Fork oil.

[2wheelieadv]

Do you change fork oil based. on time of mileage?
Also which weight is coming from the factory? Would it be ok to have 5w for a smoother ride over NJ bumpy roads?
Thanks.

 

[Erci]

Factory oil is Yamaha 0, which really equates to 5wt from aftermarket manufacturers like Maxima (very good oil).

What does the manual say about fork oil change intervals?

For relaxed street riding, I'd check it once every 2 seasons or ~12k miles. When it comes to fork oil, unlike motor oil, I trust its smell and color. If it looks nice and clear and does not smell fishy, I say it's till good.

So.. easy enough to pour a bit out and check. If it looks good, I'd put it right back in.

As for smoother ride.. that will be difficult to achive with stock fork. Since damping is not adjustable, both legs use same oil for rebound and compression. If you go with thinner oil, you'll have less compression damping, which will absorb small bumps better, BUT.. it'll also be bouncy like a poto-stick and will dive even worse under braking. Heavier oil will give you better rebound damping (less pogo) and won't dive as much, BUT.. it'll be more harsh over bumps.

Having said that, most people over 150 do seem to like heavier wt oil on these bikes.

 

[oldfast007]

If it helps, I just changed mine to a 7.5 wt oil, definite improvement! Was dirt simple to do:thumbup:

 

[2wheelieadv]

If it helps, I just changed mine to a 7.5 wt oil, definite improvement! Was dirt simple to do:thumbup:

Is there a drain plug, or it has to be pumped out?

 

[Carlos840]

Is there a drain plug, or it has to be pumped out?

Neither, you have to remove the forks, remove the caps and dump it from the top.

I use 10w and it really helps a lot with dive under braking, without making things uncomfortable.

 

[Erci]

Neither, you have to remove the forks, remove the caps and dump it from the top.

I use 10w and it really helps a lot with dive under braking, without making things uncomfortable.

One of those times when I prefer upsides down forks.. can service them one leg at a time (not that it's a huge deal to slide both legs out at once).

 

[FinalImpact]

We did MxGolf's last night. New springs 0.85kg/mm and 10wt. Just a bit of metallic grey/silver in the oil (07 w/ ~15,000 miles)...

I mention this as one leg had 100ml less fluid than the other and he bought the bike new!

I think it took 465ml per leg to met the Fill Level of 134.0 mm (5.28 in) with the collapsed fork and no spring.

Another observation is this: Although there is no requirement in the FSM about when to change the fluid; like brake system, the fork oil breaks down as moisture accumulates. Granted its in a "sealed enclosure", moisture gets and allows componentes to rust and fluid to deteriorate.

It is my suggestion that fork oil be done in the first 5000 miles to remove the initial wear in particles and then every 2 - 3 years to keep the fluid fresh or 20,000 miles. If these were evacuated and filled with nitrogen, the moisture may be less of an issue.

 

[FIZZER6]

If you are going to change the oil for the first time on a bike that is close to 10 years old you might as well change out the fork seals and the dust seals. My dust seals have some small cracks in them and my bike is stored in an air conditioned basement most of the time.

 

[oldfast007]

Lest I forget to mention, pump a few rounds of new fluid to flush the forks prior to final fill and re-cap!:thumbup:

 

[DeepBlueRider]

Do you change fork oil based. on time of mileage?
Also which weight is coming from the factory? Would it be ok to have 5w for a smoother ride over NJ bumpy roads?
Thanks.

I'm getting all my bikes to one of suspension gurus in the area. They do initial setup for me (sag, springs, preload, geometry).

After that, whenever something feels goofy. I'm using Maxima fork oils. I might change it to Belray brand.

If i don't feel anything strange from forks, I'm changing fork oil annually anyway.

When it comes to oil weight I'm putting Maxima 20W. But don't take my word on it. Other members has raised very good concerns using so heavy fork oil in other fork oil threads, but it seems to work for me (or I'm just ignoramus to notice otherwise).

Couple side notes:
1) on FZ6, I've rode for a one year after fork oil change and everything seemed to be fine. I've change it afterwards, then after 3 or 4 months it started to be soft and dive again (during change it was liquid like almost water), so I've had to change it again. FZ6 is mine main fun bike and commuter.
2) On our SV650 fork oil survives only 5 trackdays.

 

[2wheelieadv]

Put 7.5 wt. Feels much better.

 

[7UPyours]

Unless I missed it, wasn't there a how-to for fork oil change, including removal of forks.

 

[TownsendsFJR1300]

Well, I changed my fork oil (stock forks/ springs, etc) after almost 19,000 miles.

I've never had an issue with the front end (not many twisties down here) and kept it stock.

What came out was pretty nasty, very dark green, pretty thick and started smelling like old rear end, 90wt gear oil.. Good news was, no metal "silvery" at all..

I did buy an extra quart for flushing purposes if needed and yes it was. I used almost a full quart (for both legs), flushing and re-flushing until all "gray matter/sludge" was out. You could feel a definite improvement just at the end of its travel, no sticking what so ever once done.

As noted, as I had no issues with the front end (and wanted the same feel as stock), I opted for Maxima 7wt, racing fork oil for replacement. I ended up topping off, etc, fluid just with measuring. A long screwdriver, with masking tape marked at the 134mm lenth worked perfect... Just poke it down, until the oil begins to wick and check you mark. Easily within 1 MM..

As a side note, I gave the brake calipers a quick spray down with brake cleaner while they were off the forks. After the road test, I found them to be dragging somewhat more than normal. Maybe 2 rotations vs my 3.5 to 4 rotations. I ended up pulling them again and the pads. Pumped out the pistons some, a bit deeper cleaning, re-grease and test. 4 plus rotations now :thumbup:..

Back to the forks. With the 7 wt oil in there, the ride was NOTICABLY SMOOTHER. I went out of my way to find bumps and the front end soaked them up and re-bounded like there was never a bump in the roadway... I was very surprised how much better they felt..

Even if you have the stock forks, don't put off the fork oil change. It is well worth the time and extra $ to flush them as well... :thumbup:


As a side note, thanks to FI and Erci for confirming my request (PM's) for opinions re the oil..