Fork oil for Aprilia Climber

[nick5446]

I've got this Aprilia Climber 280 trials bike. There is virtually no information about these things online. I just rebuilt the forks, but have absolutely no idea how much oil to put in them. I've read all the forums and can't find anything. Supposedly manuals are few and far between, and those that exist are in Italian. I did find that most people recommend 5-7.5W oil, so there's that.

Anybody have any guesses as to how much oil I should put in these things? I don't need perfection, and I won't be trying to win any world titles with it. I had thought about just looking up what a KX80-ish bike takes, since the forks are a similar size, figuring it could get me close. Me hesitation with that is that the left and right fork have different internals, so it stands to reason that they might take different volumes of oil. Any ideas?

[Paul_E_D]

All forks are the same in principle. They need enough oil not to cavitate, or suck air into the valving. To do this you fill slowly and pump the air out. You can feel when there is enough to stop sucking in air. Then you continue filling to reduce the air gap. Air is more compressible than oil. More air offers a softer ride. Less air, firmer. Start with a 100mm air gap and tune it to your liking.

[nick5446]

Awesome, thank you!

[number9]

I'd love to see pics of this thing...

[tls25rs]

I'd love to see pics of this thing...

aprilia climber 280 - Google Search

[Paul_E_D]

Cool! Which snazzy color combo is yours Nick?

[typeone]

+1 for pics ... i'd love to grab a random vintage(ish) trials for chasing the kids around the yard. we started setting up little 'logs' at the end of the season for Oset practice.

[nick5446]

Attachment 48610

Green Goblin!

[typeone]

damn, that's sweet! needs purple grips 'n MaxiPad

[Paul_E_D]

LOL, THat's actually the best color I've seen!

[nick5446]

Price was right...can't lose!

[Garandman]

Nice sign.

[aldend123]

Me hesitation with that is that the left and right fork have different internals, so it stands to reason that they might take different volumes of oil. Any ideas?

I think that's partly why the trend seems to be going off oil height instead of volume. The other is that seems impossible to truly get all the oil out.

If you haven't done the job already, assuming you're using one of those turkey baster tools, fill to what you think would be the highest you'd want to go. Then set the tool for the lowest level you'd want to try, and remove the oil required. Note how much oil was removed from each leg. Now you can play with the lowest level, and add oil as you want while still knowing if you're under the assumed highest level.

I don't think I knew they made trials bikes. Neat. Kinda jealous, though I won't want to be you trying to track down some specialty parts

[nick5446]

Yeah, so far specialty parts have been tricky...most are coming from EU/UK. Fortunately I haven't needed much. I going to fabricate a rear brake pedal clevis and an air filter, then I should be good to go.