Much has been written about ways to lighten up a 36″ Wheel.  One of the quickest and most effective is to put a 29’er inner tube in your 36″ wheel.  The stock 36″ tube weighs about 500g, whilst most 29’er inner tubes weigh 250g or less.  The 29’er tube will stretch enough to fit in a 36″ wheel.

This may sound like a fairly straightforward excercise, but there are a few important points to note.  Stretching anything more than it was designed to vastly increases the possibility of an explosive outcome.  Ever tried overinflating a balloon? 

The ease with which you install the 29’er tube depends on the tyre/tube combination.  I have used the conversion with the current Nimbus Stealth Pro rim and Nightrider tyre, which works very well.  The bead can be installed with only minimal assistance from tyre levers (which you want to avoid).  Other tyre/rim combinations require much more effort and many expletives in order to install.  This makes the chances of 29’er tube installation failure a lot greater.

You can purchase 29’er inner tubes at most good bike shops.  Or they can order one in for you.

Points to note:

• Wear ear protection
• Avoid tyre levers if at all possible- if you pinch the tube during installation, expect it to explode
• Check your rim and tyre for any sharp edges.  Cover with ductape or insulation tape.
• Inflate slowly.  I normally inflate to about 20PSI, then deflate it and reinflate it.  This lets the bead and tube settle before inflating to riding PSI
• Carry a spare inner tube when riding.  The original 36″ inner tube is virtually bombproof…I have met very few people who have ever punctured one.  The 29’er tube on the other hand, can explode without warning.
• There are a variety of tubes.  Schraeder (car) valves are easiest because 36″ rims are all drilled for Schraeder valves.  Presta valves are more common on bikes, and this may be all you can find for 29’er tubes.  I use Tioga 29’er presta tubes.  Just put a couple of washers on the inside of the rim and on the outside to reduce the diameter of the valve hole.  You will need to stick down the washer inside the rim with with plenty of ductape/insulation tape to cover the sharp edges.  Poke a hole through the tape for the valve and away you go.

History of the 29’er tube and Tubeless 36″ Conversion:

First described by Ken Looi on this thread in Unicyclist.com.  First successful attempt by Tony Melton described in this thread.  Tony Melton first suggested the tubeless conversion, and Dirtsurfer the first to try it.  This is all summarised by U-Turn of Livewire Unicycles.