4 replies [Last post]
Frenia
Frenia's picture
 Offline
Joined: 07/31/2017
Posts: 17

Hello,

I am about to mount the rear swing arm on my R50 and want to chase the threads for the pivot.

The outer diameter of my pivot pin threads is 19.8 mm

Will this be an M20 tap (x1.5) ?

Thanks!

Frenia
Frenia's picture
 Offline
Joined: 07/31/2017
Posts: 17
(No subject)

Link to a pic of the threaded whole for rear swingarm

schrader7032
schrader7032's picture
 Online
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6991
Are you talking about #11

Are you talking about #11 here:

https://www.realoem.com/bmw/enUS/showparts?id=0211-EUR-01-1956-T50-BMW-R...

None of the online sites lists a size. But if you measured ~20mm across the threads of the pin, then it sounds like it's M20. To find the pitch, you would use a pitch gage or get a micrometer and measure the distance in mm across say 10 peaks (pick one thread peak, count 10 more thread peaks from that). That will give you mm per thread.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Frenia
Frenia's picture
 Offline
Joined: 07/31/2017
Posts: 17
Hi, Yes,it is part #11 I used

Hi,
Yes,it is part #11
I used a gauge and the threads are definitely 1.5.
I’ll order M20 x 1.5 and post back if it fits.

Frenia
Frenia's picture
 Offline
Joined: 07/31/2017
Posts: 17
Hello, I can confirm that the

Hello,

I can confirm that the proper tap is M20x 1.5. Just installed the swing arm after chasing with this tap.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.