Filling for go-cart tyres.

[killercarrot]

If you go to ATS (the industrial division) they can send them away to be filled with a rubbery compound to make them puncture proof.
I have a pair of kart rears treated in this way , BUT they are sooo heavy I cant use them, probably about 5 kg a piece now.
The cost was comparable to buying puncture proof tyres from technobots, I think they came out at about £25 a tyre (depending on tyre size... these are wide rears, narrower rears or fronts would be cheaper) plus a tube plus obviously VAT... didnt manage to wangle any freebies on that deal...
I dont think Ill be using them, so make me an offer... trouble is postage will probably make it not worth while.

[swedemac]

Thanks, but I got shudders from reading that weight . 5 kg a tyre is simply to much...even if they probably could take a direct hit from a bazooka .

[jeremy_cuss]

Markus,

I had rear go-kart tyres on my last robot, and found that I could run them with vitually no air pressure for a 100kg robot. So I never filled them with the foam that I had bought, and that certainly saved weight. I did make sure that the tyres were fairly well protected within the body of the robot. You may not need the foam. Check out your robot first. (Obviously you may need significant air pressure in the tyres to achieve your design surface clearance, but otherwise.....)

Jeremy

[swedemac]

Ok, thanks Jeremy. We will wait with the filling till we know how the robot acts with different tyrepressures.

BTW...any good advice on how to best separate the wheel from the hub? Its really tight and I dont want to ruin the only pair of tyres we have .

[jeremy_cuss]

Markus,

It wasnt a problem that I came across. Im not sure whether you are having trouble taking the tyre off the wheel hub, or the taking the wheel hub off the axle boss.

I used a split nylon wheel hub - very light and strong, and an aluminium axle boss that gripped the axle and was driven through a keyway. Everything fitted together and came apart easily.

For the new robot, using smaller wheels, I machined down the boss to fit, and drilled new holes in the split hub to fit the boss.

[flipperbot]

You can buy foam inserts for split rim hubs off the shelf at a good go-kart shop, they dont weigh to much either as they are ment for racing!

[petec]

We use plumbing insulation, but you really have to push hard to get it in tight enough to pack out the tyre. You can rivet the tyre to the wheel hub I guess....

Does anyone know any good online go-kart tyre suppliers? I tried looking yesterday and apart from 300 links to Tornados site, I only found one - very expensive.

[mightymouse]

Try http://www.faikartline.comwww.faikartline.com , I buy my nylon hubs from them and delivery is next day.

[richard_morris]

Why is it so important to fill kart tyres anyway? They are hardly ideal for robots - and the nice flat floors we have dont require the compliance of a pneumatic tyre.
We use the tread section of kart tyres, but cut off the sidewalls and bolt the treads straight onto our wheels - These cannot be punctured now! Better still, the fancy stuff Ed uses on his Storm 2 wheels.