[Top Down]

... can anyone identify these tyres please? Came to me on three secondhand Caterhams and they annihalate those I already have on standard tyres.

They are wider, shinier, slightly bigger diameter and as fitted are slightly domed but even so their grip is far superior and the cars run much more quietly too.    

I'd love to get some more if I can.

Thanks for looking.

                        

[Kevan]

Can you post a close-up of the inside edge of the tyres, there may be a molded logo or tell-tale signs of being cast

[Top Down]

   

This is the inside wall. They are cast, no logos. Extremely stretchy and flexible. Super grippy. Not rubber.

[M.Soames]

Possibly urethane of a unknown shore rating ?.

I'll take a stab that they're "wasp" tyres, aka Wayne Allen Slot Products.

As you say they are really sticky they may also be Silicone , careful if they are ,as they will lift any grip your track has built up .

[Graham]

I am wondering if they are the Mustang Thunderslot tyres ? Alternatively Silicone or soft Urethane tyres perhaps.

[Top Down]

Not Thunderslot. The latter. Cast silicone or urethane but of the two I'd go for silicone as urethane gives off a white powder when you true them. These can't be turned down full stop. 

They're so flexible you can roll/peel them off the rims with ease and they spring back to shape.

I'm really after the source so I can get some more.

[Gordon Steadman]

If they are silicone, you won't be able to use anything else! Disastrous for urethane. I tried them once on my track and had to clean it all off. Terrible experience at Bordeaux as well. First heat won easily, second heat following a car with silicones on I had no grip and was nowhere.

Avoid like the plague.

[Kevan]

'these can't be turned down full stop' says silicones.

[GT40Racer]

They may be silicone but look a bit rough on the backside to me. Put a drop of superglue on the backside edge and try and stick something to it or take a sharpie and try and write on the tyre or a bit of paint if anything sticks then they aren't silicone those things will flow off silicone.

[Kevan]

They look like they could possibly be 3D printed.

...of course there's only one way to find out, ask the person you bought them from