Front fork maintenance, rusty steering bearings

Just wanted to share this. I got my front fork serviced this week, new fork oil + seals as well as new (conical) steering bearings as there had been some play in the front fork for a while now. First time ever that the bill was actually in line with what I had expected at 300€ but I digress...

The mechanic kept the ball bearings to show me. The top ones were pretty much fine, but the bottom ones were completely rusted. Shame I forgot to take a picture but it actually looked worse than this random pic from google (not even the same bearing type but just to make the point):

[You must be registered and logged in to see this image.]


The mechanic wondered whether the factory forgot to put grease on them or whether I had used a high pressure cleaner on the bottom of the steering stem. This I obviously didn't so (I only use a garden hose and even then don't point it at insensible parts like the ECU or bearings, but the previous owners could have done so) but considering the things I read about stingy grease usage by Moto Guzzi I suspect the former may be more likely.

On another note, the mechanic unfortunately sheered in half the clutch microswitch that allows the bike to start in gear with the clutch pressed, which I only noticed while riding home. Unfortunately the OEM switch costs like 100€, absolutely insane. Does anyone known an alternative source for the microswitch that doesn't cost me an arm and a leg (I'm not going to claim it at the workshop in these times of hardship).

motor-timothy wrote:

On another note, the mechanic unfortunately sheered in half the clutch microswitch that allows the bike to start in gear with the clutch pressed, which I only noticed while riding home. Unfortunately the OEM switch costs like 100€, absolutely insane. Does anyone known an alternative source for the microswitch that doesn't cost me an arm and a leg.

I replaced one on a Cali 1400; it was a SPDT type. I used a Burgess VL4S.

Whether the GRiSO uses the same one, you might want to compare parts lists.

Sadly I threw mine out together with the controls as ran out of space.......As a cheap alternative (especially if you are doing the clutch fluid, or switching to different controls)....replace the clutch line bolt at the handlebar with a pressure switch and wire it in....costs buttons.

[You must be registered and logged in to see this image.]

Thanks! Through rigorous searching I found a direct replacement!

[You must be registered and logged in to see this link.]


Since only the 'Actuator' part its broken I only ordered that, should work out and at <15€ including shipping and tax not too bad.

Thanks for the Radio Spares part number. I've noted this should my GRiSO ever require a replacement.

Questions on short cut fork maintenance. I have seen on forums that a quick way to improve stock fork performance one can pull the caps and drop the oil in each leg. Simply utilize a container to catch all the dumped fluid in each leg to get exactly the same amount back into each leg. First question relating to shortcut: #1 is there a fluid or flush safe to spray down into fork leg to help clean internals and there oil pathways? #2 to refill to factory spec what is the actual amount in milliliters of fork oil with (all) internals still in side fork tube? Thanks....

I wouldn't 'flush the internals' with anything (except fork oil if I absolutely had to) as it may just dilute what's in there ie may not come out- assuming you aren't dis-assembling it. There shouldn't be any major deposits to flush anyway.

The fork capacity stated is in the workshop manual but nobody gets near that number just draining in situ (more likely to get around 350ml out).

For refilling there are lots of threads about putting less oil in than factory & using lighter (5W) oil....others may be able to share experience on ride quality impacts

[You must be registered and logged in to see this image.]

Copy that Paul. Thanks

As you cannot fully empty the fork without a complete strip, I use the millimetres from the top figure on normal fork oil changes as per the manual clip below - and yes 5w was better for me
[You must be registered and logged in to see this image.]