Back tire has a slow leak I can't find. What to do?

[romnation]

I think my back tire has a slow leak I can't find. After one week it loses about 7-8psi of pressure while my front tire loses none. These are Michelin City Grip btw. I've tried locating the source but no luck. Is this something that is repairable or will I need to replace the tire? Will a normal tire shop be able to take look at this or do I need to go to specialized scooter/motorcycle shop? Also if I do have to replace do I need to replace both tires as they will have different amounts of tread wear? (got about 3k miles on this set of tires)

Thanks

[relic]

Put your bike on the centre stand rotate the tire while spraying soapy water on the the tire and bead-look for bubbles.
if that is where the leak is take to a tire shop.
Put a little spit on your finger and place it on the valve stem- if it bubbles there try tighting or replace

[alx123]

My money is on the tire valve leaking a little. Easy to fix. Do the spit test as relic mentioned first.

[romnation]

Put your bike on the centre stand rotate the tire while spraying soapy water on the the tire and bead-look for bubbles.
if that is where the leak is take to a tire shop.
Put a little spit on your finger and place it on the valve stem- if it bubbles there try tighting or replace

I assume this is the same logic as the soapy water test right? I tried doing the soapy water test and was still unable to locate any bubbles anywhere including the valve stem. Maybe I need to air the tire up to max to find it easier? Does anyone know the max psi on the city grip? I can't find it anywhere on the tire (maybe I'm blind?) or online.

[iceman]

When I had my rear tyre changed from a trusty IRC (worn out after 13,000+ miles) to MCG, I was losing about the same as you for a few weeks and now it's settled down to the typical 2-3psi or so every 1-2 months. I gather it took time to seat properly and seal up.

[springer1]

My money is on the tire valve leaking a little. Easy to fix. Do the spit test as relic mentioned first.

+1. If it bubbles, go to an auto parts store and buy a little box of valve stems (sometimes called cores). Also - if you don't have a valve cap with the 2 little prongs that help unscrew the stem, get one of those too. The stem screws right out of the valve and a new one back in. BUT BE CAREFULL when you unscrew the old one as the air pressure will shoot it out with force if you don't deflate the tire first.

https://www.rockymountainatvmc.com/tire ... -remover-p

Most valves use a standard stem/core, but if you take the old one out first, you can then match it up. Just deflate the tire first so it doesn't rocket off when you unscrew it.

[Mel46]

I don't know if this works on modern tires but when I was much younger and my tire had a slow leak no one could find this is what the garage did. (Like I said, I don't know if you can even do this now.)

The mechanic let all the air out of the tire. Then they unscrewed the valve stem and poured about a cup of colored water (he used bright green food dye left over from Easter egg dying) into the tire through that little stem. (That was a job in itself.) Then he put the valve stem back in, aired up the tire, and rotated it in a small trough of water until the water started coloring. Then he pulled it out of the water and looked for the hole in the area the color was coming from, running some clear water over the suspected location and then rotating it slowly so that the suspected area would have the inside water covering it.

Before doing all of that, I would check the valve stem. Between it and the bead, there is a good bet that you will find the leak.

[Jge64]

Put a can of RIDE-ON into the tire…It’ll stop the leak and balance the tire. Works very well , I’ve used it on all my tires.

https://www.ride-on.com/us/support/tire ... le-formula

[fish]

Put your bike on the centre stand rotate the tire while spraying soapy water on the the tire and bead-look for bubbles.
if that is where the leak is take to a tire shop.
Put a little spit on your finger and place it on the valve stem- if it bubbles there try tighting or replace

I assume this is the same logic as the soapy water test right? I tried doing the soapy water test and was still unable to locate any bubbles anywhere including the valve stem. Maybe I need to air the tire up to max to find it easier? Does anyone know the max psi on the city grip? I can't find it anywhere on the tire (maybe I'm blind?) or online.

Max PSI is on there....(never meant to be the "riding"PSI though !)

Fish

[Martin J]

I had a slow puncture on my car, so I removed the wheel and sprayed soapy water over both beads but couldn't find a leak. I went all round the tyre, checked the valve but found nothing.
As I was refitting the wheel, I suddenly had a brainwave and sprayed the base of the valve where it met the wheel rim, resulting in a load of bubbles. One new valve fitted and the tyre stays up.

[Old Grinner]

I had a slow puncture on my car, so I removed the wheel and sprayed soapy water over both beads but couldn't find a leak. I went all round the tyre, checked the valve but found nothing.
As I was refitting the wheel, I suddenly had a brainwave and sprayed the base of the valve where it met the wheel rim, resulting in a load of bubbles. One new valve fitted and the tyre stays up.

Oh yeah . . . valves can definitely tear at the base . . . thus causing a tear in the eye.

100_4879a.jpg

[you you]

Nice use of homophones

[springer1]

Nice going in finding the culprit !

[OldGuywhoTinkers]

A couple of thoughts: First, replace the tire stem with a new one when/as you replace a tire. Two, you really cannot patch sidewall damage. It won't work and it is unsafe. Three, many leaks that are NOT sidewall leaks can be permanently and cheaply patched by a simple pull through plug.

Green ''slime'' or a similar product can seal tiny leaks THAT ARE NOT IN/ON THE SIDEWALL. You need a valve stem remover. Remove the valve stem, you measure in the recommended number of ounces of stop leak, and the product works very well sealing tiny holes.

One last thing: some people are very rough hitting curbs and so on. Serious damage to a rim must be straightened out or the rim must be replaced.

[Poohstyx]

The standard shop method of finding a leak is to remove the wheel, pump it up, then submerge in a tank of water.
The max psi listed on the tyre is the max safe pressure for use, that is its definition.
For my PCX that is currently 41 rear & 33 front.
Been using this value on all my bikes for over 30 years since any bike with me on is overloaded
Over the years crap tends to build up on the beads, they should be periodicaly cleaned with a wire brush to maintain a good seal.
Find a local spanner monkey that fixes punctures properly and stick with 'em, most shops just 'slap the patch on and hope'. The inner surface should be smoothed & cleaned, then glued and left to go off before applying the self-adhesive patch and rolling.

[WhiteNoise]

Nice use of homophones

Today's word ^ dig it! thanks 2yous

and now
[quoting Old Grinner] "..... valves can definitely tear at the base... thus causing a tear in the eye" ... or a tear of the town (my input)

Re: Leak - Applause, Applause! Great advice given by everyone here
But I wanna play too...on topic but off it too....

Kings 'n Queens of the Barbie, @seasons start-up or when the tank is exchanged or refilled, use that Soapy Water technique before you fire her up, and later when funny odors aka gas are sensed. That spells Leak. Don't hit the Red button! Grab a tossable plastic cup, or a spray bottle - add 50/50 water and dish detergent, mix. Brush it on/over propane tank, it's valves and hoses. Look, are ya seeing Bubbles on the Rise? Then it's R/R time (remove and replace leaky part(s)

Smart BBQ tip. Thanks to me elders back in the day!

[mymitzi]

Noticed a slow leak in my front tire [about 2 lbs a day] Knew I had hit a pothole recently, Hmm.......took longer than it should have to discover
where the leak was. Took a large C clamp and [tire deflated] had a look and see. Was expecting damage to the bead but appeared to be some
organic debris that took the opportunity to get in there while the pot hole opened it up [guessing] Any way, a swipe with a damp paper towel seemed
to remove it. Thought, this is too easy.......removed the C clamp and aired the tire and Bingo [so far,anyway] No wheel removal needed! Thankful!