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Slow leak - front tire

S Smith

Northeast Area Director
Member
I have a slow air leak in the front tire. It was there with the last two set of tires also. The source of the leak is eluding me.

New tires were mounted SAT along with new 90-degree valve stems. The guy mounting the tires made sure the wheel bead area was sufficiently clean, none of the nibs were stuck in the bead, and he spent extra time checking the bead for leaks. The next day I installed the wheels and when I checked pressure the front was low.

Sunday evening I spent a good amount of time with a spray bottle of soapy water and a bright light exploring for leaks at the bead and wheel. The end result so far is that I have lemony fresh, clean hands, but no leak found.

Can someone pls share wisdom on where to look or what to try.
 
Submerge it in water.
Yep. That was going to be the next step. Was hoping to hear a new to me on-bike diagnostic to check the wheel. Haven’t heard of any wheel failures / stress cracks posted up here. Was wishful someone else might have experienced the same issue/symptoms.
 
All tires leak air, but I manage to significantly slow the leaks by cleaning and polishing the beads myself, to perfection. I also make sure the valve stems air valves are clean and tight. The valve stems must be perfectly mounted as well. If you don't clean these areas to perfection, then you will never know. Submerge the tire under water is the only sure way to locate the leak.
 
I’m constantly having to add a couple pounds literally every day since installing the Road III front and Road II rear. Doesn’t matter if I’m riding or not, these seem to leak with regularity. Don’t recall my previous two sets leaking at all last summer, but with spring and fall overnight temps changing I was losing a bit during the week but nothing near as quickly as these.
 
My 2014 loses a couple of pounds a week in both tires and always has. My Goldwing on the other hand rarely needs air . My son’s VStrom had a leak in the rear valve core so we replaced the core. Fixed it.

Now I’m wondering if I should replace the cores in the C-14. Anyone know if the tpms cores are just standard Shrader cores and to your point, have you tried that?
 
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My 2014 loses a couple of pounds a week in both tires and always has. My Goldwing on the other hand rarely needs air . My son’s VStrom had a leak in the rear valve core so we replaced the core. Fixed it.

Now I’m wondering if I should replace the cores in the C-14. Anyone know if the tpms cores are just standard Shrader cores and to your point, have you tried that?

standard Schrader

from the OP, the valve assy was replaced with new 90-degree parts from Murph.
 
It has always been my impression that the TPMS valves leak a bit more than normal. I have 5 bikes and the 3 other tubeless tire bikes hold their pressure better than the 3 Concours 14s I have owned. I have always had to add a pound our two about every 10 days. The KLX 250 with tubes also loses a couple pounds in two weeks. My R1200RT, Multistrada and R3 all hold presssure at least 3 weeks. By the way, the RT also has OEM TPMS.
 
Boy, that's a tough one Steve, water looks to be your friend, I lose about a pound a week on my new '22.
 
Boy, that's a tough one Steve, water looks to be your friend, I lose about a pound a week on my new '22.

Agree... I feel 1-2 psi per week is acceptable.

The previous set of tires that were just unmounted lost approx 2-5 psi per week. I did not track it.
New tires left the shop SAT afternoon supposedly with 40 psi. SUN afternoon tire was 31 psi.
SUN evening tire set to 40 psi by my gauge. Was 38 psi this evening. Way better than day 1.
Will monitor daily and see what happens. Maybe the issue was using 2 different tire gauges.
If after a fews days of monitoring the psi loss is greater than 1-4 psi per week, I will put the wheel in water.

Thanks guys... I'll report back after a few days of monitoring.
 
Different tire gauges throw me off. My most accurate is a shorty that I picked up at Eally world in the tire dept one day. I try to use the same one on the same bike every time.
 
WOW, I must have some special wheels, tires or stems as I very RARELY need to add air, maybe once a month or even less - and yes I monitor the air pressures.. 🙄

My guess would be around the bead somewhere there’s a tiny bit of guck. I would not think a stress crack (back from experience with pipe and welding inspections) in the wheel would be this little of seepage.

Good luck, do share!

Wayne, Carol & Blue
 
WOW, I must have some special wheels, tires or stems as I very RARELY need to add air, maybe once a month or even less - and yes I monitor the air pressures.. 🙄

Wayne, Carol & Blue
Hey, when we do eventually get to ride together, please lay your hands on my bike and think positive no-air-leakage thoughts!:giggle::giggle:
 
I don't see tire pressures fluctuate widely with my concourse with TPMS or with my Vstrom (without TPMS). With that said, I do my own tire changes on both bikes and introduce my consistent amount of tire lube containing water (because it's me). Each time I replace the schrader valve with a new one and replace the valve stem o-ring as well as giving each a bit of petroleum lubricant for the valve set o-rings.

I am not suggesting this is a best practice, it is just what I have done and I rarely have to top off my tire pressure.

With that said I set my PSI to cold to tire specs with each tire change. I check that the next day (air compression from filling has contributed to air heating) and added or eliminated air as needed, and again at 7 days ( doing the same and riding the bike each day).

If I were to see a reliable and repeatable 1-2 PSI drop in tire pressure each month I would change out the schrader valve and the valve stem o-ring. If you are still loosing PSI, hold the entire wheel under water and wait for the bubbles.....for a slow leak it will take some patience and observation.
 

A quick read...

I don't think I've had a tire that didn't loose a pound or two a month 😒.. Might be that high humidity Kentucky compressed air...hummmm....I do have a nitrogen tank though....
 
3 month follow up...
The air loss seems to have normalized to 1-2 psi per week. It it possible an undetectably small leak at the bead sealed. In addition, I began checking tire pressure weekly instead of daily, and I exclusively used one tire pressure gauge, and not the one built into the battery powered pump.
 
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