Questions about TPMS and valve stems/adapters.

[Berean]

With all the problems after market wheels are having and the proposed solutions to keep the inside stems from rubbing the brake line and control arms, I'm still not sure I understand everything.

Here's my questions:

1. Why do the aftermarket wheels have the second inside stem anyway? Can't the TPMS be attached to the outside stem?

2. Many of the adapters don't work on the inside lip of the wheel. Why can't the adapter be installed on the outside hole and used there? Then put a short rubber stem on the inside?

Thanks,

[Nine Ball]

1. Most wheel manufactures tend to place the valvestem hole where it is less likely to affect the appearance of the wheel. Some wheels have the valvestem protrude through the face of the wheel, taking the place of a rivet. Most wheels have the valvestem hole behind the face somewhere, usually on the drop-center of the wheel (the hump). TPMS sensors attach in various ways, they cannot always fit properly on that valvestem hole location. This is why adapters are required.

2. The TPMS sensor must lay flat, whether that is within the drop-center or on the hoop surface. This way, if you have a flat tire it won't get damaged. The sensor body itself must always remain below the outer edge of the wheel, never sticking out past the outer edge of the wheel diameter. Various pics attached.

The main reason is that there are only a handful of actual hoop makers that supply all of the wheel companies. These hoops are not built with TPMS fitment in mind, as thousands of cars do not have TPMS sensors. Therefore, the need for adapters exists. Also, TPMS sensors come in a variety of sizes, angles, mounting methods, so wheel makers cannot plan for each of them. Most of the time, the second hole is just for an adapter, the other one used for air. Whenever possible, yes it is best to try and get the valvestem hole provided to work, but that just isn't always the case. Every brand of wheel has their own hole locations, it is not a standardized industry. You are more likely get at TPMS to fit like OEM if you go with a stepped lip or cast aluminum wheel, as these tend to have the drop-center (hump) towards the front of the wheel much like an OEM wheel does.

Tony

[flht99b]

Tony, what kind of TPMS mounting does the Pro Wheels "Boost" utilize ?? Does the Boost end up having a 2nd valve stem pointing out the back of the wheel ??

[caverman]

Originally Posted by Nine Ball

1. Most wheel manufactures tend to place the valvestem hole where it is less likely to affect the appearance of the wheel. Some wheels have the valvestem protrude through the face of the wheel, taking the place of a rivet. Most wheels have the valvestem hole behind the face somewhere, usually on the drop-center of the wheel (the hump). TPMS sensors attach in various ways, they cannot always fit properly on that valvestem hole location. This is why adapters are required.

2. The TPMS sensor must lay flat, whether that is within the drop-center or on the hoop surface. This way, if you have a flat tire it won't get damaged. The sensor body itself must always remain below the outer edge of the wheel, never sticking out past the outer edge of the wheel diameter. Various pics attached.

The main reason is that there are only a handful of actual hoop makers that supply all of the wheel companies. These hoops are not built with TPMS fitment in mind, as thousands of cars do not have TPMS sensors. Therefore, the need for adapters exists. Also, TPMS sensors come in a variety of sizes, angles, mounting methods, so wheel makers cannot plan for each of them. Most of the time, the second hole is just for an adapter, the other one used for air. Whenever possible, yes it is best to try and get the valvestem hole provided to work, but that just isn't always the case. Every brand of wheel has their own hole locations, it is not a standardized industry. You are more likely get at TPMS to fit like OEM if you go with a stepped lip or cast aluminum wheel, as these tend to have the drop-center (hump) towards the front of the wheel much like an OEM wheel does.

Tony

Nice.....thanks for posting these pics. I'm new with all the TPMS stuff and it's nice to actually see what they look like and how they fit on the wheel.

[Nine Ball]

Originally Posted by flht99b

Tony, what kind of TPMS mounting does the Pro Wheels "Boost" utilize ?? Does the Boost end up having a 2nd valve stem pointing out the back of the wheel ??

Pro Wheels typically have one hole, located behind the face on the drop-center, but aimed towards the front of the wheel. We've used aftermarket sensors directly in that hole no problem. Brands vary on hole locations, but it doesn't really matter as long as you have the proper adapters that work. The goal is to get the sensors inside the tire, and not have them stick out past the wheel diameter. Too bad the OEM sensors have such long stems, they were probably intended for SUV's.

[Berean]

Thanks. I'm going to try and use adapters/TPMS on the outside hole, and use short rubber stems, or mount them upside down, on the inside hole.

[Nine Ball]

Berean, if you want to play safe, mount the sensors however it works, then bolt the wheel onto the car - before mounting the tire. Make sure it rotates freely without hitting anything. Also be sure the jack is under the suspension, so that the suspension is in the normal position and not hanging down. For front wheels, be sure to turn the steering wheel completely in both directions to check for clearance too.

If everything clears, you are good to go.

[Berean]

Wouldn't it work just to put the stock stems/TPMS in the outside hole? You could get a chrome sleeve and cap. It would be kind of long but it might be better than an adapter.

[Nine Ball]

Every single wheel brand has different hole locations. You can't just make a blanket statement about putting a sensor in the outside hole. Not every wheel has two different holes. Sometimes you even have to drill your own hole (rare) for TPMS fitment. Just about every forged wheel has the hole on the inside of the wheel, not the outer face. Like I said, only stepped lip wheels have the outer hole on the face.

Yes, it is always preferred to try and make the TPMS sensor work without an adapter, but that is not always possible. Sometimes that valvestem collides with the brake caliper, or the suspension arms, or the brake lines. The smaller the diameter of the wheel is, the bigger the possibility of clearance issues. Larger wheels move the stem/sensor further away from the typical collision areas. Lowering a car can also increase potential of clearance issues, due to it changing the geometry/location of the suspension components relative to the wheel.

And then there are those pesky "Roller Skate" weighted brake pads on the later 2010 Camaro builds. Luckily those can be removed by simply changing out the brake pads to an aftermarket brand. Those roller skates are realllllly dumb.

[Nine Ball]

Examples.

Here is a "Stepped Lip" wheel. On these wheels, the drop-center area (the "hump" on the hoops) is toward the front of the wheel. Notice it has the valvestem much like an OEM wheel would be, on the outer lip.



On a smooth lip (aka "soft lip", or "reverse-drop") wheel, it provides a more modern appearance at the sacrifice of moving the drop-center to the rear side of the wheel. This allows the wheel maker to use a larger diameter center on the wheel, making a wheel visually larger looking. Most forged wheels are built similar to this. The valve stem is then located within the middle of the wheel. It just looks better like this.



And then you have some smooth lip wheels that pass a 90-degree elbow type valvestem through the face of the wheel. You definitely need TPMS adapters for this type of valvestem, show above on my first reply. The one with the 90-degree elbow.

[Berean]

I have Foose Legends. The outer valve stem is right between the spokes on the flat chrome surface. The inner TPMS stem is at an angle on the back lip.

It seems like either the adapter or the direct TPMS valve stem solution would work with mine. I'll plug the back hole with a reverse stem.

[will69camaro]

Those bottom wheels are SICK!

[Nine Ball]

A couple more different adapters. Quite a few of them out there.

[flht99b]

Tony, exactly what parts do I need to install factory TPMS sensors in the Pro Wheels Boost wheels ?? I bought the wheels and tires from Roger. I'm having the same issue most others are having with the aftermarket sensors. They learn fine using the owners manual tire pressure learn sequence but then drop out within about 20 miles giving the "service the tire monitoring system" error.
Ed M.