Modern Vespa

I have some gearbox oil leak at the rear hub nut.

But it doesn't leak into the brake drum but it got squeezed out at the hub nut.

There's no oil inside the brake drum so the seal is intact.

I've never seen like this.

Is the hub a tight fit (no rocking back and forward when tightened up)?

Must be leaking along the splines, if there's not excessive movement then perhaps you might clean and dry the splines completely, then use some silicone gasket stuff on the splines. Unlikely to make it difficult to remove I would think.

What rims are those? Never seen them before.

Along the idea of the splines, did you replace the axle and maybe the splines are so long it's inside past the bearing and seal?

Also, when you replace the bearing it's worthwhile fitting the type with covers like this. I usually take off the cover facing into the case so it's still lubricated by the gear oil. They're not a seal as such, but I think they do tend to hold back oil and let your actual seal work a bit better.

Thanks for the replies.


I gave the nut 80Nm when tightened it and fortunately didn't forget to insert the cotter pin.


I put some grease to the splines to prevent corrosion.


If I put some RTV on the splines will it be possible to remove the brake drum when I change the brake shoes?



The rims are from Indonesia, a Pinasco ripoff since European manufacturers notoriously neglect 8 inch VBC riders when it comes to tubeless solutions and disc brake upgrades. I use them with SIP tubeless tires and they work flawlessly. As for now it's the only rim that offers tubeless feature for 8 inch VBC wheels.



That's an "RS" bearing. I installed the "ZZ" version but the oil isn't leaking there.

Sip makes tubeless 8" rims, they're not split rims though.

It's for the VBA/VBB not for the VBC.

You get a much better bond with say, a carb box to the case with RTV but it still comes off easily. I think it should stop any leakage along the splines assuming there's no movement between hub and shaft. If there is then it won't last. Do you know if they are available anywhere outside of Indonesia? SubEtherBASS could really use them. Yes the VBC is seriously lacking in brake options! If the oil isn't leaking through the bearing, then it must be leaking around the bearing. Either outside (worn case) or inside (worn shaft). Neither of which sound like great options!

I will jack up the scoot in the next few days and check that brake drum. I assume the splines are a bit worn. If so, I'll put on a new brake drum and check.


The rims are sold in Indonesia. Mine are from there, too. They cost about a hundred bucks a pair excluding postage. They're available in matt black and chrome/polished.

Ohh my hell yeah!
He even has the correct (yellow) coloured hub!

Found them! I'm assuming they would not sell outside of Indo? Not sure how that works.

https://www.tokopedia.com/istanavespa/velg-pelek-tubles-r8-tubeless-gs-gscooter-modular-polish-cnc-ring-8-set-vespa-super-ps?aff_unique_id=&channel=others&chain_key=

$95aud... take my money!

Now, if only I knew an Aussie Bogun who is travelling that way to bring them back, as know freight is a killer!

I lifted up the scoot onto the jack stand and I could spin down the hub nut with a pair of needlenose pliers it was that loose.


Anyways I can't really see any damage to the splines. It just came loose bypassing the cotter pin somehow.



















And a clean closeup of the rim.

I have a socket with a long bar so I can stand on it to do it up super tight. And a wheel holder so it doesn't move while I'm doing it.

Hub looks fine, how about the axle?