ugh...came out to a flat tire!

[Iahawk]

as the title says...I was just out in my garage for no real reason other than to look over my bike and scoots..and upon closer inspection noticed the rear tire on my Helix was flat. I last rode it 2 days ago, put on 33 miles on Sunday (and I aired it up before the ride).

I looked closely at the tire and couldn't see any sign of a puncture or tear. I then put it up on the center stand and started filling the tire with air in hopes of locating the leak. At 15 psi..nothing..at 30 psi..nothing..upped it to 34..still nothing.

Removed the air hose and heard the dreaded psssssssss. The air was leaking out of the valve stem. It's like it wasn't sealing. I thought this might bite me...when the tire was replaced last June of '21 they reused the old valve stem as they said they didn't have any 90 degree stems in stock.

Taking the rear wheel off involves a lot..bodywork removal, muffler removal (which means a new Honda exhaust gasket). Better to find this out in the garage than by the side of the road.

[NorWeWa]

As you said, "best to find this in the garage". If it's any comfort, removing the tire off my Downtown 300i was more involved than doing the valve adjustment. Needed to remove the right rear shock, which added removing the seat and cargo tray, 

Art 

[rjs987]

Most good 90 deg valve stems are metal. Usually CNC Aluminum. Should be no need to replace at every tire change. In fact, those metal stems should last for several dozen of tire changes with no issues.

One thing to consider is if the air is leaking through the core you should be able to just get another core. Those are common to almost any valve stem... straight rubber or angled metal. No need to remove the tire if that will fix it. Just use a core tool to take out the old core and insert a new core. No need to remove the wheel or any other disassembly. Easy to do. The most you'll have to do other than replacing the core is to let all the air out and then refill the air.

[randyo]

they reused the old valve stem as they said they didn't have any 90 degree stems in stock.

 Last time I had a tire changed at my local dealer, they sent someone up the road to NAPA to get a valve stem. not the only time they've been to NAPA or had something delivered

I hate going out to a flat, been there, done that

[Iahawk]

RJS, you may be on to something..yes, it's leaking through the core...and I think I do have a core removal tool, somewhere. The old stem is still 10+ years old and made of rubber..(old tires were date coded 10..or even 12 years old?).

If I can fix it I'll probably end up needing a new tire at the end of next season, based on current wear (10 inch rear Helix tires don't last long). I can live with the old valve stem until then. I'm assuming an auto parts store will sell valve cores? Heck, I even have tires stores nearby..

edit: found this core removal tool and cores in a tire repair kit I have..

[rjs987]

Maybe time to order a set of metal 90 deg valve stems for the next tire change. (need to know the hole size in the rim).
Just use the core swap for this time.
Rubber valve stems don't last so long. I do think it a good idea to swap rubber valve stems at least every few tire changes. I've never had issues since I replaced the valve stems with metal angled stems on every bike I've owned long enough to need the tires replaced.

[Iahawk]

OK, tire air'd up and it appears to be holding. Thank you, RJS. You were correct, the 90 degree stem was metal (brass?). For some reason I was under the impression that the threads were metal but the stem was rubber..maybe because it's always been black with crud?

Simple to unscrew the old core and thread in a new one. (well, simple after I put the 4 way core tool in my vise and pounded out the 'cross' piece, which wouldn't allow the tool to turn in the very tight space on my Helix back wheel).

New core screwed in. Tire air'd up. I'll check tire pressure in the morning.

Learned a new skill today and it cost me $0!

[Iahawk]

and here's the tight space on a Helix rear wheel / valve stem...

[Stig / Major Tom]

Remember the black plastic tire valve caps -----turn it over and it became valve/stem core removal tool.
Also....there are tire valves which can be installed outside the rim - without removing anything but the old valve stem.
I'm running one in my Liberty's back wheel. Holding air just fine for a couple years now.
Stig

or these....

[NorWeWa]

Good the problem was an easy fix. I have also found the valve core just loose, and with tightening to fix a slow leak. Careful not to over do it.

Art

[rjs987]

OK, tire air'd up and it appears to be holding. Thank you, RJS. You were correct, the 90 degree stem was metal (brass?). For some reason I was under the impression that the threads were metal but the stem was rubber..maybe because it's always been black with crud?

Simple to unscrew the old core and thread in a new one. (well, simple after I put the 4 way core tool in my vise and pounded out the 'cross' piece, which wouldn't allow the tool to turn in the very tight space on my Helix back wheel).

New core screwed in. Tire air'd up. I'll check tire pressure in the morning.

Learned a new skill today and it cost me $0!

Fantastic!
And you still have another spare core should this ever happen again.
Imagine how much the shop would have charged you to fix this. I am fairly certain they would not replace just the core but replace the stem with a new one just to show they did something, and then charge a lot of labor to do it.

[Iahawk]

Fantastic!
And you still have another spare core should this ever happen again.
Imagine how much the shop would have charged you to fix this. I am fairly certain they would not replace just the core but replace the stem with a new one just to show they did something, and then charge a lot of labor to do it.

yes, thank you, you probably saved me a few hours of work and at least a $100 bill from the dealer!

[CROSSBOLT]

See? This forum just paid for itself! That's the way it works, people! Yahhoo!

[rjs987]

Remember the black plastic tire valve caps -----turn it over and it became valve/stem core removal tool.
Also....there are tire valves which can be installed outside the rim - without removing anything but the old valve stem.
I'm running one in my Liberty's back wheel. Holding air just fine for a couple years now.
Stig

or these....

I do remember those caps. Have had them on a bicycle once. My AK has plastic caps similar to that. The valve core removal tool is recessed into the end of the cap. Screw it on one way to seal the valve. Turn it over to remove the stem core.