread direction on the (edit: confusing) right hand (drive) side. Left hand thread - English, left right hand thread - Italian (edit: poor proof reading). (And an English BB in an Italian BB will be very loose fit because Italian is larger diameter.)

Thanks guys for waking my up.

jdawginsc 

i think you mean right hand thread for English?

jethin

Let’s make it simple: right side left hand Eng, left side right hand Ital, left side clockwise 1.37”, right side dextrorotary 26 mm. You’re welcome.

conspiratemus1

No, he means left-hand thread for English and right-hand thread for Italian. (it's only on the drive side that they differ in direction.)

conspiratemus1

Simple, but not helpful to the uninitiated because in the bolded section, there is no clue in your wording that clockwise 1.37" means English and right-side dextrorotatory means Italian. And there is no value in quoting left-side thread direction anyway, because everybody uses right-thread left cups.
Should just post a link to Sheldon Brown's pages on this and be done with it.

JohnDThompson 

No, just a longer spindle. The 70mm, English thread bottom brackets I've seen are cup-and-cone units, not cartridges. Some cartridges, e.g. Phil Wood, SunTour, use removable mounting rings on both sides, so fitting such a cartridge is simply a matter of picking the right spindle length and mounting ring thread.

jdawginsc 

That makes sense. Italian spindle with the English cups. The spindle diameters through the cup hole I assume are pretty standard other than the old French?

T-Mar

There are plenty of cases where Bianchi has bounced the manufacture of mid-range bicycles with Japanese components back and forth between Japanese and Italian sources. It all depended on the the relative values between the Lira and Yen at the time.

Also, as previously mentioned, there are cases of Japanese bicycles with 70mm shells. The boom era, entry level Sekine used 70mm shells with 68mm spindles because their preferred cups had very thick walls.

The bottom line is, if you're trying to determine Italian versus English bottom bracket threading, refer to the stamping on the cups or the threading direction of the fixed cup.

JohnDThompson 

Or, diameter of the cup: Italian cups are 36mm diameter, while English and metric (French, Swiss) are 35mm (if you want to get pedantic, English cups are 34.8mm, but round to two significant figures).

merziac

IMHO, you are being very generous giving a pass on BB thread "accidents" .

Again IMHO if a BB gets screwed up, lack of skill, experience and attention are usually the cause, sometimes tools that have been poorly used and or compromised will cause problems but the operator is responsible for recognising a problem and avoiding it before it goes too far wrong and ruins any expensive, hard to source parts and pieces.

Once the Italian thread "trick" became common practice, pressure to do it right lessened even more with a fallback kludge that adds another layer of unnecessary BS to a situation that should have been avoided in the first place.

Just sayin