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Tubeless Rims

One of the many convenient designs to be found in vintage Vespas (up to and including the PX series and the T5) is the front-rear interchangeable split rim

Scoot RS have been the first to produce and sell tubeless rims ( http://scootrs.com/moreinfo.cfm?Product_ID=733 Scootering Magazine 2004

Scootrs_stainless_tubeless_10in.jpg

Scoot RS 10" x 2.1 Tubeless Rim: Steel

SIP manufacture to a CNC-milled aluminium tubeless rim (in different finishes) in 2 different sizes: 10" x 2.5 and 10" x 3.0. Both these rims cause misalignment to the left. The latter rim uses spacers and can be fitted with a significantly fatter tire (up to 130/70-10 or 120/90-10). The former rim, which would ordinarily be the "replacement" rim for the standard split rim, has considerably thicker walls than a stock split-rim wheel, and consequently it does not fit comfortably on the stock wheel bolts. Some riders who have used the 10" x 2.5 rims have removed the 5 bolts on their stock wheel hubs (not an easy task!) and replaced them with bolts 5mm longer. The same problem affects the fitment of the spare wheel to the spare wheel holder on the PX (around the battery). Again, because of the thickness of the walls, the plastic spare wheel holder bolt will not reach its hole, and consequently if a rider wishes to fit a spare wheel to his PX, he has to replace not only the bolt on the plastic spare wheel holder but also the two bolts to the left and right of the battery with bolts perhaps 5 mm longer.

SIP_Alum_rims_10in.jpg

SIP 10" x 2.5 Tubeless Rim: Aluminium

The SIP rims are supplied with 2 different types of lug nuts, an acorn-shaped nut and an hexagonal nut. The website recommends using the supplied spring washers and plain flat washers with the former and loctite only

lug_nuts.jpg

The heretical 12 mm lug nuts for the SIP aluminium rims

It should be observed that there are also floating around on the market identical rims to the SIP rims stamped FA Italia.

Handling Issues as a Result of Misalignment to the Left

Because the 10" x 2.5 rim shifts the centre of the tyre 0.4" (1 cm) to the left, there will be an adverse effect on handling. The issue (debated on forums) is whether this effect is negligible (as SIP contends). A second line of inquiry, if the handling is found to be significantly

The main handling issue concerns turning and, not as some would suppose, braking. The offset to the rear wheel causes steering in one direction to be easier, and in the opposite direction, to be difficult.

In general, while it is true that certain riders - perhaps more fastidious in their riding styles - have complained about the unusual and awkward handling caused by offset rims, it appears that most users do not regard the offset as causing significant adverse effects on handling.

For those concerned with the offset, there are two solutions. One is to offset by shims or other means the front wheel by an identical margin in order to re-align front and rear wheels. The second solution, obviously more challenging, is to shift the whole engine to the right. These solutions have been discussed on fora, but it is not clear whether anyone has actually ever carried out these modifications successfully.

Removal and Fitment

Experience has found that both the Scoot RS and the SIP tubeless rims are - compared to the ease with which the split rims are changed - difficult to remove and fit. The black finish on the SIP rims is easily damaged even when the greatest care is taken with them.

DSC_1488.JPG

SIP aluminium rim with black finish - front wheel of PX 200 E (disc brake)

Scooterists should note that, in the terms of safety, tyre rating is probably more important than tubeless rims, as many tyres are designed for low speeds (such as the J rated tyre pictured above - although note it is capable of a heavier load than other J rated tyres commonly found on Vespas) and low loads only - see the discussion in Tyres

More info?

  • Are any of these rims TUV approved (i.e. have they gone through the German safety standard)
  • Has anyone actually experienced a flat using one of these?
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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Paul McIntosh,
Mar 25, 2015, 2:00 AM
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