10W or 15W fork oil

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bobajob
Posts: 106
Joined: 02 Mar 2013 18:34
Location: Christchurch, Dorset
Location: Christchurch, Dorset

10W or 15W fork oil

Post by bobajob »

Have just got my fork stanchions back from philpotts, excellent service and what looks like a great job.

So now to put the forks back to gather. the bike is a 76 Strada. What oil would you recommend 10W? 15W?

Any advice greatly received

Bob
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George 350
Posts: 521
Joined: 16 Jun 2007 09:43
Location: Northampton

Re: 10W or 15W fork oil

Post by George 350 »

Hi,
Personally I use a 20W oil in both of my 350's. Have tried thinner, but the ride was too bouncy.
George
George
350 sport 1978, 350 Strada 1978
650 Norton 1967, 650 Kawasaki 1977 and 650 Enfield 2019
EVguru
Posts: 1530
Joined: 01 Aug 2006 11:13
Location: Luton
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Re: 10W or 15W fork oil

Post by EVguru »

That's actually an impossible question.

You can start with the fact that SAE ratings are sloppy as hell and then add to that fact that they are not applicable to fork oil. One manufacturers 10 weight can actually be less viscous than another's 5 weight. The internals are sloppy too.

So, stick to only one oil brand (prefferably something that has a data sheet available; listing an actual viscocity rating) and start with something around 15W and see if it suits you.

I've been as low as 5W and as high as 30W (which was best on track, but horrible on road).

Now doing custom internals.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
mgelder
Posts: 136
Joined: 18 Jan 2011 14:36
Location: Cambridge

Re: 10W or 15W fork oil

Post by mgelder »

I used 15W in the forks on my 350K, but they're a later design and longer travel than the original Strada ones.

A lot of it is down to personal choice, and how you ride the bike. In the seventies and early eighties we all thought stiffer suspension was better suspension, but I tend to 'ride' the front of the bike and prefer to feel what is going on; softer damping helps with this.

I'd personally start with 15W of a decent brand oil. I use Motul or Silkolene, but what you're looking for is an oil that tells you the weight - rather than just saying it's 'medium' or 'light' - and one that's available in a wide range of weights such as 5W, 7.5W, 10W, etc.

There's a Marzocchi manual online here: http://www.ducatimeccanica.com/marzocch ... /index.htm

The amount of oil depends on the travel of the forks; not all Morinis use the same quantity:http://www.ducatimeccanica.com/marzocch ... chi_25.htm
Morini stuff on RealClassic.co.uk: http://www.realclassic.co.uk/profiles.html#morini
bobajob
Posts: 106
Joined: 02 Mar 2013 18:34
Location: Christchurch, Dorset
Location: Christchurch, Dorset

Re: 10W or 15W fork oil

Post by bobajob »

Guys,

Thanks for all your comments. I'll start with a decent 15w and take it from there. The forks were firm but not unduly so and I'd like to get them working in a similar fashion again.
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