Fork oil question

[ralphy]

Advice please!

I've got a set of new springs to be installed in my F650GS Twin and according to the package they require 190mm of oil in the forks: but is this measured with or without the springs in?

TIA.

R

 

[Smythson]

Haynes does it with the springs in, still worth double checking with manufacturer of springs as the recommendation for BMW spec is 100mm...

S

Just out of curiosity - which springs did you go for?

 

[ralphy]

Haynes does it with the springs in, still worth double checking with manufacturer of springs as the recommendation for BMW spec is 100mm...

S

Just out of curiosity - which springs did you go for?

The springs are Yacugar Progressive Springs SP-BM08-SSA013 but I've just done a Google search on the code and that brings them up as Hyperpro...

The label quotes 180mm or it could be 190mm - printing on the lable is a bit blurry!

R

 

[Smythson]

They merged so part numbers should carry across.

I was gonna suggest looking at Dave Ett's write up but his was for the 800

Best of luck,

S

 

[curiousexplorer]

oil

Hi, Ralphy,
Our f650gs's take 500ml per leg. As you are about it, put a set of Intiminators in! Great mod/improvement.

 

[The Prospector]

Fork oil measurement is usually done with the springs in as otherwise when you drop the springs in they displace the oil at best filling the tubes to the top and at worst causing it to overflow, either way your forks cannot compress without forcing the oil out of the weakest point (the seals).
Measuring the level is usually taken as being more accurate than measuring the oil quantity in balancing the damping of both tubes. Use the best quality of oil you can afford, quality racing oil damps better than cheaper oils for a given weight. IMHO.

 

[ralphy]

Hi, Ralphy,
Our f650gs's take 500ml per leg. As you are about it, put a set of Intiminators in! Great mod/improvement.

I'm just off to Google them, having never heard of them until now.

Fork oil measurement is usually done with the springs in as otherwise when you drop the springs in they displace the oil at best filling the tubes to the top and at worst causing it to overflow, either way your forks cannot compress without forcing the oil out of the weakest point (the seals).
Measuring the level is usually taken as being more accurate than measuring the oil quantity in balancing the damping of both tubes. Use the best quality of oil you can afford, quality racing oil damps better than cheaper oils for a given weight. IMHO.

Thank you for that. The springs came complete with Yacugar oil so I'll be using that. Also, I've discovered that Motorworks supply the same springs so I'll be getting in touch with them for details on measuring the level.

R

 

[ralphy]

Update.

Spoke with the suppliers this morning and the sequence is:

oil out
springs out
full compression
fill to 190mm short of the top
springs then back in

R

 

[freelancer2011]

Ralphy, will you be using 7.5w oil by any chance? I'm going to be changing the oil in mine soon and wondering if you moved-up to something like 10w for the progressive springs?

Cheers,
Lab.

 

[ralphy]

Ralphy, will you be using 7.5w oil by any chance? I'm going to be changing the oil in mine soon and wondering if you moved-up to something like 10w for the progressive springs?

Cheers,
Lab.

I'll be using the Yacugar oil that came with the springs and that's 10w.

R