Griso; front tire loosing several PSI per day. But unable to find leak.

[ett]

Hey guys,

Need some hints.

The front tire of my Griso keeps loosing several PSI per day.
It appears to coincide with installing a new set of tires about 4 weeks ago.

I've inspected the tire for any punctures. None found.
I've verified the tire valve stem is tightened properly.
I've replaced the tire valve with a new one. Both old and new valves are Moto Guzzi 90 degree metal valve.
I've removed the tire and inspected it's bead for flaws. None found.
I've remounted the tire to verify it's bead is seating properly.
I've checked the rim to see if it's bent. No bends found.
I've sprayed the entire tire; beads, tread, and valve; with water. No leaking air bubbles found.

What am I missing ?
Where else could the air be leaking ?

Thanks;

--ET

Found it ! See post #9.

 

[Woodaddict]

if you can take off, immerse in a tub of water. or place a big tub just under tire fill with water rotate till bubbles found, front or back. may have to prop or place weight on either side with center stand

 

[junglejim]

What Woodaddict said. I've had trouble finding leaks with my usual spray bottle filled with soapy water. They will show up if submersed.

 

[seagrass]

And increase the tyre pressure to about 60 PSI before submerging, you will be surprised how much easier it is to find a slow leak when the tyre has more pressure in it.

Seagrass

 

[ARKNT]

A few pounds per day is a small leak so take your time and look for tiny bubbles.

Brad

 

[Mellow]

Many times, a small leak like this can be the valve stem so concentrate on that as well.

 

[DirtFlier]

Is the "90 degree valve stem" the type with a long metal neck & rubber base that fits into the wheel? If so, this type seems problematic in regards to leaks.

 

[ett]

OP here;

Found it !

Thanks for the suggestions everyone !

Yesterday after work, right before starting this thread. I set the PSI of front tire to 38.
Today after work I checked the PSI. It was down to 28. That's 10 PSI per 24 hrs !

So I filled the bathtub with water, removed front wheel, set it's PSI to 50, and began placing wheel; vertically so as to not submerge the bearings; into tub.
With a minute or so I found leaking air bubbles at one spot between rim and tire bead. At a rate of about 3 bubbles per second.
I marked both the rim and tire at that spot. Removed tire, re-inspected both rim and tire.
Rim looked good as before. Tire appeared to have a slight wave in it's bead near; about 1 to 2 inches away; where the bubbles were leaking.

So I remounted the tire so that the marks on rim and tire were 180 degrees away from each other.
Placing the wheel back in the tub; I found the air bubbles to be leaking from the mark on the tire.

So rim good. Tire Bad.

I've never gotten a bad, new tire before.
I tried calling the online place I've bought it from. One of two places I always buy my tires.
But it's after business hours and they are closed.
So I bought another front tire from their website.
Perhaps tomorrow I'll call them to see if there is any type of warranty on tires.

Thanks again !


--ET

 

[seagrass]

Thanks for the update, always good to hear the outcome.

Seagrass

 

[ARKNT]

Hope there is some warranty on the tire.
I used bead sealant on a utility trailer that had a pitted rim but I wouldn't trust it to a bike tire/rim. Not worth it. I like my skin.

What brand of tire was it?

Brad

 

[ett]

Hope there is some warranty on the tire.
I used bead sealant on a utility trailer that had a pitted rim but I wouldn't trust it to a bike tire/rim. Not worth it. I like my skin.

What brand of tire was it?

Brad

Continental Conti Motion
I've been using these since they were first being sold in the U.S..
Never had a problem with them before.

--ET

 

[ett]

OP here;

Called the retailer this morning. It is Competition Accessories.
They do offer a warranty.

I have to send them photos of the bad tire.
It will take about 6 weeks to get full refund.
And I think (but not certain) they said they will send me a pre-paid shipping label to send the tire back.

They also said if I had not already ordered another tire last night; they might have been able me a free replacement.
And I would not need to wait 6 weeks to get refund.

--ET

 

[ett]

OP here,

Received new front tire this afternoon.
Mounted and balanced it.
Then stuck it back in water filled tub before putting wheel back on Griso. No leaks.

--ET

 

[Phil Tarman]

Since you don't have an NT to ride, it's gotta' be a relief to have a Griso to ride.

Be safe!