By NicoV
#84685
Today my Bullet had a puncture in the rear tyre at a speed of 70 kmph. The rear began moving wildly from left to right, and it is a miracle that I didn't crash. The front wheel kept course and fortunately I did not panic. I have had punctures before, each time in the rear, but never so scary as today. I ended up on the left part of the road (Norway drives on the right side). If there had been a car coming from the opposite direction, then..... Fortunately it was a country road.
I had 4 punctures in 2 years. Twice on a gravel road and once the valve had been torn off the inner tube when riding uphill. I don't yet know what was the cause of this puncture.
I am very tired of this and am thinking of getting alloy wheels with tubeless tyres. I never had a puncture on my Yamaha Virago which drives on the same roads. Is there anyone who converted to tubeless on an older Bullet ? Mine is a Bullet 500 from 1999.
#84693
I had a problem of frequent rear punctures on my 350. The last time was 6 miles from home in a rainstorm. I limped the bike home at very low speed in heavy traffic..not something I want to do again.

I eventually found a small raised "tag" of metal on the inside of the rim, which was biting the inner tube. I ground it off and as well as fitting the rubber rim tape I wrapped a couple of layers of duct tape over it. I've had no problems since.

The usual cause of the valve pulling out is too low a tyre pressure. The tyre slips on the rim. These days I fit a pice of rubber tubing over the valve and then gently tighten the nut onto it. This allows the valve to move slightly if the tube moves around the rim.
By Adrian
#84695
Is there anyone who converted to tubeless on an older Bullet ?
Er, yes! Not A Fury runs Avon AM26s tubeless with these wheels. Indian forks and swinging arm on this bike, so the Indian Bullet alloy wheels slot straight in.

A.
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#84707
I wonder. Are you getting the tyre beads fully seated on the rim? It can take quite extreme pressure sometimes (90-100psi on occasion, with the valve core out). Just your valve failure is, as stated above, classic of a tyre moving round on the rim.

For this reason, I never screw the "nut" you get on the valve stem down against the rim. I use it to hold the valve through when fitting then screw it back up against the dust cap. Then if the tyre move slightly, you might see the valve stem sitting at an odd angle before a total failure occurrs. The only reason I leave the nut on is to prevent the valve disappearing inside the wheel if I get a complete flat.

What do the punctures look like and where are they happening? This will generally give you a good idea of what caused them which in turn suggests how to prevent them.

One that you frequently see on push bikes is a "snake bite" puncture where you get two small cuts/holes close together. This is where an underinflated tube gets trapped between the rim and the road when you go over a compression. A stratight hole on the outside of the tube is more likely to be a true puncture and a cut is more likely to be a foreign object inside the wheel or tyre. A hole on the inside of the tube is more likely to be a sharp defect on the rim.

I had a couple of punctures one after the other and it turned out to be the valve washer off one of the old tubes had been left inside the tyre (by me) and took some time to wear through it.

Solutions? Make sure pressure isn't too low. If you are running a lot with low tyre pressures for offroading, consider fitting a rim-lock. If they are straight punctures, there are a variety of additives you can put in the tube that should prevent a catastrophic deflation. Two I know of are slime and linseal.

If you're getting snakebites, your pressure is way too low for tubes, if you're running that low you should consider fitting a mousse (but that would be unsuitable for ON road).

I always thought BMW came up with the best solution. They make tubeless spoked rims where the nipples fit outside the bead seat. I always thought this was an elegant solution but I suspect it would cost more than the bike to have a set custom built onto bullet hubs. You'd probably have to customs drill a set of rims to fit.

The follwoing article may be interesting:
https://www.advpulse.com/adv-products/c ... ed-wheels/
By NicoV
#84710
@Stinkwheel, thanks for your answer. I just removed the inner tube, and could immediately see the valve has been torn from the inner tube. Last puncture was approx 6 weeks ago, and there the valve was also torn from the inner tube. So, now I need to find a way to stop the tyre from moving on the rim.
#84714
What are you using as a lubricant when fitting the tyre? If it remains slippery, rather than drying off, it can cause a problem.

I use liquid hand soap and water, or window cleaning spray because I can never remember to put proper tyre fitting soap on my shopping list.
By NicoV
#84715
@Wheaters: until now I always paid someone to do it. Only this time, I was very curious to find out what was the cause, and removed the tyre myself. I will again go to a shop to have the tyre installed again.

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