FORK OIL CHANGE

[sTe140Ve]

I want to fit progressive fork springs to my '99 885i which looks easy enough. I want to change the fork oil as well but I can't see a drain plug anywhere. Do I really have to take the forks off the bike to change the oil?

[Chris Canning]

YES

If you check there are heaps of postings about forks.

[Danny955i]

+1!

Yes, and if the bike is over 5 years old, it's a good idea to do it anyway. Lots of condensing and expanding of air, lots of condensation, and lots of metal sludge can build up in the forks over the years.

My bike was ridden for 1000 miles and PARKED for 8 years. At 3000 miles I changed the fork oil and I'm glad I did... It was GROSS.

I suggest running a slightly THINNER oil if you're going to do a lot of trail/off road use... 5w.  And thicker oil if you're going to do a lot of road riding... 10w or even 15w. Make sure you use FORK oil and nothing else.

If you wanna get 'stock' oil (7w) you can just buy 1 quart of 5, and 1 quart of 10 and mix them together VERY well... then go from there.

I think the Progressive springs are my next mod. Lemme know how they feel!

[iansoady]

I still don't know why they couldn't just fit a drain plug....

[Mustang]

I still don't know why they couldn't just fit a drain plug....

because it saved a few pennies during production and.........................the average joe is going to take it to the dealer for fork service now that it is not easy for him to change oil in the forks . Dealer wins with increased charge for fork service .

[ChazzyB]

The way I look at it, is, as the forks need to come out to set the correct air gap when refilling, what's the point in having a drain plug at the bottom?

[jwray76]

The way I look at it, is, as the forks need to come out to set the correct air gap when refilling, what's the point in having a drain plug at the bottom?

Now this is just silly. Of course you can check the amount of oil with the forks on the bike. There would just be another method, which could be added to the manual.

[jwray76]

I still don't know why they couldn't just fit a drain plug....

because it saved a few pennies during production and.........................the average joe is going to take it to the dealer for fork service now that it is not easy for him to change oil in the forks . Dealer wins with increased charge for fork service .

May be true but sounds like a bit of a conspiracy theory. I think it has more to do with the average joe never even thinks to change fork oil.

[ChazzyB]

The way I look at it, is, as the forks need to come out to set the correct air gap when refilling, what's the point in having a drain plug at the bottom?

Now this is just silly. Of course you can check the amount of oil with the forks on the bike. There would just be another method, which could be added to the manual.

Please do tell!

[Chris Canning]

I still don't know why they couldn't just fit a drain plug....

because it saved a few pennies during production and.........................the average joe is going to take it to the dealer for fork service now that it is not easy for him to change oil in the forks . Dealer wins with increased charge for fork service .

+1

The forks just like the rear shock are bargain basement.

[ChazzyB]

I still don't know why they couldn't just fit a drain plug....

because it saved a few pennies during production and.........................the average joe is going to take it to the dealer for fork service now that it is not easy for him to change oil in the forks . Dealer wins with increased charge for fork service .

+1

The forks just like the rear shock are bargain basement.

They may well be. But do any forks these days have drain plugs?

[jwray76]

The way I look at it, is, as the forks need to come out to set the correct air gap when refilling, what's the point in having a drain plug at the bottom?

Now this is just silly. Of course you can check the amount of oil with the forks on the bike. There would just be another method, which could be added to the manual.

Please do tell!

Umm like bike on center stand or aux. stands measure to a certain level. Of course there is always the replace what you remove method as long as there hasn't been a leak.

[Timbox2]

Come on guys, dropping the forks aint no big deal, I left mine upsde down overnight, but actual spanner time was 1.5/2 hours tops, and you do need to cycle the forks a fair bit to get all the crap out and then again to get rid of the air, not so easy if they are still on the bike

[ChazzyB]

Come on guys, dropping the forks aint no big deal,

Agreed. I wouldn't like to try to measure the air gap with them in the bike. The wheel at least would have to come out, as I can't see compressing the forks with it all still installed would be easy.

Replacing with same amount of oil removed: Yes, a leak would scupper that, as would the wrong amount having been put in last time. I assume the factory quoted oil capacity is for a dry fill. I have a recollection that I worked out for another bike, that once the bulk of oil was in the forks, a single cm3 of oil added or removed equated to approximately 1mm of oil height. But maths was never my strong point. ;-)

[iansoady]

But if you have the front wheel in the air (ie forks fully extended) and the springs out then you should have a repeatable position so an air gap measurement should be consistent.

OK I'm what some people here & elsewhere call the wrong side of 45 (actually I prefer to think it's the right side) but if simply draining the oil out of the engine sump, where it's had a far harder life, is OK, I can't see why it shouldn't be so for the forks.