Nimbus Nightrider Pro strange tire leak

I own a Nimbus Nightrider Pro 36er that I purchased in Jan of 2011 and haven’t ridden in a few months. Yesterday I went to inflate the tire and discovered it has a leak. The leak isn’t coming from the part of the tire that makes contact with the road or the sidewall. The leak is coming from the rim side of the wheel - the side where the value stem is located. The center of the rim is lined with 34 holes, each 1/2" in diameter. The leak is coming from one of these wholes.

Have any other Nightrider owners experienced a leak like this? If so, did you have to replace the tube? It seems impossible for the tube to develop a puncture in this location.

have you taken the tire+tube off the rim to check?
if not, the puncture could be anywhere on the tube, but the air will only escape thru the rim side b\c it isn’t airtight

Good point. I haven’t taken the tire or tube off the rim. Guess I’ll have to.

I had an air leak on one of my trike tubes. I removed the tube, only to find that the leak was coming from the valve.
I tightened the inner valve … leak fixed.

It’s worth replacing the standard valve cap with one of these, which also doubles as a valve core removal/tightener tool.

(You can also buy spare valve cores)

While not on a 36er I have had a leak on the rim side of the tube. I was riding xc at the time, no hops, the terrain was smooth, no foreign objects inside the tire, and no explanation. It just went flat while I was riding.

The best I could figure was that the rim strip was a bit off center and the tube could have punctured against one of the drilled out portions of the rim… even though there were no rough/sharp edges. That or it was a defective tube.

Just letting you know, it does happen.

+1 on that - Inner tubes get holes in them, sometimes it’ll make zero sense, sometimes you’ll discover half a tree stuck in it somehow, but you can always count on it happening!

The leak was in one of the dimples which forms inside one of the many holes inside the rim. I suspect the 34 holes in the rim are to reduce weight. There’s a liner inside the rim to prevent the inner tube from bulging out the holes, but it’s not enough. The inner tube forms dimples inside each hole in the rim. The leak was at the center of one of these dimples.

I’ve never liked the idea of drilled out rims on any form of ‘bike’.
Give me a solid rim every time.