15W Fork Oil. Does it make that much difference?

[Dcock]

So i hate how spongey the forks are, will changing from 10w oil to 15w oil make a reasonable amount of difference? Or do i really need new springs?

[Punkstig]

Both, just oil is a cheap fix, but not as good as replacing springs too!

[darrsi]

Yes, yes, yes it does make a big difference.  :thumbup

[neil2do]

i put 15 in mine but i found it a bit hard so removed 100mm and replaced it with 100mm of 7.5 works a treat.

[JZS 600]

I've never found out how long fork springs are supposed to last for. The bike has progressive springs in as standard so what would be the difference swapping them for other progressive springs etc.

I would imagine the oil would get buggered over time though

[kebab19]

Japanese springs usually last a long time, I would estimate they'd only change a couple of mm in 50000 miles or possibly the entire lifetime of the vehicle

I think changing fork oil should be done reasonably often, i go for every 2 years or 10000 miles, whatever comes sooner. I realise others never change theirs as its 'non-scheduled maintenance' according to Mr Haynes

[Dcock]

right i think i'll have a go at changing the oil when i get some spare time then. Thanks.

[darrsi]

right i think i'll have a go at changing the oil when i get some spare time then. Thanks.

Make sure you read the correct oil level for your 98/99 bike, it's different from 00/01 bikes or later. 

[Dead Eye]

Yeah... I probably should have remembered that before doing mine... ah well, I'll just hope for the best

[darrsi]

Very nearly caught me out 'cos i swapped my forks for the older type.
It's natural to look at things in the manual for the year of your bike!

[adeejaysdelight]

I put 15W in my bike 18 months ago. I think the difference is astounding. And for that kind of money, its a well worth while job.

[Jbizzle]

I put 15W in my bike 18 months ago. I think the difference is astounding. And for that kind of money, its a well worth while job.

Hi all,


Apologies for dragging up an old post, i was going to do the 15W oil change this weekend, how many liters of oil should i buy?  I can find the air gap values, but cant seem to to find how much that translates to in ml in each fork?


just need a rough idea, no point buying loads if i don't need it, or get halfway through and realise i don't have enough!


Thanks,

[Dave48]

You wont need more than 1 Litre of fork oil. The actual amount needed per side is mentioned in the Haynes or workshop manual-check the downloads section on here. From memory its 400 AND SOMETHING ml per leg-actual amount varies with model year of forks fitted.

[Jamieg285]

1 litre should do it, but there isn't a lot to spare, so don't spill any.

[daviee]

475 cc for 98 and 99 ,, 2000 on 465cc per leg

[darrsi]

Best way is by measuring the air gap at the top to make sure they're both even.

[celticdog]

Best way is by measuring the air gap at the top to make sure they're both even.

[darrsi]

[quote author=darrsi link=topic=9569.msg255538#msg255538 date=1489517344]
Best way is by measuring the air gap at the top to make sure they're both even.

[/quote]


You need to be careful showing that picture because the air gap and oil levels are different for forks without adjusters compared to ones that do have them.




98/99 models (without fork adjusters on top):
475cc oil
121mm air gap


00-03 models (with fork adjusters on top):
465cc oil
132mm air gap




Just for the record, i am of the opinion that the fork adjusters do absolutely sod all.
When i had them on my forks they were always screwed right in to attempt to firm up the front end but with little effect.
Due to another issue i changed my forks for an older set that didn't have adjusters on then put the 15w oil in and there was a very nice difference as far as handling was concerned, and it was so suitable for me that i just didn't bother swapping the adjusters back over.
If you ever change the fork oil then upgrading to 15w is a small mod that i would totally recommend without any doubt, that can improve the front end handling of the bike for no extra cost.

[Jbizzle]

You wont need more than 1 Litre of fork oil. The actual amount needed per side is mentioned in the Haynes or workshop manual-check the downloads section on here. From memory its 400 AND SOMETHING ml per leg-actual amount varies with model year of forks fitted.

Thanks Dave!

[Jbizzle]

1 litre should do it, but there isn't a lot to spare, so don't spill any.

Thanks Jamie