I check my tire pressure at lease twice per week on my '03 Ultra Classic and more often if I'm going any distance from home.

I had a new rear tire mounted about 1500 miles ago. The front still has the original tire on it.

Every time I check the tire pressure, it is always down 5 to 8 psi on the front and the back. I always check the tire pressure cold and spot check it if I've ridden any distance.

It seems like when I ride for any distance such as 75 to 200 miles and then check the tire pressure (road temperature) there is no pressure lose. It seems to only happen while in the home town area and when the bike is home every night that the pressure seems to drop.

Don't think this has happen on any other bike. This don't make much sense to me.

 

I'm guilty of completely forgetting to check my tire pressures for weeks at a time. I usually manage to check them once every 3-4 weeks. [&:]

Having admitted that (notice I did NOT ask for forgiveness! ), when I do check them, they have never lost more than 3 psi.

 

???
Hmmm...leaky valve stem maybe???...i'm just guessin...my front was losing aabout 4lbs a week cold..I loosened the valve stem and re seated it...seems to have worked in my case.

 

I would have to say a leaking valve stem aslo maybe, I check mine as often as your do and I stay at the same tire pressure before and after trips.
Only lost pressure one time and that was at 200 miles on my scooter and found a nail in my tire [:@] and to make it worse it was the day before I was leaving for the ROT ralley in Austin.

 

Just curious... Are you using the same gauge each time or does the gauge you are using have a check valve or Schrader type valve that prevents (or minimizes loss of air)?

 

Good point on the gauge. I've used lots of different brands/types of pressure gauges over the years for checking auto, scoot and bicycle tires. It's amazing how much gauges can vary...one brand/type or from another example of the exact same brand/type.

 

I've been using the new HD air pump and gauge. It's easy to use with the flexible hose on it.

I use it on my '04 F150 also, so I don't think anything's wrong with the gauge. It just seems strange that when I'm gone on the bike for an extended period of time and I check the pressure it is ok.

It only when it sits more than a day or two that the pressure seems to bleed off some how.

As best I can, I have used a spray bottle of soapy water sprayed on the bead and around the valve stem with no results.

I'll just keep checking the tires and putting air in them if needed.

Could both wheels have a flaw in the material. Anybody heard of that?

 

Unfortunately, you're not alone on this. I'm horrible about checking the air pressure. I ride everyday and end up just jumping on the bike and riding to work and back home again. I'll have to remember to check it this weekend.

 

Leaky valve stem likely to be the problem. You can loosen it and retighten or just replace the valve stem itself and see if that resolves the problem. I used to check them just by dabbing some spit over them and see if a bubble comes up. That's a pretty fast one to find out. Or you can stick a balloon over the stem and check it out over night. Secondly, I'd check the gauge itself. Third, but not likely, I noticed you said you were checking in the daytime before you ride and then after you have it garaged at night. I can't imagine there's enough temperature variation to make the pressure drop, but who the heck knows. Good luck...it's annoying enough.

 

If you are checking the pressure immediately after a ride, it is not likely to show a small net loss since that is hot psi and the pressure increases as compared to cold psi. SO if there is a small leak, hot psi may appear to be the same as cold psi, with some air loss, and no significant change in pressure post-ride vs pre-ride. The as the tire cools, the pressure loss will be evident next time you check cold psi.