Newb R12S fork questions
 

I'm finally getting around to shock mods and RT A-arm on my 12S and I noticed that when the forks are extended when the front shock is removed, there is a hole in the fork tube exposed by the fork seal. What is this hole for? Factory assemby of the fork lowers onto the fork? Also, it appears that the air in the fork is also acting as a spring to extend the forks and it's more than just the weight of the front wheel, etc.. Should I be bleeding this pressure off by the top screw? I searched briefly for this subject but came up empty.

Mike;

Forks sometimes build pressure........that is one reason I have a quick bleed (push button) to relieve the pressure on the forks of my dirt bike.

So it does not hurt to remove the bleed screw in the centre of the fork cap once in a while.

It seems kind of odd that the fork tubes would drop far enough to expose holes in the fork legs.......but maybe that is just the way it is built due to using a shock for the suspension duties.

I am sure someone will chime in that has had the forks apart.

Cheers

there is nothing holding the forks together other than the a-arm and shock. that hole probably has something to do with lubing the sliders. i doubt those forks would ever get warm enough for the air build-up to influence the spring rate, but it could pop the wiper and seal. i have never bled the air on purpose

If you read the BMW manual, you're not supposed to let the forks extend to where the hole is exposed. Tie the forks to the upper ball joint bridge to support the forks from over extending.

That's what I did after I noticed the holes. My manual (Haynes) said to make sure there was no load on the shock before removal, but said nothing about releasing air pressure. I figure the worst I could have done is damage the fork seal and this will be evident pretty quickly, but hopefully I'll be OK when I get it all back together. Another reason for supporting the forks would be to alleviate tension on the front brake line which may be why some have said you must remove the banjo bolt at the fork bridge to remove the A-arm (next step), but the strap also avoids this hassle.

Between your reading the shop procedures after disassembly and my stellar financial planning acumen, the motorcycle industry should be able to weather this economy......:D

I actually did read the procedure thoroughly before and re-read again afterward. I guess my un-doing was that the rear wheel was off and so the surprising pressure in the forks rocked things back a bit on my jack (but no danger of tip-over), even though the front wheel was blocked to prevent the forks from sliding off. But you're right, if I've screwed it up, I'll be down at the dealer for more parts :D