900ss cylinder stud failure

Dear all 900ss owners,

I’m carrying out an engineering structural analysis for my degree thesis on the Ducati 900ss cylinder stud failures. I’m aware that the stainless steel studs fail between 90-96 models (roughly) and they require a HTS replacement.

I’m trying to identify/locate a couple things these are,

Anyone that has photographs of broken stainless steel cylinder head studs, or even better still, has some old studs and can possibly post them to me.(i will pay postage)

The location at which the studs failed, ( i,e threaded region or shank) and if the stud had undergone corrosion in the location of the failure and which cylinder it was located.

Anyone that can identify to me the mileage that their 900ss cylinder studs failed at and the year of their bike.

Many Thanks

Dominic

Hi Dominic,
I remember that fault only too well, I was working for one of the 3 Ducati importers in the UK at the time, and had to cope with the ensuing correspondence and work.
I’ll see if I can contact anyone who may be able to send any info to you.
Good luck!

That would be great, I’ve been to my local Ducati dealer and phoned a couple of local classic bike restorers who deal with Ducati, they all gave me the same response.
Yes, they break but we throw them in the bin once replaced. which is what I was expecting!

Thanks any help would be much appreciated.

Excellent, that would be great. Thank you

I’m interested to know if they fail during riding or during maintenance?
I’m thinking a possible failure mode is that the nuts corrode onto the studs and then shear overload/brittle failure occur when removing for maintenance, this being more liable on the front cylinder due to being in the dirty region behind the front wheel.

Or if they fail when riding due to a fatigue crack growing at the threaded notch possibly most likely to occur during riding.

I have read mixed answers for failure on many (very old) forum posts of failure during maintenance and during riding!

One of my friends has written “My Monster,1995 suffered a broken head stud,it snapped halfway up and was easy to remove…all eight were then replaced by studs purchased from Baines Racing and 30000 miles further on,there have been no problems.
I recall at Sports, when the problem arose, we assumed that the front cylinder was the one likely to suffer since it was prone to bid temperature changes…ie splashes from big puddles and soakings from heavy rain…but it soon became apparent that the rear failed too.
I remember well the occasion where Steve replaced the front studs on a 900ss,the bike was on the bench and he ran it just to check his handiwork when there was a sharp PING…one of the rear studs had snapped!
Geoff Baines may just have some old studs…he was one of the first to stock replacements…”
Hope that’s of some help?