Re: Wheel damage from Presure Pro sensor Reply #25 – August 20, 2012, 05:13:00 pm Dave.... Thanks for the explanation. Like your setup. Perfect. Neal, thanks too. Love the calculation. 4. 5 lbs is not a lot considering the total weight of the dual tire assembly and the forces involved. But not having it there would be better.... I have to admit that. But the question for me is, if a PP sensor is OK on the wheel by itself, will adding about 25% (i.e., going from 3.4 to 4.5 lbs) more weight for the pad cause a big problem? Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #26 – August 20, 2012, 08:52:11 pm I don't think the concern is the additional forces placed by the sensor or pad on the entire wheel assembly. But it would be good to watch what the additional forces do to the stem. Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #27 – August 20, 2012, 11:10:01 pm Quote from: George Hatfield – August 20, 2012, 05:13:00 pm......................................But the question for me is, if a PP sensor is OK on the wheel by itself, will adding about 25% (i.e., going from 3.4 to 4.5 lbs) more weight for the pad cause a big problem?..............................................George,No. Adding less than 25% to the PP Sensor, particularly where you have located it (to prevent further marring of the wheel) and where the stem can only move a very small amount before movement is limited by the wheel, isn't going to create new forces that you need to be concerned with. I don't know how rugged your stem is, so, as Benji said, look at it closely for a while until you become confident with it.As common sense would tell you, the "fictitious" centrifugal force (it's a calculated force and not a measurable force) of the sensor at 60 MPH (4.5 lbf) is tiny in comparison to the 360 degree distributed centrifugal force of the wheel plus tire (integrated over 360 degrees, I would calculate our wheels plus tires to have on the order of 20,000 lbf or a 10 ton-force, distributed over 360 degrees, at 60 MPH). Also, the PP, being closer to the center of rotation, has proportionally less and less effect as MPH increases. As a side topic;This also leads to the logic of why the Centramatic type wheel balancers work so well. That wheel plus tire assembly that exerts 20,000 lbs of 360 degree centrifugal force at 60 MPH, only exerts 5 lbs of 360 degree centrifugal force at 10 MPH. It is possible to add physical weights that will balance any rotating unit at a given RPM, say at 60 MPH. But that same rotating unit will have somewhat different centrifugal forces at 50 MPH and 70 MPH, as compared to 60 MPH. Depending upon the nature of the imperfect weight distribution in a wheel plus tire combination (if it were perfect, one wouldn't need any artificial weights to balance the centrifugal forces), the Centramatics can show dramatic improvement over just physical weights . Within the Centramatics range of reactivity (a grossly imbalanced wheel/tire assembly would require some physical weights, but I have never seen that happen with Michelins) Centramatic technology allows the rotating assembly to continually and automatically adjust, over all rotational speeds, bringing perfect balance, not just at one speed but at all RPM.Just an aside, FWIW,Neal Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #28 – August 21, 2012, 06:02:47 am Neal and others.. thanks for all the information and comments. Much appreciated. Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #29 – August 24, 2012, 06:41:23 pm Update.... the plastic tubing covers/pads (see above) on the PP sensors have stayed on now for about 800 miles of highway travel in 90 degree plus weather. I can see no movement. I did report the wheel wear problem to Doug McMeen at Pressure Pro. Doug said he had not heard of this problem before and that the sensors are made of Xenoy plastic, which is a mix of plastics with one component being polycarbonate. Obviously, this plastic is very hard. Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #30 – January 03, 2013, 02:36:10 pm Another update to the Alcoa wheel damage caused by Pressure Pro sensors. I was able to contact someone at Alcoa and this is what he had to say. "Unfortunately you cannot repair that type of issue. As for the wheel it might eventually crack out of that area resulting in air pressure loss. Robert (Buddy) BazzelSr. Quality TechnicianAlcoa Wheel & Transportation Productsrobert.bazzel@alcoa.com"I plan to have the valve stem extensions replaced with a longer valve stem (similar to what Dave did) before we hit the road again. Happy New Year everyone!George Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #31 – January 04, 2013, 11:43:44 am Quote from: George Hatfield – August 18, 2012, 12:56:41 amNeal... What a great idea! Thanks. Wish I had paid attention last year!Just one question.... how do you put teflon tape on the valve stem? Probably not, right? So do you use anything else to ensure a good seal?GeorgeRegarding the use of Teflon tape. I just received the new O-ring seals for the Pressure Pro sending units. I have had a slow leak on one of my towed tires since I got the PP system two years ago. The new O-ring works great with no Teflon tape or anything. I'm not sure how long this O-ring seal system has been available but I think it will solve all of the leakage problems with pressure pro. The cost was $15.00 including application tool from PP. Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #32 – January 04, 2013, 04:49:47 pm Pressure Pro sensors do not seal on threads and Teflon tape will not improve air seal, but may make it easier to remove sensor. Be sure to not let any pieces of Teflon tape get into PP sensor. I do not believe in using Teflon tape with Pressure Pro.Pressure Pro sensors only seal against the top round surface of valve stem, so be sure it is smooth and even. New seals inside PP sensors will improve seal to top of valve stem.Teflon tape is only used for tapered threads, like pipe thread, aka National Pipe Thread, NPT, FNPT, MNPT. Bolts, flare, compression and valve stems are not tapered and do not normally benefit from using Teflon tape or Teflon sealer. Quote Selected
Re: Wheel damage from Presure Pro sensor Reply #33 – March 05, 2013, 03:14:38 pm Final update from me (hopefully). I removed the valve extensions from both inner wheels as Neal suggested. Also bought some tools to check the pressure without the extension and to add/remove a PP sensor, dill valve and valve cap when the PP sensor is off. The white tool that looks like a piece of PVC tubing is from Pressure Pro. It is made up of a piece of 3/4" schedule 40 tubing with a schedule 40 coupler on the end. The coupler fits tight on the PP sensor without modification. Total cost to make something like this must not be more than $0.50. PP should give these away... I won't say what I paid for it. But it does work. The top of the PP sensor is about 2.25" from the outer edge of the outside wheel. Close enough to make serving the tire easy. No more damage to the wheels from the inner tire sensor! Thanks Neal. Wish I had thought of this earlier.George Quote Selected
Topic: Wheel damage from Presure Pro sensor