Forks questions ....

[georgesgiralt]

Hi Lads,
With some friends on a French airhead forum, we discussed a lot about forks on our machines.
Someone argued I did not put enough oil in it. And advised to use a thin rod 60 cm long, insert it at the upper hole and measure the level attained by the oil in the fork.
Problem is that I can't insert more than around 45 cm of it into the fork, and thus, the rod comes out dry and clean...
Question : Do someone use such a method to measure the level of oil in an R65 ? And how ?
Another question, It seems I've too much sag. But I forgot to measure the length of the springs when I had the fork dismantled...
Do you have a method to remove the springs when the fork is in place, because I can't access the fork tube because of the handlebar and the brake tubing. Add to this that I've difficulties compressing the spring enough to remove the stopping ring...
Thank you all for your advice and help !

[Barry]

Hi Lads,
With some friends on a French airhead forum, we discussed a lot about forks on our machines.
Someone argued I did not put enough oil in it. And advised to use a thin rod 60 cm long, insert it at the upper hole and measure the level attained by the oil in the fork.
Problem is that I can't insert more than around 45 cm of it into the fork, and thus, the rod comes out dry and clean...
Question : Do someone use such a method to measure the level of oil in an R65 ? And how ?
Another question, It seems I've too much sag. But I forgot to measure the length of the springs when I had the fork dismantled...
Do you have a method to remove the springs when the fork is in place, because I can't access the fork tube because of the handlebar and the brake tubing. Add to this that I've difficulties compressing the spring enough to remove the stopping ring...
Thank you all for your advice and help !

Hi Georges,

I've used the dipstick method to check the oil level for 18 years and have never had a problem with access. The tip of dipstick will rest on top of the damper piston and there shouldn't be anything in the way of it reaching down through the centre of the spring. The measurement range I have is between 20mm and 50mm of oil on the dipstick. varying the amount will tune the forks response by it's effect on the "air spring"

To remove the springs with the forks in place I simply rotate the handle bars, brake master cylinder  and brake lever out of the way. 

To remove the locking ring, I leave the oil filler Allen screw in place. I insert an Allen key in the filler plug and then press down on the plug with a large screw driver with one hand, the other hand then rotates the Allen key until it jambs under the handle bar and holds the plug down. I then have both hands free to remove the ring.  The Allen key I use is dedicated to the job having been shortened so it will fit under the handle bar and a rubber sleeve is fitted over the long arm so the it grips under the handle bar and doesn't slip out.

Having said all that, if you are having difficulty depressing the plug, I doubt the springs can be much  be too short.

[georgesgiralt]

Hi Georges,

I've used the dipstick method to check the oil level for 18 years and have never had a problem with access. The tip of dipstick will rest on top of the damper piston and there shouldn't be anything in the way of it reaching down through the centre of the spring. The measurement range I have is between 20mm and 50mm of oil on the dipstick. varying the amount will tune the forks response by it's effect on the "air spring"

Hello Barry
Yes, the rod goes easily into the spring and sit (I think) on top of the piston. But the oil level is lower than that as the dipstick comes out dry. So either the 190 cc oil BMW recommend is too low in volume, or my rod is not going down as much as needed...  Could you tell me the length of the dipstick you use ? and tell me where approximately it ends (seeing from the outside ? )
 

To remove the springs with the forks in place I simply rotate the handle bars, brake master cylinder  and brake lever out of the way. 

To remove the locking ring, I leave the oil filler Allen screw in place. I insert an Allen key in the filler plug and then press down on the plug with a large screw driver with one hand, the other hand then rotates the Allen key until it jambs under the handle bar and holds the plug down. I then have both hands free to remove the ring.  The Allen key I use is dedicated to the job having been shortened so it will fit under the handle bar and a rubber sleeve is fitted over the long arm so the it grips under the handle bar and doesn't slip out.

Having said all that, if you are having difficulty depressing the plug, I doubt the springs can be much  be too short.

Good idea. I did not though about using an Allen key to jam the fork plug.
My problem is not the spring being too hard, it is my arm being too feeble. Age took it's toll and lack of mechanic practice no not help.
But I'll give your method a try !
HAve a nice day !

[Barry]

After trying a long steel rod, the dipstick I regularly used was the one from my car because the clean oil was easier to see on a proper dipstick. I've recently sold that car so I wouldn't be able to give you a measurement without doing the job myself. After  measuring  450mm on the exterior of my forks I would say that dimensions seems correct though. Hopefully the dipstick on the new car will work.  Give me a day or so and I'll try it. 

I found 190cc to be correct for an oil change but the volume for a dry fill is a little more, I'd be inclined to add another 10 or 15cc