93 Orange Clockwork sizing info please

[Thejackal1971]

Good afternoon

Could someone please confirm to me both the internal diameter - for the seat tube, and the external diameter - for the front shifter please of a 1993 Orange Clockwork.

Very many thanks in advance.

 

[brocklanders023]

Re:

Pretty sure my 93 was 26.8mm internal, 28.6mm external. :?

 

[Thejackal1971]

Re:

Thank you very much. I did think that might be the seat post size, as the seat tube out of my Kona (which is stamped as 27.0mm) was a fraction too big.....

Appreciate the speed of your reply, and for the confirmation.

Now to find a period correct top pull XT front shifter....

Regards

Carl

 

[Silvergoat]

Re:

Seatpost diameter would be 26.8mm and you need to get a front mech with a seat tube clamp that covers the external diameter from 28.6mm to 31.8mm. See the following "What size seat post/front mech or bottom bracket will fit my bike?" chart at Orange:

https://www.orangebikes.co.uk/support/f ... dimensions

 

[recup]

Re:

Hi,

What tube set is your bike build with? I have a bike build with Tange Prestige Ultimate Ultralight and can't figure out the correct seatpost size.

Thx!

 

[MRGRUMPY]

Re:

As above, my 1993 Clockwork was 26.8 seatpost and 28.6 front mech.

 

[recup]

Re:

28.6mm (OD) - 26.8mm (ID) = 1.8mm

So the wall thickness is about 1.8mm / 2 = 0.9mm. Doesn't that imply a low level seat tube? I thought high end seat tubes had a wall thickness of about 0.6 mm. (SBT, thicker at the end of the BB)

Maybe I'm missing something...

 

[Silvergoat]

Re:

Yep, 1.8mm is correct. Had the vernier calipers out to check one time in order to get the correct fittings. Not sure if I'd trust my life to 0.6mm – that's just half a millimetre!

Having had the bike repowdercoated, the frame came back a bit lighter – the stripping/burn-off/blasting process before painting takes off a layer it seems.

 

[FluffyChicken]

But Prestige (ultimate ultralight) is not a clockwork.

The internal could be anything, it depends on what thickness for what job and what reinforcement they wanted with your bike.

 

[recup]

Re:

That's something I cant't understand.

For example, if you look here:
https://framebuildersupply.com/products ... length-640
The seattube ID will always be about about 28.6mm - 2 * 0.6mm = 27.4 mm. If you add external reinforcement (like in the picture below), this ID won't change...



So I can't understand why high end seattubes can have a seatpost of 26.8mm. This would mean a wall thickness of about (28.6mm - 26.8mm)/ 2 = 0.9mm. That would mean that the seattube is not butted but plain gauge?

Maybe I should make a seperate topic for this. I hope someone can clearify this...