Modern Vespa

I bought some beautiful black Pinasco Tubless Aluminium rims a year ago and fitted some nice Heidenau race/road tyres.
I see that when I fit them to the drum there is only 5mm left over for the thread to hold the rim on the hub?
When I measure a standard rim, the threads on the drum for mounting have 10mm left over. With the pinasco rims when on the drum there is only 5mm thread left to add a washer and nut.
I cant even get a nylock nut on to secure it.
Obviously Im not riding it with the rims until I can find a solution.
Anyone else have the same issues?
Any solution?
I guess I could fit longer studs on the drums but Im not sure if thats possible as the look like the studs are secured to the drum at the back of the thread…

Cheers Robbie

I always replace the studs with 8x35mm button head allen bolts. It's the same for SIP rims, studs aren't long enough. If your studs are pinched from the other side and not cast inside the aluminum, you can replace them. I use double nuts, turn the studs clockwise a bit more so the backside extends, grind the pinched side and then unscrew them normally…

That's exactly what I did to mine also, I did it with stock rims to be able to get nylock nuts with built in flange I use.

I measured the thickness of standard split rims, pinasco split rims, and SIP rims a while back.

Off the top of my head...
Stock split rims -- 6mm
Pinasco -- 8mm
SIP -- 6mm

I like the Pinasco's, but there are definitely things about them that could be improved.

Thanks guys for the feedback and advice….