POST EDITED TO ADD IMGUR PHOTOS (I was 'Photobucketed'):
I have been tinkering around with trying to break the bead on the rear tire of a C-14 on the bike, then push one side of the tire over enough to get the TPS sensor out without removing the tire / wheel ass'y from the bike. I have not been successful as I do not have anything large enough in the way of a clamp or any way to deliver enough pressure to the bead.
We really wanted to see if this could be done before tech day as it will save a considerable amount of time replacing the batteries in the TPS sensors if we do not have to R&R the wheels, and get each tire and wheel into the tire machine.
This is also useful for anyone who wants to remove his / her own TPS sensor and replace the battery or send the sensor out to have someone else replace the battery but does NOT have a tire mounting machine. This method is done with wheels on the bike and nothing but the centerstand (although a small jack would be needed to do the front wheel of course).
Working with Pat Mulloy on Sat., we found a method that does work though using very conventional hand tools: he had a beam clamp large enough that it would reach around the tire. This is a very conventional one- hand clamp found at Home Depot, Lowes or similar, for use as a woodworking clamp. The key to the method that Pat came up with is using tire irons in combination with the clamp. So this is how we did it:
You will need at least one beam clamp, able to open at least 8" or more. Also at least two tire irons and three pieces of wood about 1 1/2" or so thick to hold the bead in the wheel's well.
1) remove the valve stem Schrader valve
2) put the clamp over the tire at about a 15 or so degree angle (to the axle) so that one jaw firmly grabs the wheel rim and the other jaw just misses the wheel and pushes only on the tire bead. Make sure the position of the clamp is at least 90 degrees away from the tire valve stem so there is no risk of damaging the sensor.
3) compress the clamp as far as it will go- this was not far enough to actually break the bead but it did leave a gap between the tire wall and the wheel rim; at this point, use the tire irons alternately above and below the clamp to further push the tire away from the rim. As the tire is forced toward the center of the wheel with the iron, take up any slack with the clamp. Pretty soon the bead will be clear of the rim; at this point just move the tire away from the wheel enough to jam a piece of wood in the gap and then release the clamp. Rotate the wheel 90 degrees, further away from the valve stem, again use the clamp and if needed a tire iron to open a gap between the tire and the wheel and stick another piece of wood in the gap. Do this in three places about 90 degrees apart and finally rotate the tire so that the valve stem (where there are no wood blocks) is facing the back of the bike.
4) Again position the clamp around the tire / wheel and begin to move the tire sidewall toward the middle of the wheel. It will move easily now that the bead is fully broken; you only need to basically squeeze the sidewall of the tire. Be careful as the tire bead approaches the center as it will move right across the TPS sensor and may actually touch it. If it does touch it, slip a tire iron between the wheel center and the tire bead to gently lift it away from the sensor and keep squeezing the clamp; the tire bead will move to the far side of the sensor.
5) The sensor will be fully exposed at this point (easy boys!) so just reach in with a hex wrench, remove the valve stem body (from the inside) and take out the sensor.
This is what it looked like when everything was in position to get to the sensor:
I have been tinkering around with trying to break the bead on the rear tire of a C-14 on the bike, then push one side of the tire over enough to get the TPS sensor out without removing the tire / wheel a**'y from the bike. I have not been successful as I do not have anything large enough in the way of a clamp or any way to deliver enough pressure to the bead.
We really wanted to see if this could be done before tech day as it will save a considerable amount of time replacing the batteries in the TPS sensors if we do not have to R&R the wheels, and get each tire and wheel into the tire machine.
This is also useful for anyone who wants to remove his / her own TPS sensor and replace the battery or send the sensor out to have someone else replace the battery but does NOT have a tire mounting machine. This method is done with wheels on the bike and nothing but the centerstand (although a small jack would be needed to do the front wheel of course).
Working with Pat Mulloy on Sat., we found a method that does work though using very conventional hand tools: he had a beam clamp large enough that it would reach around the tire. This is a very conventional one- hand clamp found at Home Depot, Lowes or similar, for use as a woodworking clamp. The key to the method that Pat came up with is using tire irons in combination with the clamp. So this is how we did it:
You will need at least one beam clamp, able to open at least 8" or more. Also at least two tire irons and three pieces of wood about 1 1/2" or so thick to hold the bead in the wheel's well.
1) remove the valve stem Schrader valve
2) put the clamp over the tire at about a 15 or so degree angle (to the axle) so that one jaw firmly grabs the wheel rim and the other jaw just misses the wheel and pushes only on the tire bead. Make sure the position of the clamp is at least 90 degrees away from the tire valve stem so there is no risk of damaging the sensor.
3) compress the clamp as far as it will go- this was not far enough to actually break the bead but it did leave a gap between the tire wall and the wheel rim; at this point, use the tire irons alternately above and below the clamp to further push the tire away from the rim. As the tire is forced toward the center of the wheel with the iron, take up any slack with the clamp. Pretty soon the bead will be clear of the rim; at this point just move the tire away from the wheel enough to jam a piece of wood in the gap and then release the clamp. Rotate the wheel 90 degrees, further away from the valve stem, again use the clamp and if needed a tire iron to open a gap between the tire and the wheel and stick another piece of wood in the gap. Do this in three places about 90 degrees apart and finally rotate the tire so that the valve stem (where there are no wood blocks) is facing the back of the bike.
4) Again position the clamp around the tire / wheel and begin to move the tire sidewall toward the middle of the wheel. It will move easily now that the bead is fully broken; you only need to basically squeeze the sidewall of the tire. Be careful as the tire bead approaches the center as it will move right across the TPS sensor and may actually touch it. If it does touch it, slip a tire iron between the wheel center and the tire bead to gently lift it away from the sensor and keep squeezing the clamp; the tire bead will move to the far side of the sensor.
5) The sensor will be fully exposed at this point (easy boys!) so just reach in with a hex wrench, remove the valve stem body (from the inside) and take out the sensor.
These are the clamps I use:
Bead broken on one side only:
On the far side, catch the wheel edge so as not to break that bead:
Put blocks in to hold the bead away from the rim as you go
This is what it looked like when everything was in position to get to the sensor: Be careful because just pushing the tire sideways WILL hit the sensor and break it if pushed hard enough: a tire iron is needed to coax the tire bead over the sensor.
Once the tire bead is pushed over and past the sensor, it is easy to remove it.
When finished, just remove the clamp (being careful to allow the tire bead to slide over the sensor without damaging it), then remove all the wooden blocks, apply some bead lube to the entire tire bead and inflate the tire to re- seat the bead. Install the valve stem valve, inflate the tire to the pressure you want and the bike is ready to go- no need to re- balance anything as the tire / wheel did not move (the far bead was not broken).
I think the whole thing would go faster and easier with two clamps but we did not have access to another one large enough. But using two clamps, I think the tire irons would not be needed at all and the whole thing would go considerably faster. I will give this a try if I get a chance before Tech. day.
Brian