Service guide for my son's Manitou Splice says that the required fork oil is 5/40wt. Is this the same as 5wt or something altogether special?
It's a measure of the oil's viscosity at two different temperatures, I thought for engine usage- the first number represents the 'thinness' of the oil when cold, the second when it heats up to the engines operating temp.
To be honest I've never thought there was a need for multiweight oils in mtb forks- I don't think the oil heats up enough, but may be wrong. Certainly when I used to race mx we used straight weight oil in the forks (that was in the seventies and eighties though, so things may have changed)
its basic motor oil for a car. its for the semi bath lubrication. go to halfrauds and look at the engine oils they will all have similar numbers on them. but the cheapest natural oil for your forks.
cheap oil and cheap grease make the forks work better! i tried posh stuff in my shermans and they worked good for 2 rides and then siezed up.
put the cheap stuff in and they were buttery smooth.
Thanks for the help.