Got a Royce Ti 73mm square taper BB which I'd originally bought for another project. Now that I've ordered a different frame, this one with a 68mm BB, is there any way of getting the Royce to fit ok, using spacers for example? Cheers.

yes – typically x2 2.5mm spacers, can be had off CRC, use them to get your chain line right

Surely no. Isn't 73mm Italian hows that going to squeeze into an English 68mm bottom bracket.

Ah good point if its going from Italian to English threads then it will not – is this a road bike project or MTB? If MTB then no prob

I had a 73 mm BB in a MTB frame meant for 68 mm – I wondered why there was a lot of thread showing. Thread diameter is tha same – its only the length of the unit that is different

Not ideal, but can be done, will have some excess thread showing at both ends as TJ says.

Italian have both the threads the same way as well(clockwise)

hmm so I could use the spacers to cover the threads that remain visible I guess…? It's an MTB project, quite a tasty one at that :-D.

Btw, Sheldon says Italian is 70mm, and 73mm is "oversized standard UK blah blah"

Put the spacers on ie x2 2.5mm and no threads will show and you will be able to tighten it up sensibly

as you say – and beat me to it!

No I'm sure you all wrong here. I run Italian and English frames the 68/73mm is the diameter they're not interchangeable. Typically a road B/B is either 68 0r 73X108.

super, cheers.

edit – hmm, I'm going to check Sheldon again…

Italian is 70, I'll shut up now.

Doesn't the 68/73mm refer to the *width* of the BB shell, rather than the diameter?

Totally lost now. My Italian b/b's don't fit my English frames the thread is too wide and conversely the 68 English ones just fall in.
But I know Campag do 68/73 bottom brackets WTF?

Most likely yet another confusing, overlapping set of bike measurement standards. My head hurts as well, it's too late for this thread 🙂

Hi Pedalhead! It's been a while.

Glad you said it oldgit. What a load of nonsense all round apart from Lionheart and TJ's offerings.

As an example all of SKF's BBs are supplied as 73mm effectively with one 2.5mm spacer to reduce the driveside length.

What frame did you go for in the end mate?

Hey Jon. Finally threw the budget out of the window & just today ordered a Singular Pegasus 8)

With regard to bottom brackets:

All English road frames are 68mm wide with a 1.37" thread (as are most MTBs). This has opposing threads on each side of the BB.
Italian road frames are 70mm wide and have a 36mm thread. These have a RH thread on both sides.
Some MTBs have a 73mm bottom bracket with opposing 1.37" threads.

Apart from the width, there is no difference between 68 and 73mm BBs. Italian (70mm BBs) have a different thread size and direction.

Now that's good choice Mark. You got there in the end!

As promised (belatedly) I'll send you pictures of my build, that's likely to be finished…..tomorrow!

For the record 68/73mm refers to BB shell width. As long as your Royce BB is 1.37"x 24tpi (as I'm sure your Pegasus frame will be) then it'll fit just fine, with the addition of one or two 2.5mm spacers.

Doh! Make that non-driveside for the spacer(s)!

Thanks 🙂 Excellent to hear your build is nearly finished at last…let's see those pics!

WTF is all this talk of spacers you nutters! If its 1.37 you can use it but you'll either have some threads sticking out (bung some lockrings on – I've got an unused pair 😉 ) or live with it. Spacers? They're for external bb's. Were talking proper bb's here chaps!

All these years thinking 70mm was Italian diameter and 68mm was English diameter. Whats always thrown me is that if it does refer to the width they are diferent diameters as well.
Bugger me.
Edit, Ah just read scmikens post, so I was right about the 68/70 side of things and was getting my knickers in a twist with the 73 ones.
That's that sorted then?

lol that is a good point, well made. Now, wtf does a BB lockring look like?

Or buy a couple of cups from Cliff – £25 I believe.

So, being a bit of an idiot when it comes to bottom brackets (oh, you'd noticed?)…presumably the *axle* on a square taper bottom bracket sold as "68mm" is the same length as a "73mm" one, it's just the depth of the threaded cups that differs..? I'm guessing the other figure quoted…113mm in this case…is the axle length.

Well not exactly 'exclusively for external BBs' but fair point regarding lockrings. Never used them myself but they do make sense.

As you say, we're talking decent BBs here!! Contemplating Royce or Phil Wood for my road bike build. I also rate SKF but they don't do a square taper 118mm.

You're absolutely correct there Mark. The axle width is the axle width irrespective! Hence the reason for putting the spacer, erm..lockring, on the non driveside as otherwise you'll bugger up your chainline.

Will do on the pics mate!