shimano 6400 and 7400 headset bearing sizes?

[foz]

Velobase says 5/32" for the ultegra 6400, and 3/16" for the dura ace 7400 headset - can anyone confirm or deny those sizes, before I order some?

thanks!

 

[Midlife]

I thought the smaller bearings were for the 7600, ultegra 600 (whichever number that was) and the 1050. Related to the low stack height for the headsets, particularly the 7600.

Sort of copying the smaller bearings in the Campag Pista headset?

Shaun

 

[foz]

Shaun, the 6400 is shimano 600 It has a slightly lower stack height compared to the 7400, hence the smaller bearings... I have the catalogue info for both of them, but the actual bearing sizes aren't stated. I checked velobase, which is usually correct, and must admit that I didn't measure the old bearings yet.

I'm not even sure where to buy loose ball bearings from anymore!

 

[Midlife]

Hi Foz, I learn something new every day . All those blooming numbers!

The scans you posted sort of back up my memory that the lower stack height headsets have smaller bearings. The 7600 appears regularly on well known sites for hundreds of dollars being one of the smallest stack heights there is!

SJS sell good quality ball bearings iirc. Best of luck with the digital callipers

Shaun

 

[spitball]

Funnily enough I was looking for ball bearings earlier on eBay, just type in Shimano bearings.

 

[one-eyed_jim]

I think you're right - 3/16" for the 7400, 5/32" for the 6400.

This exploded diagram lists the 7400 as 3/16":

http://dt6110.web.fc2.com/parts/7400/HP-7400GT.jpg

and this site confirms.

The 6400 balls are clearly smaller, and again this site lists them as 5/32".

The difference in stack heights tends to confirm.

I think I've got the exploded parts diagrams somewhere on an old hard drive. I'll post them here if they show up.

 

[foz]

That's great, thanks Jim!