I have recently aquired a front wheel and cannot identify it apart from the markings.

It is light so seems to be magnesium but has a notch for a speedo and takes an F1 type rotor.

Would the living museum collective give its opinion?

It's indeed a Speedline, probably from a early 500 SD , hence the sixbolt disc.
I haven't heard of any failing on the Parallel twins but on the heavier Beveltwins (other casting for 4 bolts) there have been a number of sudden collapsing, even when fitting a new tire and exceeding standard pressure to get it on the rim.
So let someone have a CLOSE look on them .
I had (a cracked) one on the wall to hold a garden hose and I saw it deteriorating from year to year.

ciao
ducadini

The 1979 Darmah had 4 bolt Speedlines while the 900 Super Sport had six bolt Speedlines. 1979 Mike Hailwood Replicas were also fitted with Speedlines (6 bolt) or Campagnolos (6 bolt).

Speedline wheels were the subject of a Recall in Australia due to them failing with cracks.

Magnesium wheels require to ALWAYS be chemically 'sealed' (see link below) to protect them from oxygen which can "soak" into wheel and corrode it from the inside out.

https://www.facebook.com/photo.php?fbid ... =3&theater

As I sit here wasting the day waiting for Mr. UPS to show up, I did a search on magnesium coatings. The gold like finish is called Dow#7. It's a dichromate chemical dip conversion coating. The green is Dow#17 and is an anodized coating. There is also a brown to black finish, Dow#9, that is a galvanic anodize. Although these coatings offer corrosion resistance (sealing), they are also meant to be used as a base for painting.

Me, I'd leave the old slick on it and hang it the garage wall. It's very pretty just as you show it, but with their bad reputation, I couldn't trust it.
Bill

I agree ; take no chances .

think I just worked it out, ironically it is the same type of wheel from a bike I used to own....

just had the paint removed kinda threw me..

1981 Mototrans Ducati Vento 350

have a look at the pics Phil shot in my garage before I sold it..

http://www.philaphoto.com/imageLibrary/ ... album=1467

anyway, so its not a mag, just light but i think I will still check it before I use it.

I'm not so sure it ISN'T magnesium.
First : Mototrans used the Speedlines only for a limited time, and later changed to the (parallel and Guzzi type) FPS aluminium wheels (just as Ducati did on the 500 SD twin) and those FPS are much heavier.
Second : the part that is bolted on the rear wheel to accomodate the rear sprocket carrier is nearly the same weight as the Campagnolo (which IS magnesium) part and a lot lighter than an aluminium one.
If it wasn't for the cast-in marking C for Campagnolo and S for Speedline, it would be difficult to see the difference (but there ARE differences between them)

I remember seeing some ads for elektron Speedline wheels in old Motosprint and Motociclismo magazines not so sure about aluminium sets .

Mine stays on the wall and the other set is just for mounting in bikes to move them around .

ciao
ducadini

They are magnesium.

Magnesium wheels are easy to recognise when the paint is stripped from them as they tarnish (turn black) very quickly as they oxidise/corrode.

This pattern of Speedline wheel is well documented as being made of magnesium for Ducati - Darmah, Super Sport and Mike Hailwood Replica in 4 and 6 bolt arrangements from 1977 to 1979.

It would be interesting to learn that the same pattern wheel when fitted to the Vento was aluminium. I shall post this question on the Ducati Singles FB page and find out if this is possible.

Stay tuned.

Those Vento wheels have 5 bolt discs so the casting must've been different.

ciao
ducadini