Tubeless rims

[coaster]

That's a very well reasoned response from AF.

[coaster]

...............However, what I do know is that the ‘science’ of removable wheels that fit a hub is not unique to Lambretta or even V*spa. I can’t think of a car that doesn’t centre its wheels on the hub to take the load because those automotive engineers are well aware of the loads, particularly shock loads that can cause ‘slippage’ (as they say @ Land Rover) That’s why even ‘amateur’ car owners that adapt wheels of one marque to another use special centering rings to take the load through to the hub in the case of oversize wheel bores...

I can't think of any where the wheel centre is a tight fit on the boss on the hub IF there is always a boss? Car wheels have a dished (sometimes raised) seat for the wheel nut to 'centre' the wheel. That and the Clamping Force imposed on the wheel rim against the hub will be what stops any movement. Some wheel nuts have straight shanks that serve the same purpose

[Warkton Tornado No.1]

...............However, what I do know is that the ‘science’ of removable wheels that fit a hub is not unique to Lambretta or even V*spa. I can’t think of a car that doesn’t centre its wheels on the hub to take the load because those automotive engineers are well aware of the loads, particularly shock loads that can cause ‘slippage’ (as they say @ Land Rover) That’s why even ‘amateur’ car owners that adapt wheels of one marque to another use special centering rings to take the load through to the hub in the case of oversize wheel bores...

I can't think of any where the wheel centre is a tight fit on the boss on the hub IF there is always a boss? Car wheels have a dished (sometimes raised) seat for the wheel nut to 'centre' the wheel. That and the Clamping Force imposed on the wheel rim against the hub will be what stops any movement. Some wheel nuts have straight shanks that serve the same purpose

Having read the response from AF, it is clear that they consider that the fact that SIL may have supplied rims that no longer ‘touched’ the hub means that they can also do that with their own tubeless rims.

If SIL have done so, I believe that to be a departure from the original Innocenti design.

Regardless of the strength of steel in comparison to alloy, undoubtedly, some kind of ‘fit’ is preferable when it comes to automotive wheel rims & their hubs which should be ‘centering’

Anybody that has any doubt on this should be aware that, for instance, car wheels that are manufactured as ‘multi-fit’ with an oversize centre hole will be used in conjunction with centralising rings to allow adaption to a variation of vehicles.

These rings are preferably made of good grade steel but often made of alloy or even plastic, not that I personally condone the latter two materials.

The point is that a typical car centre ‘hub’ might be anything from about Ø50 to 100mm so you might understand why I’d prefer a ‘hard’ centralising ring if I were to use such wheels.

By comparison, the Lambretta alloy hub has a huge Ø220(?) mm centralising annulus (or spigot) machined specifically to perform a function that some would have us believe is no longer necessary.

If ever the old adage of “If it ain’t broke, don’t fix it” were more appropriate in the World of Lambretta, I don’t know where!

EDIT: As an afterthought, I have contacted SIP & will Post any response that may make on this issue.

[Fast n Furious]

That's a very well reasoned response from AF.

Spot on.

[Warkton Tornado No.1]

You won't get any disagreement from me on this Warkton. I'd much prefer the wheel to be centralised and locate on the hub than just to be held by the four studs.

Spot on.