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Tyre Truble

Discussion in 'Technical and Troubleshooting Torque' started by SANZY, May 28, 2005.

  1. Hi All,

    I own a GPX250 and it had a Bridgestone Bt45r on the back tyre.

    Now the GPX is meant to have a 130/80 16 tyre on it but the BT45 is 130/90 16.

    This is not the problem as every where i look every one says to use the BT45 for this bike. Problem is my back tyre keps losing presure. I fil it up to 36 PSI as per the tyre chart and then by the next day or even that afternoon it will be flat and i will use the same servo to fill the tyre but it is down to 15PSI

    What could be casuing this? there is pleanty of tread on the tyres but at my P's day the instructor said the tyre looked old ? not sure what he meant but i can not think of what has happened. I am booked in for a new tyre on Tuesday and will ask them to check the old one but is there any idea what may cause the presure lose?

    Thanks guys

  2. A leak?

    You may have a slow leaking puncture.
    You may have a valve that is faulty and leaking.

    Try spitting on the valve and see if it bubbles at all.
  3. Spray a little window cleaner about any suspect areas (valve stem, bead), it will froth up where there is a leak.
  4. I've had punctures where the piece of metal was so small that I really had to look for it.
  5. Thanks for the replies i had not thought of using the window cleaner spray bottle so will try it.

    I have checked the valve but spitting on it but it looked fine.

    Have checked the tyre for a punture but could not see anything.
  6. Well,

    After reading mothra's surjestion of using windex to spray the wheel with i tried this and found a small air bubble happening.

    Took the bike to the place i had booked the tyre change into and had a word to them they checked it and said yep a small leak. $10 latter they fixed it and said they would can the order for the new tyre so thanks to all that have helped me with this.
  7. That's good to hear.
    I've finished work now and I'm off to drool at the motorcycle shop. :D
  8. Glad to hear you found the problem. My suggestion would have been the wheel rather than the tyre, today's tyres are very reliable.
    But cast wheels can develop leaks especially as they get older. The castings become porous and start to allow air out.
    Keep an eye on the wheels and you shouldn't have any more problems.