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Can anyone give me abit of advise regarding tyre valves on cast wheels.

My old tyres when removed had tubes fitted front and back, I was told this is illegal? or certainly frowned upon.

My question is where can I get the correct size valves. I really want the modern metal 90 degree angled type. The holes in the wheels measure 10mm (front) and 8.7mm (rear). I've found 8.3mm valves which I presume are correct for the rear, but I cant find anything suitable for the front. They seem to jump from 8.3mm to 11.3?

Some cast wheels are designed for tubes especially from the late 70's early 80's. Several bikes I have owned are like this Yam LC350, Moto Guzzi V50, and almost certainly all cast wheeled morinis. It is not illegal to put a tube in a tyre on a proper tubeless rim.

Russell

My BMW with "snowflake" mags require a tube as well...
find a better tire shop.

Hi
The Morini grimeca cast wheels are not designed to use tubeless tyres ie any tyre without a tube,if it's a case of finding a right angled valve then angled adapters are available cheaply on e-bay,I recently bought a pair for a very reasonable £4.20 including free P&P.
Hope this helps.
Dave.

Hi again
The adapters I bought on e-bay are item number 350412426876,I use them only when I need to add air to the tyres,not keeping them on as they may cause the wheel(s)
to become out of balance at higher speeds?

Dave.

Thanks for all the replys.... Short of a VFR400 this is the only bike I've got/had with cast wheels! Bought tubes so will drop the wheels off at a local tyre place rather than my local bike shop. Would put them on myself but I dont trust myself marking the shiney wheels!!

Whilst all the above about cast wheels being either designed for tubeless or not is true I have found that a lot of cast Italian rims of that era seem to cope tubeless as long as the valve aperture is reemed to suit a tubeless valve stem.

There is hot debate on some forums as to if you should or shouldn't. I really don't care but found that after buying a couple of second hand Italian bikes I had been running on tubeless without even realising it. The issue is that the rim doesn't have the safety bead that tubeless tyres should have. I only realised after getting a puncture. At no stage did the tyre ever come away from the rim and a bead breaker was always needed.

The advantages of tubed tyres is that they don't tend to blow out but go flat slowly. A small plug kit and inflation device can get you going without too much hassle.

Up to you.

Cheers

Rod

Putting a tube into a tubeless tyre generates more heat, so the speed/load rating is reduced. Many tyre manufacturers have information on how much reduction is recommended. With Roadrunners being rated to 130mph a bit of de-rating is not really a problem.

Running tyres tubeless on rims not designed for it is not a good idea. Your insurance would be invalidated and you'd leave yourself open to prosecution if the state of your tyres was in any way implicated in a crash. It's possible, but the safety bead was introduced for good reason. There are rim converters available, essentially a very low profile tyre that fits into the well and keeps the beads seated. They're generally used to convert spoked wheels.