rear tire pressure goes down to 25 or so psi if it sits 2 days or more.

[gunpilot75]

Been that way since new (it's got 4700 miles now). I put 40plus into the rear and ride. come back, still 40 plus....sits a day or 2 days really and it's down to 25 psi. Never goes below that. Any idea why?

 

[Bob R]

I would be looking at a bad valve stem, or a bad tire to rim seal due to debris or corrosion. It could also be a very small puncture but seeing how it was there from new that may not be the cause.There just isn't that many things to cause an air loss so it should be straight forward to find it. Valve stem issue, bad bead to rim seal, puncture, bad wheel (unlikely).

bob

 

[Gimlet]

Almost certainly the valve stem. If so, it will leak faster when the bike is parked with the valve at the bottom of the wheel where the weight of the bike applies greater pressure. Try parking with the wheel in this position and with it opposite with the valve at the top of the wheel. If the tyre loses more pressure or loses it quicker with the weight of the bike on the valve area, that is 100% your problem.

It could be the valve itself or it could be the valve seat against the rim. I would think the seat is more likely, though faulty valves are not unknown.

 

[Kiwicol]

You could try a new valve core, they cost cents and is very quick to do. Least you'd eliminate a faulty valve core if nothing else.

The core has a wee spring pressing against the seal, could be an issue with this area?

 

[A1A Rider]

1) Bring tire to proper pressure. Bring the bike somewhere close to a water hose.

2) Make a soapy water (dishwashing liquid), like very soapy, and use a wet cloth to distribute over the tire. You'll see bubbling right away. The air letting out spot will look like an angry ant house.

3) Notice where it lets air out, mind that there might be multiple spots. Mark or take pics of the spots.

4) Make sure to hose off the tire very well afterwards.

 

[Kiwicol]

Yep, that'll work. Alternatively, it's the rear, take the wheel off & stick it in a kids paddling pool & look for bubbles.

 

[Journeyman]

A spray bottle with soapy water may show you the location. Be sure to also take off the valve stem cap and spray into the valve. It may simply need to be screwed in tighter (my bet). While riding the pressure will rise, so you have a small/slow leak. It’s one of the places @Bob R pointed to.

 

[TURBO200R4]

Been that way since new (it's got 4700 miles now). I put 40plus into the rear and ride. come back, still 40 plus....sits a day or 2 days really and it's down to 25 psi. Never goes below that. Any idea why?

My guess is when they mounted the tire they broke the bead on the tire
If this has happened then replace if under guarantee if not I have used black silacone a couple of times

 

[Kevin frazier]

Since new, as in 0 and it now has 4700 and you refill to 40 plus to ride. Did the dealer say anything when they check it. Replace at whoevers cost tire is shot, 4700 and up and down im guessing 10 times. Life is short, dont go out because of a 250 dollar.

 

[Kiwicol]

Turbo mate, you are never gonna break a bead on a tire. You can surely break a bead away from a rim, (it's a process) but you will never break a tires bead. It's made of lots of wires encased in rubber and wound into a circle. Then ends are then either pressed into each other or the bead is spiral wrapped with strong nylon line . No leverage from any tire fitting tool will break the bead wires, just not possible.

I used to make tires n beads n steel belts n tube's etc.