MTFCA Forum

I just ran across this in the service bulletins...

Hope you're not confusing this with the aftermarket flaps that some use inside the tire...

Read it again

Correct. Ford installed rubber fabric tire flaps in all the 21" balloon tires used on split rims. You have to protect the tube from the seam of the split rims.

Ford notice in the Service Bulletin to let mechanics know that a tire flap in the wire wheel, with its drop center, can block the tire bead from squeezing into the drop channel, making install or removal most difficult.

The wire wheel should use just a narrow rubber rim strip, that lays into only the drop channel to protect the tube from any imperfections of the spoke welds there.

Drop center rims use a rim liner

Dan, I think what Adam found is that the rim flap used in the clincher tire cannot be used in the wire wheels, and must be replaced with the correct rim flap.

...thus indicating that there were flaps installed in clincher tires, at least in the '20's...I've seen this before, but decided not to post it, lest I suffer the slings and arrows of experts telling me that I and documentation were both wrong. I'm glad Adam posted this.

That Service Bulletin is dated January 1927 and the ‘wood wheel equipment’ infers equipment as straight side split rims used with balloon tires on wood wheels at that time. Ford used these wide flaps for balloon tires and didn’t in clincher tires. Aftermarket narrower flaps could be had for clincher tires.

Wide flaps for split rims are required as the split can cause tube problems. Conversely wide flaps used in drop center rim of wire wheels make mounting and removal of tires very much difficult.

No need to read it again- flaps were not used in clinchers...

So even though it is stated in a Ford Service Bulletin that flaps are used there are those who know more and still maintain flaps were not used. And we wonder why the world we live in is such a jacked up mess......

For what its worth, here are my experiences of not using rim flaps and using rim flaps on 30 x 3 1/2 clincher tires...…

When I built my 1922 huckster as a teenager in the 1980's, I started out with old cotton cord tires that I purchased as I found them at swap meets, flea markets, etc. They still had some life left in them, and I mounted them on my rims without flaps. However, the insides of those old cotton cord tires were nice and smooth inside, and the insides of the beads were smooth, just the texture of the cotton fabric. I had relatively few flat tires with those tires.

After a few years, I wanted to go on the 1991 MTFCA "Tour of the Plains" in Great Bend, Kansas. I ordered new Firestone 30 x 3 1/2 Ex-size, Gum-dipped, made in New Zealand, tires for my Model T. I took the old cotton cord tires off the rims and mounted the new tires, without flaps. I hauled my Model T to Great Bend, and began the tour. In the first two days I had at least seven flat tires, and yes, my tires were aired up to 65 psi. With temperatures in the 90's and driving 100 plus miles per day, those tires flex, and the insides of those new Firestones and the bead area are full of mold marks and irregularities that wear on that inner tube. When I pulled them apart daily to patch the tubes, the wear and chafing of the tubes was very pronounced in the area where the tube would squeeze into the gap between the beads.

Steve Coniff, Larry Ranard, Howard Genrich, and others educated me about the use of flaps on that tour. Since I didn't have any at the time, they lent me spare tires mounted on 30 x 3 1/2 demountable rims, and I finished the last few days of the tour trouble-free. After ordering flaps and installing them after I returned home from the tour, I do not remember having another flat tire on my Model T again.

Maybe some of the reproduction tires are smooth inside and between the beads and do not require flaps to be successful. All I know is that the Firestone tires I used were not successful unless flaps were used. Whether Ford used flaps on clincher rims or not is irrelevant. The new tires today are not the same cotton cord tires that were used in the 1920's and 30's. Think about it. The flap prevents the tube from squeezing into that gap between the beads . That is where all of my leaks began, until the tire would lose pressure and shift on the rim, cutting off the valve stem in some cases.

Robert, the service bulletin does indeed refer to Ford's use of flaps. However, the bulletin refers to BALLOON tyres, wire wheels and previous wood wheels. Therein lies the the answer. It refers to 21" wheels used on the 26-7 imporved cars, and the difficulties created if the wrong components are mixed. As others have pointed out, the drop centre wire wheels need a narrow rim liner to cover any roughness in the welds of the spokes in the well of the rim. Previously the balloon tyres used on 26 model 21"wooden wheels required a wider flap to protect the tube from the join in the split rim. This is the previous use of flaps referred too. Ford did not use flaps on 30" clincher rims.

That is not to say that some find using flaps in 30"clincher tyres beneficial.

Allan from down under.

Yes,maybe,and none of the above.What is true today is that you are paying your own cost if you use them or not? Have any of the old timers that remember truck tires with tubes on non drop center rims remember seeing one mounted without a flap? Bud.

Bud, there is a different reason for using flaps in non-drop centre rims on trucks,including TT's on the rear. Such rims need a lockring to be fitted to form the second side of the rim once the tyre/tube/flap assembly is dropped over the rim. Some have two , one to form the outer rim edge and a second to hold it in place. Both necessarily have open joins as well as the open interface between these components. All of this means water can get into the assembly, and rust is a major problem. It is this rusting which nescessitates the use of flaps to protect the tube from damage. None of this applies to clincher rims/tyre fitment, especially today with rubber stem tubes. With the old metal stems water could get into the rim at the valve stem hole, but even this was minor unless the car was driven in deep water.

Allan from down under

Allen Long ago when i was a young man i usually worked two jobs at the same time.For a couple of years part time i worked for a Goodyear tire store changing truck tires and i have never seen the water/rust in a tire as you speak of. Flaps were used to keep the tubes from getting under the bead of the tire!!! Bud.

Just for discussion sake, I have 21 inch split rims and don't run flaps, I make sure the rims are smooth on the inside. I have never had a flat tire. I also have some old Riverside Tires, (from the 1930's), on my car when I bought it and they did not have flaps and the tubes still held air pressure.