Italian threaded....... Headset?

[Mike Muz]

Hi all

Today I am mainly recovering from a hundred + kilometer ride yesterday on my lovely Eddy Merckx bike.
In looking for a headset for my Peugeot frame, I came across one with an Italian thread. I didn't realise there were different threads. Can someone please enlighten me or even better let me know if they would be compatible?

Thank you

Muz

 

[Canuk]

It's probably French threaded if it's older than 1988, 25x1 .

 

[Mike Muz]

The frame is from around 1992/3

 

[LondonClassic]

I think the crown race size is the crucial part. According to Sheldon the angle the threads are cut at is 5 degrees shallower than ISO (60 degrees). What does this mean in practice? Very little, as long as you're not using steel threaded headset parts. You might face slighly higher resistance when threading onto the fork. I have ISO and JIS threaded headsets on Italian frames with no issues at all. Going the other way should present no dramas, esp with aluminium headset parts that are going to yield to the will of the ISO steerer thread (by '92 all Peugeot steerer threads would be ISO).



Someone will be along in a minute to tell me I'm wrong so you might want to wait for that crucial 2nd opinion

 

[Mike Muz]

Great, thank you!

 

[Rod_Saetan]

What they said

ISO and Italian are interchangeable, except the crown race can sometimes need a bit of fiddling.

 

[juvela]

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the difference between ISO/BSC and Italian is five degrees of pitch

one is 55 and the other 60


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