Front inner tube leak

philrock · Post by **philrock** » Thu Nov 12, 2015 5:54 pm

I recently got my 1966 CB77 running. It had been non-operational for about 10 years. In fact it had been in about 200 pieces for about 10 years, and was that way when I bought it.

Because I am not the patient type, I did not change the tires at first. They were about the consistency of granite. The rear tire / tube held pressure o.k. The front tire / tube had a slow leak - about 0.5 psi per day.

I changed both tires and tubes. Again, o.k. on the rear, and a slow leak on the front.

I brought the front wheel assembly to the local motorcycle repair shop and had them replace the tube. Still a slow leak.

Any idea what's going on here?

I did notice when I began inflating the first new front tube that the valve stem did not seem to be seating easily inside the rim. I wondered if the tire beads are too close together to let the valve stem seat the way it should.

Any insights on this problem would be appreciated.

Phil

Hahnda · Post by **Hahnda** » Thu Nov 12, 2015 7:04 pm

Maybe you have a sharp spot inside the rim, possibly from a spoke? It keeps putting a tiny hole in your tubes.

The valve stems really don't seat into the rim. I don't think that is your problem. You could have a loose valve I guess. Could try tightening the valve core if you have a wrench or a cap that has the little tabs.

G-Man · Post by **G-Man** » Fri Nov 13, 2015 2:00 am

Phil

A bit elementary this one and I apologize if it's not very 'PC' but I always spit on my finger and rub that over the end of the valve. If there is a leak at the valve you will get a little bubble as the air leaks out .....

You could also wipe soapy water over the entire tire / rim to see if there are any bubbles.

G

Hahnda wrote:Maybe you have a sharp spot inside the rim, possibly from a spoke? It keeps putting a tiny hole in your tubes.

The valve stems really don't seat into the rim. I don't think that is your problem. You could have a loose valve I guess. Could try tightening the valve core if you have a wrench or a cap that has the little tabs.

LOUD MOUSE · Post by **LOUD MOUSE** » Fri Nov 13, 2015 8:01 am

I see you use the same Test Kit I do. .........:-). ....lm

G-Man wrote:Phil

A bit elementary this one and I apologize if it's not very 'PC' but I always spit on my finger and rub that over the end of the valve. If there is a leak at the valve you will get a little bubble as the air leaks out .....

You could also wipe soapy water over the entire tire / rim to see if there are any bubbles.

G

Hahnda wrote:Maybe you have a sharp spot inside the rim, possibly from a spoke? It keeps putting a tiny hole in your tubes.

The valve stems really don't seat into the rim. I don't think that is your problem. You could have a loose valve I guess. Could try tightening the valve core if you have a wrench or a cap that has the little tabs.

G-Man · Post by **G-Man** » Fri Nov 13, 2015 10:04 am

LM

Handed down from my Dad who could change a rear tire on a tractor without any special tools. :-)

G

LOUD MOUSE wrote:I see you use the same Test Kit I do. .........:-). ....lm

G-Man wrote:Phil

A bit elementary this one and I apologize if it's not very 'PC' but I always spit on my finger and rub that over the end of the valve. If there is a leak at the valve you will get a little bubble as the air leaks out .....

You could also wipe soapy water over the entire tire / rim to see if there are any bubbles.

G

Hahnda wrote:Maybe you have a sharp spot inside the rim, possibly from a spoke? It keeps putting a tiny hole in your tubes.

The valve stems really don't seat into the rim. I don't think that is your problem. You could have a loose valve I guess. Could try tightening the valve core if you have a wrench or a cap that has the little tabs.

philrock · Post by **philrock** » Fri Nov 13, 2015 10:39 am

Thanks for your replies.

It did occur to me that the valve core might be leaking. I removed it and put a little WD40 on the seals - it didn't help.

I should have tried the soapy water trick, but did not. It's now in the hands of the shop, who had the same thought as Hahnda - something sharp poking a hole in the tube. I'm hoping to hear back from them later today.

Phil

G-Man · Post by **G-Man** » Fri Nov 13, 2015 12:06 pm

Easy enough to test the tube in a bucket of water if it's out of the tire.

G

philrock wrote:Thanks for your replies.

It did occur to me that the valve core might be leaking. I removed it and put a little WD40 on the seals - it didn't help.

I should have tried the soapy water trick, but did not. It's now in the hands of the shop, who had the same thought as Hahnda - something sharp poking a hole in the tube. I'm hoping to hear back from them later today.

Phil