How to fix a leaking tubeless plastic Optimist Dolly / Trolley wheel.

Having three Optimists on the go, we have noticed from time to time that tubeless Dolly tyres go flat for no apparent reason.

 There are three causes.

1. Valve leaks
2. Leaks from either the base of the valve stem or around the rim
3. Punctures in the tyre itself

First step is to determine where the leak is coming from.  Fill a laundry tub or bath with water, pump the tyre up using a car tyre compressor to 30 p.s.i., leave the cap off  and put in the water and note where the air bubbles are escaping from. 

If it is coming from the rim, note which side is leaking. If from the tyre, see punctures below.

Valve Leaks

If the air is coming from the centre of the valve, you will need a valve removal/cleaning tool from an auto part store. Probably worthwhile buying a new valve insert and replacing the one in the valve.

If the air is leaking from around the valve seat, either buy a new valve stem, or us some Loctite 567 to reseal the tubeless tyres valve stem fitting ( recommended by an Opti-parent - no personal experience with that product).

Rim Leaks

This is 99% caused by an accumulation of salt / sand and grass working its way between the rim and the tyre and are quite easy to repair as follows:

1. Deflate the tyre.
2. Push in the bead with your thumb around the rim side that is leaking.
3. Wash salt / sand / grass off with fresh water leaving inside of rim and the tyre that contacts this clean. 
4. Wipe off with a soft, dry cloth and ensure all dirt etc is gone.
5. Using a mixture of 50 % Dishwashing liquid and 50% water, brush inside the rim using a small paintbrush.
6. Re-inflate the tyre using a car tyre compressor or take it to the local petrol station ( don't forget the soapy solution and paintbrush!)
7. Re-immerse in water and check the re-seal.  Repeat if necessary.
8. If it hasn't worked, there may be a ridge of plastic inside the rim that is stopping a good seal. Try sanding it back a bit.  However, the tyre will be inflated when you purchase your Optimist Trolley and may just suddenly go down after a period of use.  It is much more likely to be sand  / salt or some foreign material working its way between the trye and rim.

Punctures

Punctures can be repaired with tubeless tyre repair kits from auto stores or by putting a tube inside the trye.  It's very rare for these to happen.  Rim leaks seem to have accounted for just about all but one ( valve seat) of the flat trolley wheels we have seen.

Good Luck!