Hello all,after a long struggle, I managed to drain the fork oil from my scooter.
I have been looking into fork oils, and I need some advice, mainly whether I should go for synthetic or mineral.
Just to let you know that the reason for wanting to replace the fork oil was some stability problems I had even in slow speeds.
Also, I had a look at the steering damper, and I noticed that there is some oil coming in and out when I turn the handlebar. Is this normal? If not is it fixable or would I need to replace the damper?
Many many thanks,
Sol
Synthetic fork oil is more robust. As with synthetic engine oil, the molecule chains take much longer to breakdown and so the oil performs better and longer under stress and high temperature conditions.
Most makes of oil will be suitable for the task, I use Morris Lubricants currently but have used Rock Oil, Castrol etc in the past so don’t sweat it too much.
Use the weight of oil that is specified ie. 10W or 15W and fill to the correct level.
Forgot to answer the steering damper question. It sounds like the damper is leaking past the seal which is the beginning of the end. Gradually the oil will seep out as a light mist until the damper performance is compromised (or the technical term 'kin useless).
Thanks for the reply spannerman!
I will go for synthetic then, and probably Castrol as it is easier to find.
Good thing you mentioned the oil weight! Aprilia recommends 5w - 20w. To be honest I have no clue what each feels like, so I think I will go for 15W which is middle - to - heavier.
Regarding the steering damper, is it something I can or can be fixed, or should I replace it now that the whole front is exposed?
Cheers,
Sol
id go 10w in scooter forks 
did you measure what you got out?
steering damper may be serviceable but it may be cheaper looking for one on ebay!
Yep, I got 250ml from each side which is the amount specified in the manual.
Could you please elaborate on the oil weight? Why would you go for 10W? Im just clueless about this…!
Cheers,
Sol
Oil “weight” is a measure of its viscosity. i.e. how thick is is, usualy measured at a set temperature. (It gets thinner when hot.) The lower the number, the thinner the oil and, surprise, the reverse.
Some oils are sold with two weights, e.g. 5W-15. This (sort of) illustrates the weight over its manufacturers prescribed operating temperature range. 5 when it’s hot (thin) and 15 when its cold (thick).
Other stuff is sold as “viscostatic” meaning it doesn’t change weight within a given temperature range. (It does a bit, but let’s not go there!)
Oil weights in suspension are fairly important in that they have a remarkable effect on the damping in one or both directions. Too thick and the suspension can firm up and/or be very slow on rebound to return to the proper position, too thin and you can have a pogo stick instead of damping.
Bike manufacturer usualy get it about right for the country the bike is being sold in to.
If you want to play games and experiment do so by all means, but do it in small steps.
Used some cheap iffy stuff in the front of a big heavy bike once, turned out to be far too thin, and the handling became quite interesting.
Scooters have steering dampers?:w00t:
Yep, its an Aprilia Atlantic 500, which comes with a steering damper!
