I was advised to get 7.5wt fork oil on a xc bike but it’s proving difficult to get hold of, at an agreeable price.
What differences will I notice between 7.5wt and 10wt?

2.5

ha ha HA HA HA HAHAHAHAHAHA!

seriously…a bit more damping.

See if your local motorbike placey has some. Comes in larger quantities at cheaper prices than if buying bike specific even though it’s the same stuff.

Try a ‘motor bike shop’.
Not all makes have equal viscosities.
If all else fails dilute down with 2.5wt – ‘need to do a bit of maths to get the ratios – too much red wine to try tonote.

mix the weights to get the right amount of 7.5
I do this with 15 and 5

Before you go any further, not all 7.5W oil (or 10W) is equal.

There are VERY loose criterion on what makes up oil weight.

If you go for a decent quality fork oil like Silkolene Pro RSF (probably the best) or Rock Oil or the like, you’ll probably only want 5W oil as that’ll be as thick and consistent as the cheap crap 7.5W that came in your forks from the factory.

10W will make them spike BADLY going over bumps, it’ll feel horrible, unless you’re about 18 stone in which case use thicker oil.

ha ha HA HA HA HAHAHAHAHAHA!

Back to the carbon techhead.

Try a ‘motor bike shop’.

That’s what I’ve tried and they all seem to have 10w, I guess they’re a biffers around here or crap riders like cynic-al.
Cheers for the info mboy.

Sorry, have I hurt your feelings?

can’t see why else you’d call me a crap rider.

Happy to race ANY DAY.

EDIT I can’t believe you got hissy over the above, have a word!

More info for you…

http://mahonkin.com/~milktree/motorcycle/fork-oil.html

It’s the “centistokes” you’re interested in.

You’ll see that a good quality 10W can be more than twice the thickness of a cheap 7.5W, and even some 5W will be thicker than cheap 7.5W stuff.

FWIW, Silkolene Pro RSF is widely known to be the best Fork Oil, so it’s worth checking it out. You won’t want anything heavier than 5W oil though. You might even want to mix 2.5W with 5W to get a desired rate!

Sorry, have I hurt your feelings?

I wouldn’t big yourself up too much -al.

EDIT I can’t believe you got hissy over the above, have a word!

😆 Hissy? I don’t do hissy. Happy to race ANY DAY.
How old are you -al?
Cheers mboy, I’ll have to get down to a decent motorbike shop or oil provider.
EDIT: Can I put you on the list of yappy little lap dogs that follow me around -al? It’s quite an exclusive group of leg humping little lap dogs, feel free to join.

This stuff is pretty good… It’s what TFTuned always used to use.

http://www.chainreactioncycles.com/Models.aspx?ModelID=8399

Silkolene Pro RSF easily available on ebay anyway…

http://www.ebay.co.uk/sch/i.html?_sacat=0&_nkw=silkolene%20pro%20rsf&_sop=1

CRC have 7.5wt rock oil in stock – £5.99. Sounds pretty agreeable to me!

http://www.chainreactioncycles.com/Models.aspx?ModelID=8399

i used the rock oil 7.5wt oil in my 888 bombers. worked a treat

I use Silkolene 5, 10 & 15 then mix it when something between is required.
Buy it all from my local friendly motorbike shop, loads cheaper than anywhere else, always on the shelf & top quality stuff.

Looks like the hungry troll wants feeding again.

10 points for guessing the reference 😀

If you are a complete monkey you can put motor oil in forks; as argued by some loon a few weeks ago.

What’s the worst that can happen?

Rock Oil is good gear; it’s not expensive, treat them well.