Forks oil x Dakar, advice needed
 

Hi,
I need to repair a leak on one of the front forks (650 Dakar-year2005).
I'm in Asia.
I have no idea what oil I need and wich are good alternatives to the factory one that I may be able to find around here.

Also, I would like to have a higher grade (possbly 15) to increase damping and decrease forks diving.

Any suggestions?
Any experience with different oil brands / viscosity / performance?

Thanks

DD

forkoil...
 

Hi, how are you??
Any known brand of forkoil will do the job. What grade are you using now? If you change to a higer grade, the fork will be slower up and down. So, if you ride on corrugated (?) roads more of the vibrasjones will go to the bike.
On my r80gs I changed from 10W to 5W and it was a big different.

Is the simmerring broken? It might just be dirt, so maybe its worth a try to clean it whit a thin feelerguage (0.10mm)
Hope this help... good luck

No foil oil?
 

If you cannot find fork oil ... then

Auto transmission fliud will work ... to get you going on to somewhere where you can find fork oil. It is about 5W.

Any car/truck place that repairs suspension shocks will have the right stuff ... you'll need to ask and wait while they find the stuff you need .. they are doing you a favour so be curtious.

This applies to my '05 650GS.

I'm told it came from the factory with 7.5 weight. I did not like the nose dive when applying front brake so I upped it to 10 weight (belray brand). That worked great.

Just upgraded my rear suspension and changed my front springs to the progressive Touratech springs. Per their instructions, I added 15 weight. If it rattles my cage too much, I move back to 10 weight. I asked around about best brands and never got the same answer. They're probably all about the same. Go to www.f650.com for good information. Best of luck!

Heavier fork oil?
 

Be very careful when changing from 7.5W to 15W (read: don't)
While your forks will definitely dive less on the brakes with harder damping you will also make the fork stiff causing the wheel to lift off and just as worse to bottom out on bad roads and dirt roads.
IMHO the original damping of the F650 GS and Dakar is already too hard for bad tarmac and gravel (being set up for high speed stability) causing the bike to feel unsettled and indifferent under rough conditions. This will get even worse with heavier fork oil. Cornering hard and fast on bad tarmac will reveal an overdampened front end immediately by lack of steering precision (difficult to keep the line) and increased kickback tendency (more notable on road bikes with wide front tires)
The only clean solution to get rid of too much nose dive of a bike is getting aftermarket fork springs with more progression.
Pressuirizing the fork (where possible) does work as well as decreasing the size of the air chamber by adding more oil (very carefully, not more than 10 mm in one go). A lot of pressure or a significantly higher oil level will affect the lifetime of your fork seals.
Very important: Fit fork boots if you don't have them already. It's a joke that a bike like the Dakar comes without them.

Re:GSing. It's quite unusual to see Touratech recommending heavier oil for their progressive springs. Most manufacturers go with the original viscosity or recommend even lighter oil to improve the response of the suspension (see yngveer) unless the original setup is seriously underdampened.

For fork oil you can use ATF (Automatic Transmission Fluid) which comes from every car / gearbox workshop and is usually 7.5W. It was filled into motorcycle forks before the advent of specialised fork oils and works fine:-)

Alternatively you can use hydraulic fluid but it is only commonly available in quite heavy viscosities (20W and heavier). Lighter hydraulic fluids like 5W and 10W are available in cold and arctic climates and in the fork lift of the nearest commercial cold storage:-)

Check your inner tubes very carefully for stone dings and smothen them out with a very fine oil stone followed by a nice polish. On young bikes oil leaks are usually caused by stone ding damaged inner tubes.