Non Vincent - cast wheels.

Hugo Myatt

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VOC Member
Sorry this not Vin related but I just want to tap into accumulated Biker knowledge. I have a Honda Nighthawk with cast alloy wheels The rear tyre goes flat in about five hours. No puncture. New valve. New tyre, been to the bike tyre place several times. They fitted it with black tyre gunge each time. No success. Driving me nuts.
Is the wheel porous? Is so any cures? Any experience of this? Grateful for any advice.

Hugo
 

Bod500

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Non-VOC Member
Put a tube in the tyre, if it does not go flat then it looks like the rim is porous. I had the same problem with a Suzuki jeep.
 

timetraveller

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Sidmadrid's advice is good. However, if you do find a leak via the water tank test you do not necessarily have to fit a tube. There are products, 'Greenslime' and 'Purpleslime' ( I kid you not) which go inside the tyre and seal it against leaks, punctures etc. I have used the greenslime product on a ride on lawn mower which continually got punctures from thorns and it is also suitable for pedal cycles. These are low speed applications and it has completely solved the problem. I understand that the purpleslime is suitable for high speed use but have no personal experience. There might also be other products.
 

Hugo Myatt

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Thanks everyone. I have been advised aginst putting a tube in it as a solution because of abrasion or tube creep.

Hugo
 

ET43

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Hugo,
Have you looked at the state of the rim where the tyre fits in the well. If this is at all corroded, air will slowly leak out. Bung a tube in it. Cheers, ET43
 

sidmadrid

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ET43,
Thats where the leak was on my Ducatti, cleaned up the inside of the rim with wet and dry, etch primed and paint, cured it. Just cleaning off the corrosion does not work, starts to leak in a week.
Tube is a quick fix whatever the problem is., sid
 

John Appleton

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Thanks everyone. I have been advised aginst putting a tube in it as a solution because of abrasion or tube creep.

Quite right Hugo. Fitting a tube in a tubeless tyre is only ever a "get you home " solution. The heat build up due to friction between tyre and tube is amazing. We have had this problem recently on a customers' BMW car. It would even go several days without loss of pressure, and suddenly one morning it would be flat. After several tyre shop visits it found its way to us. The reason for intermittant pressure loss was a hairline crack at the flange of the wheel, and this was being covered and uncovered by minute movement of tyre on rim.
John
 

Tnecniv Edipar

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Non-VOC Member
Also had this problem on the rear Mag (actually magnesium) rear wheel of my Ducati 851 Kit homologation. Ducati weren't too helpful , stating that it was a race bike so what did I expect !! Had it pore sealed by a foundry , end of problem !
 
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