Slow leak in tube?

Brad Marcus

This may be a simple fix, but before doing so I figured I throw it out there to group in case I'm missing something. I recently installed a new tire and tube on my rear wheel after pulling the bike off many months on my trainer. I've done a handful of rides with no problem, but today when checking my tires pre-ride I noticed that my back tire had very little air. I found this strange since I had last ridden it only a few days ago. I pumped it up and inspected and it seemed fine. Halfway through my ride I pulled over and check the tire and it seemed a bit soft but not flat. I got home and checked it a few hours later, and it is flat again.

So apparently I have a slow leak, which I've never encountered with a bike before. Other than a fine pin hole, could something else be causing this before I go ahead and make the change? Could it be related to the tire as well?

I know this seems like a simple question to most, but since I'm racing this weekend, I want to cover all bases..... thanks!

GAndrew Gordon

did you make sure the presta valve was turned all the way tight?  leaving it loose may result in a slow leak.  if all else fails and you are dying to know where the leak might be, fill bathtub and submerge tube.

Darren Freeman

If you have tube extensions or tubes with removable presta valve cores you might want to take some Teflon plumbers tape and wrap the threads.

William Jenks

Ditto on both counts. Not that this is the case, but I find with valve extensions using removable valve cores, you really have to be sure to tighten the little valve knob. Teflon helps I agree.

Since you're racing, I think it might be worth checking the tire. Get it off and really run your fingers along the inside of the casing just to be sure there's no little notches or rough points. (or pebbles!)

Steve Ross

All good advice Brad. I have had unknown slow leaks as well before. As per Jenky advice and install new tube ! Go for a ride and monitor tire that is too much of a leak than normal loss !

 

harrast

x many. Take no chances. Install a new tube and test it out. With the pressure of our tires, almost anything can work its way through the inner tube and cause a slow leak. All the usual suspects have been mentioned. BTW, when my bike came home from the shop last I found a ball bearing inside the tire. Funny things happen at the bike shop.

Paul Hough

I had a slow leak on a tube recently. It was old, and would hold air for less than a day, so I changed it out for a new tube. But I checked the old one (filled it with air and then run the tube through a bowl of water) and it had developed a pin hole leak along the seam. Pitch it!

Brad Marcus

Thanks for all the great advice, team. I installed the new tube this morning. In doing so, I did a close inspection of the tire, wheel, tape, etc. Everything looked ok. Went for a quick spin with the new tube and as of now, everything is in good shape. I'll re-check tomorrow, but I'm 99% sure it was just the tube.....which makes it easy!

Brad Marcus

Oh...and for thr record, I do not use valve extenders. I find that too many issues can occur with those and why not just use tubes with long valves instead?

Paul Hough

At Brad - I use long valve tubes for my Enve 45-65 wheels, but my Enve SES 8.9s require valve extenders...they don't sell tubes with valves long enough to go that deep. All that is necessary is to use removable valve cores and that thin white tape that prevents leaks.