I notice that Norman Hossack has put one of his forks on a ducati 800. Lighter, stiffer and no dive under braking. Could be the way forward.
Oh cool, pictures or link please. I have always rated this type of front end and would love to ride one.
Norman Hossack's 800 ducati is at Norman Hossack Engineers a Trellis Front Suspension on a Trellis Frame Ducati 800
I had a long and detailed email dialogue with norman Hossack last year about his design and it's influence on John Britten. According to Norman, he was at a 'drink up' in a pub in west london in the mid 1980's - along with some Kiwi bike racers, apparently they sat around all afternoon talking about his fork/suspension etc. These racers went back to NZ and the idea filtered though to John Britten. It seems to me that the trellis framed ducati's would make ideal bikes to have this kind of fork.
BMW have used this on a 1200 I think, when this was put thru its paces on the track it killed the front tyre, sometimes dive is useful (changes the footprint). Hossack goes on and on about how BMW 'took' the design and never paid royalties but Hossack copied it from the Double Wishbone suspension. Itself, introduced in the 1930's.
Often wondered what happened to him. Back when i first saw Vernon Glashier on the race bike at Snetterton i imagined what a TT2 Pantah with a triangulated round tube version would be like. Carbon fibre would be a good way to go as well. Vernon told me that he could always run the softest available front tyre and they always looked pristine at the end of the race.
Dive can be usefull ? No actually. On a bike with conventional forks, applying the front brake causes the fork to compress which has the following effects : (1) Reduces the trail which makes the bike less stable. (2) Uses up some of the suspension travel so there is less available if you hit a bump. (3) Imparts a bending load on the fork which causes stiction. (4) Imparts huge loads on the headstock which is not ideally designed to resist the forces placed on it. None of this happens on the Hossack/Fior.
All of that is correct. Unfortunately modern front tyres are designed with all that in mind, so for race use at least the Hossack design is largely dead, unless you can persuade a tyre manufacturer to build you a tyre to suit.
Its racing application may not be dead. As mentioned, what if the lack of fork deflection allows a long engine to be mounted a few centimetres further forward ? This then allows an equal distance from the crank to both the front and rear wheel axles that is not otherwise possible with a 90 degree V twin.
One of the UK bike mags last year did a feature I think, on a guy who was involved in the Yam GTS1000 thing with a funny front end. I remember him saying Yamaha compromised his design on the production version; so in his words wasn't as good as he designed it. The article did explain the forces going through a conventional fork set up. Headstock, fork deflection etc. Some of the forces were very very high. His fork from a load path angle seemed far better. I think he's trying to get a bike company to back him. His fork looked good on a Gixer running test bed.
I remember that Yam going to the TT. I thought it was a bit brave because the thing weighed a ton cause it was really a kind of tourer. The designer was right tho, the forces are resisted (by braking) by a strut in line with them, as apposed to the nearly 90 degrees of a telescopic fork.
What is the difference between the load on the tyres? None. The acid test is how the forces are fed back into the bike.
Is Mr Hossack offering a Frame conversion kit or service for earlier Ducati's then ? I wonder why he picked the bike he did.
Frame of bike in keeping with tube design of fork perhaps. really liked the 'funny' front end on the Gixer in Fast Bikes (i think). Looked very clean from the side; easy to remove/clean front wheel as well.
