Rear tire losing air

[destrago]

Here's one that's stumping me. On my commuter bike (a road bike) I've been having issues all season with my rear tire slowly losing air. By slowly I mean about 15-20PSI a day. I fill it to 100-110 in the morning, ride to work, ride home, next morning it's at 75-80psi. If I don't refill it, the next day it's at 40, and down to around 20 after that.

Here's the fun part. This is the 3rd tube I've had in there, all 3 doing the same freaking thing! About the only thing I can think of is that all 3 of these tires were purchased at the same time and I got 3 straight tires with manufacturing defects. Front wheel is an older tube which I've had no problems with. I fill it to 100 psi and 3 weeks later it's at 100psi.

Anyone seen this or have anything I should look at? I'm confused.

-Tony

[Steven W.]

Here's one that's stumping me. On my commuter bike (a road bike) I've been having issues all season with my rear tire slowly losing air. By slowly I mean about 15-20PSI a day. I fill it to 100-110 in the morning, ride to work, ride home, next morning it's at 75-80psi. If I don't refill it, the next day it's at 40, and down to around 20 after that.

Here's the fun part. This is the 3rd tube I've had in there, all 3 doing the same freaking thing! About the only thing I can think of is that all 3 of these tires were purchased at the same time and I got 3 straight tires with manufacturing defects. Front wheel is an older tube which I've had no problems with. I fill it to 100 psi and 3 weeks later it's at 100psi.

Anyone seen this or have anything I should look at? I'm confused.

-Tony

In your last paragraph you said "this is the 3rd tube i've had..." but then you talk about tires later on. Have you checked the tire for thorns or small rocks penetrating the tread? Just a thought...if something is in there it'll continue to put tiny holes in your tube.

[destrago]

In your last paragraph you said "this is the 3rd tube i've had..." but then you talk about tires later on. Have you checked the tire for thorns or small rocks penetrating the tread? Just a thought...if something is in there it'll continue to put tiny holes in your tube.


Yup. I've taken the tire entirely off and felt through the inside. I ran my finger through it to feel for ANYTHING and got nothing. Also, the tubes that come out of it still hold air when not in the tube, so it's not like it's a mostly sealed puncture so far as I can tell

-Tony

[MisterClaw]

Yup. I've taken the tire entirely off and felt through the inside. I ran my finger through it to feel for ANYTHING and got nothing. Also, the tubes that come out of it still hold air when not in the tube, so it's not like it's a mostly sealed puncture so far as I can tell

-Tony

What tubes do you use?

[Ish]

First options:

A) swap front tube to back and see if problem persists.

B) buy new, different tube for rear and see if problem persists.

If problem still exists, purchase new rear tire (commuter tires s/b cheap to get).

You could also try dunking the rear wheel in water to see if any bubbles indicate where the leak is, but is sounds pretty slow.

[Paul Swenson]

I had a similar problem. Even went to the extreme measure of have a shop fix it. Still went flat. Put on new tires and alls been good.

[destrago]

What tubes do you use?

The Bontrager tubes Penn Cycle in eagan sells.


First options:

A) swap front tube to back and see if problem persists.

B) buy new, different tube for rear and see if problem persists.

If problem still exists, purchase new rear tire (commuter tires s/b cheap to get).

You could also try dunking the rear wheel in water to see if any bubbles indicate where the leak is, but is sounds pretty slow.


yeah - I haven't dunked it, it seems too slow for that. I hadn't thought of swapping front to back tubes, good idea. I've been wanting to not mess with the front wheel since it's been perfectly happy. The tires I ride on are not all that cheap, but they're nice. I forget what they are, Matt got them for me.

-tony

[MisterClaw]

The Bontrager tubes Penn Cycle in eagan sells.



yeah - I haven't dunked it, it seems too slow for that. I hadn't thought of swapping front to back tubes, good idea. I've been wanting to not mess with the front wheel since it's been perfectly happy. The tires I ride on are not all that cheap, but they're nice. I forget what they are, Matt got them for me.

-tony

Are those the XXXLite bontrager tubes? If so, they leak like sieves. I've seen them lose 10+ psi/day.
Next, I'd dunk the tubes in water to check for pin-prick holes or leaky valves. Blow the tube up to slightly larger than your tire, this will cause any tiny hole to leak more visibly.

[destrago]

Are those the XXXLite bontrager tubes? If so, they leak like sieves. I've seen them lose 10+ psi/day.
Next, I'd dunk the tubes in water to check for pin-prick holes or leaky valves. Blow the tube up to slightly larger than your tire, this will cause any tiny hole to leak more visibly.

I don't think so. They're just the standard tubes - nothing fancy, nothing expensive. I'm not exactly a weight weinie for my commute. I'll dunk the tire I pulled out about 2 weeks ago, it's hanging from a hook in my garage right now. I'll probably dunk the tube that's in right now when I change them too.

-tony

[RiverRat]

If you have had the same issue with 3 consecutive tubes on the same wheel, it's more than likely either a sharp spot in the tire, or a sharp spot in the rim. If you swap tires front and back, and the problem follows, it's the tire, if not, it's the rim.

[BG128]

I work in an auto shop forget dunking the tire on a slow leak it will drive you nuts & you will never find it. Get a spray bottle put a little dawn dish soap or whatever dish soap you got spray it down then just watch for the bubbles to grow. It works almost every time even on very slow leaks( it may take time to start seeing bubbles but they will show up sooner or later.

[RiverRat]

The freewheel site mentions that they got a bad batch of bontrager standard tubes from china (at the bottom of the home page). They are doing a recall. Maybe this is your issue.

http://freewheelbike.com/index.cfm

[bigwheel]

In general, I have not had very good luck with the Bontrager 29er tubes. The LBS has them at a nice price, but I'd like a tube that doesn't flat without good reason.

My current favorite is the Quality brand tubes. They are reasonable price, not too overweight, and they seem to be way better quality and consistency. I think that they are actually made by Kenda.

[Cars-R-Coffins]

The freewheel site mentions that they got a bad batch of bontrager standard tubes from china (at the bottom of the home page). They are doing a recall. Maybe this is your issue.

http://freewheelbike.com/index.cfm
Penn had the same problem.