Post by Iconic944ss on Nov 18, 2021 15:51:35 GMT
Ducati SS / ST forks
Here is some relevant information about them.
Having checked all the possibilities between Ducati forks over the years.
Fork lengths from top of fork to axle centre.
ST2/4. 696mm
ST3. 726(and later ST4s)
748. 716(and749/916/996/998/999)
Ohlins. 716
Fork stanchons Diameters
ST All. 50/54mm
748. 53/53(and749/916/996/998/999)
Ohlins 53/56
If you look at the first photo from the top in order:
Ohlins 749s
ST3s(and later ST4s)
ST3
ST2/4(these are ST4s)
Photo 2 shows the fork adjusters
The original ST2 forks had compression and rebound damping.Ths screw in the centre of the fork top is rebound and there is a similar screw inside the fork bottoms for compression.
When the ST4 was introduced the forks only had compression damping but fixed rebound with no adjustment, must have been a cost cutting decision,the ST2 was the same.When the ST4s was introduced forks had rebound damping back and gold TIN coating to reduce friction.ST3 had same forks as ST2/4 no rebound and ST3s same as ST4s.
ST3 and later ST4s forks are 30 mm longer to allow for new stepped top yoke and handle bar mountings.
It's possible to fit 748/749 forks to the ST using the 53/53 yokes.On early ST 20 mm difference and on ST3 it's 10 mm.
Fitting Ohlins is a much bigger job as the steering stops are different and need to cut off the originals and reposition due to much bigger bottom yoke.
I fitted a set of Ohlins forks and yokes to a project ST a few years ago and machined out the handle bar mountings from 50mm to 53mm to fit the forks.
Other forks possible to use are 848 which are also 53/53 and similar length to 749 but have different axles and radial brake mounts so the you have added expense of brake calipers and wheels.
Hope this helps - Alex.