Modern Vespa

Was dropped off this wheel set- SIP Tubeless 8" rims with tires mounted for a project. I mounted them today and I do NOT have any confidence in them. They are so thick the axle does not index into the rim and the nut are only 1/2 threaded. The drum is not standard, but SIP CNC.

What is your experience?

Mine sit like the Pinasco picture. Hub bolts sit flush with the nuts when tightened to spec.

I can take a pic in the morning.

Is the issue with the thickness of the rim itself, or that the SIP rim doesn't fit onto the hub because of interference with the raised center section of the hub?

Seems like that latter, right?

no interference of the axle. in fact, the axle is not even indexed into the rim....which is what you want. I can weld on long studs on the axle. ....but that would be the only thing holding the rim to the axle. if the issue was interference, i would have removed some material from the rim and this thread would have never happened. please see photos.

Right. That's what I thought the photos were showing, but wanted to make sure.

One part is wrong, just gotta measure and determine which, it seems.

How does the thickness of the rim affect the hole's indexing on the axle ?

I felt like I did a pretty good job documenting in the photos. No? I can get some
Photos of the backside of a stock rim and the SIP tubeless later today.

In this case, it doesn't. This is about the center indexing/support ring of the hub being too large for the rim (or vice versa).

It's my fault for bringing up Pinasco's 10" wheels, which need longer hub studs if you're going to run them.

I was thinking (but clearly not communicating) that Pinasco doesn't have a great track record for measuring this stuff.

In the case, it's a SIP rim.. ..probably made in the same factory as the Pinasco.

I'm sorry. So this is just another case of a product being produced without checking to see if it fits and forcing the consumer to modify it to work ? I am so tired of this sh*t.

i think so too. i have sent the photos with description to my Dealer account with SIP. we will see what SIP has to say.

I will look forward to their excuse.

Can you take the hub off and get some pictures of the hub and rim bolted together from the back.

Spitball -
Is it possible they used the wrong axle?

Weren't the stud lengths different on some iterations? Maybe it is just M8 vs M10 and the length is the same? I don't recall. But just a thought.

Ignore that.. ^^^

I just looked and according to SIP studs are 16mm on both iterations of the 8" front axle.

Yeah. The issue is that the indexing ring on the wheel and the axle don't match.

Gick, what are the diameters of the hole and the ring?

Think I figured it out by looking at the backside of the rim.

Axle measures 52mm. Same size as the larger of the two internal diameters. The smaller one measures at 44mm. Why SIP did this really makes you wonder as it's a total optical illusion from the outside and really doesn't look good on a detail level.

Is it deep enough for the hub and just looks funny, then? Or does it cause the rim to sit with a gap between it and the axle/hub?

Here is my solution-

TIG weld m8 x 21.5mm lugs to the axle. Now I have lug threads throwing outside of the nuts.

Well sorted Gick!

Reminds me of Harley during the Shovelhead Days. Quality was horrible enough that is was said "HD builds the bike, you do the final enginnering."

Send them a bill for work done.

A+ on the perfectly positioned SIP valve stem cap for the picture!

That's how you know it's a Grade A+ Repair

A friend has a sidecar with same style rims.
He had one break & welded... from memory there were 2 different thicknesses available, this could be the thicker option

i am unaware of two different sizes and upon looking, cannot find anything different. Please point that out to me-

Hello to all,

Martin from SIP here. I thought I'd drop a note here regarding those rims. We actually point out that longer studs are necessary when mounting that rim. I'll enclose a screenshot from our webshop where this info can be seen. Same info should also come with our manual, longer studs are being listed in the "Recommendations" list for this rim. We know sometimes our shop has almost like "too much information" in it, but for the time being we feel that is the best we can do to properly inform potential buyers.

Hope this clarifies the issue at hand.

Cheers,


Martin