Ghetto Tubeless Tyre Conversion


Since I just have to have the trickest setups the internet can come up with, with the purchase of a “not embarrasingly shit” mountain bike off of Gumtree, I got to work on taking it to the next level.

First up was to ditch unnecessary things off the bike, like reflectors and the pump bracket. Bells? This baby wasn’t meant to be street legal.

Secondly, some velcro tape was cut to size and applied to the frame underneath the chain, as the most stylish possible way to muffle chain noise.

Thirdly, I ditched the plastic pedals that came with the bike for some better ones. It seems there isn’t much middle ground with pedals, they are either $20 plastic ones, or $150+ fancy anodised ultralight ones. I resisted the urge to colour coordinate, and found a pair of metal Jetblack pedals for $40. A quick trip to UNSW Bike club to borrow the pedal wrench, and a coat of lithium grease on the threads, and they were good to go.

Interestingly, while one pedal does have a non-standard backwards thread, to prevent unscrewing while pedaling, it’s not the side you’d guess first. Turns out the largest unscrewing force is not bearing friction, but precession! Apparently the famous bicycle mechanics the Wright brothers were the first to work this out, but it gets overshadowed by their other inventions, like the aeroplane.

Finally, it was time for the big one. Ghetto tubeless! What this is, is a way of making bike tyres airtight without inner tubes. Instead, a liquid latex mixture is used to form an airtight skin on the inside of the tyre, as well as being forced by air pressure into any leaks in the tyre or rim, sealing them on the fly. This is a great upgrade, as it gives you huge bragging rights online and at the trail head mandatory conversion, unless you are allergic to latex or have shares in an inner tube manufacturing company.

Seriously though, the usually quoted benefits are 1) hugely increased puncture resistance, from both rim strikes and sharp objects 2) allowing you to run low pressures, which means more grip, and 3) a more easily deformed tyre, which means less rolling resistance, better small bump compliance, even more grip, and a better “feel”.

To do this I needed:

  • Stan’s No-tubes sealant, from Summit Cycles. Thirty bucks.
  • standalone bike valves – I got Joes valves from Pushys as they came with a schrader (car tyre) valve adapter and valve core removal tool included.
  • Super Blue bear tape from Bunnings to seal the spoke holes.
  • Iisopropyl alcohol (also from Bunnings) and some paper towel, to properly clean the rims.

After cleaning the rims, cutting and applying the tape, screwing the valves in, and wrestling the tires back on, it was time to head down to the servo on the corner for some serious air pressure. You can try this with a floor pump, but every time I’ve tried, I just ended up with a sore back, Stan’s dribbled all over the floor, and the tyre flopping defiantly around the rim, refusing to hold even a single squirt of air.

Sealed front tyre with some sealant leaking out

The next steps are kind of like making a bottle rocket filled with spunk. Fun, and sexy.

  1. Take the valve core out of your valve stems.
  2. Punch the servo air compressor to 60psi, pop the adaptor into the pump nozzle, and hold it all up against the valve.
  3. Hit the “Flat Tyre Only” button to get it started. Hopefully (fingers crossed touch wood hope to die) the tyre seals quickly and starts inflating. If not, it’s probably time to start complaining on the internet.
  4. With the Presta valve core removed, the auto pressure gauge should work properly, and safely stop when you get to 60psi. The tyre makes scary popping noises as it’s forced against the rim and seals.
  5. Pull off the pump nozzle and quickly put your finger on the valve stem, so you don’t immediately let out all the air you went to such effort to put in. Find the valve core and quickly screw it back in.
  6. Wave the wheel around a bunch, to coat the inside of everything with sealant, and fill all the small leaks. The best way to do this is, of course, to just go for a ride.
  7. Top up the pressure as required with a bike pump, and leave at 60psi overnight.

Once the tyres are sealed, it’s much easier to top up the sealant by taking the valve core out and squirting extra sealant in through the hole. This avoids having to break the latex seal that’s formed around the rim.

Drop your pressure to 20psi and go clean all the technical climbs at Menai!

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