Why don't we use solid rubber tyres on our sulkies?

[Messenger]

Krafty Bart at Maryborough today, yet another retired from a race due to his tyre being contacted.
I know I have asked the solid tyre question before but I still don't get it. It is definitely happening on a weekly basis lately

[Showgrounds]

Same reason we no longer use them on cars. No tread, no grip, no comfort and because sulkies don't have any form of shock absorbsion it would eventually rattle to bits.

[Messenger]

But they do use them on F1 cars. Slicks have more grip than treaded tyres except for when there is surface water. I imagine sulky tyres are pumped to the same pressure that racing cyclists would use - so no shock absorption there

[Showgrounds]

Formula One tyres are slick because they race on bitumen. Watch what happens whenever they stay from the racing line hit loose rubber "pebbles" on the side of the track - no grip! They usually run about 14-16 psi pressure. Sulky wheels are pumped tight to lessen friction when tracking through sand bases. On grass, you use less pressure in the tyres to reduce the bounce.

The 1979 Tasmanian Pacing Championship was run on the steeple grass at Slick as the new track was being built for the nearby Showgrounds trots. The late Kevin "Boofa" Innes had Chairman Joe and Lea Sands racing. Boof was an old cyclist and was not willing to listen to the advice of locals. Instead of letting some pressure out of his tyres he pumped them tight as a drum!

He used a "Yank" style Tasman sulky similar in design to those commonly used today with the seat mounted atop the cross bar between the wheels. This design, the high tyre pressure, the extremely rough steeple grass surface and Boof's not inconsiderable weight conspired to undermine the sulky's structural integrity. It started to give way coming off the back straight and when Boof returned to scale there was a number of structural cracks and a bow in the cross member tube under the seat. It was cactus.

That said, the race tyres used today appear so much better in quality than years ago.

[Messenger]

No doubt you should have less pressure on bumpy surfaces
My cycling experience (mountain and road) tells me that it is tyre width that makes a difference not tread (except on wet bitumen) on rough surfaces.
An F1 straying off the track is still going troppo tread or no tread. Solid tyres can of course have tread if you really want them to, an example would be wheelchairs (people that are wheelchair bound dont want punctures although many belong to the RACV for emergencies)
Do you mean 114 -116psi ? That is what a racing cyclist would use. Or is 14-16 a Nitrogen filled F1 tyre? I think they are low 20's (less than our passenger cars because F1 cars are much lighter)

[Showgrounds]

Depends on rubber compounds and tracks. Pirelli recommended 27psi on fronts and 22 at the rear for Imola in August, which is about 3psi less than what is considered normal. Treaded tyres used in the wet use lower pressure again which, along with tread wear, leads to fast degradation on drying surfaces. Not a problem at the trots, though.