Measuring BB and headset

Hi all,

Quickly - need to buy new bb and headset for my road bike - which I bought on here:

http://www.lfgss.com/thread80805.html

....so I need to work out what size headset to ger and if it's threaded/threadless? (do I just measure headtube diameter?)
Also need to work out bb size - will I have to take the current one out to do this?
Im new to all this and it's still quite confusing !

Thanks a million
LTR

The size of the headset is determined by the external diameter of the steerer.

No need to take yours apart just yet though: it has a quill stem, which means it has a threaded steerer, which will take a 1" headset.

For the bottom bracket, you will need to know the length of the spindle/axle, if the spindle tapers are ISO or JIS and whether it is British or Italian threaded.

Different cranks require different length spindles for a correct chainline: just measure the one that is currently fitted and/or check Velobase to confirm.

ISO and JIS tapers are interchangeable, but the equivalent spindles are 2mm different: for example cranks that need a 111mm ISO taper, will be just as happy with a 109mm JIS taper. Look at the end of the spindle: ISO have a 1mm extension chamfered at 45° on each end, which JIS don't, hence the 2mm difference.

There are two ways to determine if your BB is British or Italian:
1) measure across the frame where the BB fits (the BB shell), if it's 68mm then it's British, 70mm then it's Italian;
2) the drive side cup of Italian BB has a normal thread, so fastens/unfastens in the usual way; British BB have a left-hand thread so operate in the opposite direction to usual.

As you have a Dutch frame it will certainly have a British BB, the cranks are Shimano 600EX (check the reverse says FC-6200), which take a 116mm JIS taper BB (or 118mm ISO).

I've simplified things a little: here's a little more reading for you.

I'm sure there's a thread about this kind of thing kicking around but if not:

just from those pictures i'd say it was a 1 inch threaded headset you need. If you change the headset you might need to be careful about the stack height of the new one

if you're putting the same cranks etc back on i'd assume you'd need the same size BB. it may well say on the old BB (so you'll need to take the old one out).

bottom brackets usually have 2 numbers the first is the bottom bracket shell width (commonly 68mm or 73mm) . the 2nd is the spindle length.

this bike apparently has a Shimano 600 Arabesque groupset.
From a quick google search it would be a 68 x 116 but that's a bit of a stab in the dark.

^^ what he said.

Maladroit/scilly - thanks so much for this!! Il be back in touch no doubt when I start measuring things!!

So im pretty sure my headet is this (the Primax - 3rd pic down):

http://www.t-trader.eu/vintage-parts/headsets/

....I make it a 42mm stack height. I don't think I could go any shallower on the stack height either or il be over the bars on my arse im sure !

I also notice when looking to buy a replacement the mention of English/Italian/French threads ! Assuming I need English? This bike stuff is so confusing.......!!

Rgd the bottom bracket.......I measured my bb shell and it seems to be 68mm (well more like 66/67mm ! weird?). Now, I need to buy new chainset anyway, so im looking to buy a bundle i.e. chainset with matching bb. So I just need to make sure that the bb is British, right? (as It will deffo fit the chainset it comes with !)

Thanks again all !

Luke

If you check the last link I posted (Sheldon's threads cribsheet), you'll see that the only difference between the three is that Italian threads are cut at a slightly different angle.

In practice, this means that they are interchangeable.

The only part which isn't is the crown race (the part which fits on the forks). Chances are that your bike has a British/ISO standard headset, in common with the bottom bracket. You can get a pair of digital Vernier calipers off Ebay for less than a tenner to check.

If you buy a headset with the same type of bearing as the one on the bike (ie loose/caged ballbearings, needle roller or cartridge/sealed) and the new race doesn't fit, then you can reuse the old one.

Yes, the BB seems to be ISO: the shell could have worn or your measuring is a bit off, but you can confirm this from the fixed/drive side cup: an Italian cup will screw in normally (ie clockwise); an ISO cup will work in the opposite direction; again, check Sheldon's table for details.

You can buy BB/chainset bundles, but mostly they are sold separately so you will need to check what length spindle a particular chainset needs: it should say in the ad, check the manufacturer's website or ask the retailer.

Aces - thanks for this - will keep looking into all this and let you know outcome !
L