OT (sort of) 30x3 1/2 inner tubes and stems....

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2018: OT (sort of) 30x3 1/2 inner tubes and stems....
Top of pagePrevious messageNext messageBottom of page Link to this message  By j case on Thursday, October 25, 2018 - 08:25 pm:

Greetings!

A few days ago I bought a 30x3 1/2" Stanweld/Jaxon style clincher rim, either to make a spare, or possibly replace one of the rims on my 1913 Studebaker (it currently has incorrect rims on the rear). Once I bought the rim, I intended to order a fifth matching Wards Riverside tire from Lucas, and everything necessary to mount it. Simple, right?

The car has Stanweld wood felloe demountable rims. These rims existed on Fords too, but as far as I know, only as an aftermarket accessory, never as factory equipment. They are 30x 3 1/2" both front and rear.

For the last few days, I have been reading every old thread I can find about 30x3 1/2" tires, tubes, and flaps. I see there is no consensus about flaps. Since my car doesn't currently have flaps in it's tires, and since according to all the old threads I read Ford did not use flaps in production, I decided to go without. I have on the shelf a spare rubber-stem tube I bought a year or two ago from Snyder's, and I figured if I pinched a tube while mounting, i would have the extra Snyder's tube for a second try.

In all my reading about flaps, I kept stumbling across threads about problems with stems. Leaks, stems the wrong size, etc. Normally I would default to rubber stems, as my car is not a showcar, and I would expect the valve housing to be well vulcanized to the rubber. I found several threads about the rubber stems being too big (3/4"?!!) to go through the holes in the rim, and also trouble with leakage between the rubber and the stem.... Drat! I guess it will have to be the more expensive brass stems then, but at least it will look more authentic. Then I read in multiple threads that the brass stems in new tubes are also the wrong size!

Well, I guess I will get back to the brass stem subject in a moment, but first I have a some questions about currently available rubber stem tubes (in October 2018), as many of the threads I have been reading were old, some of them by 10 or more years.

The holes in my rims are very slightly over 1/2" inch. The butt end of a 1/2 inch drill has a little clearance, but not much. My Snyder's tube from a year ago is 5/8". I'm not sure if it will squeeze in. Maybe.

1) How big are the stems on the currently available RUBBER stem tubes? Are they any closer to the right size than they were??

2) How big is the stem hole in a real Model T demountable rim?

3) Will the current rubber stems fit a Model T demountable rim or is it just the non-demountable rims that have trouble?

I found this thread where "Hartford" tubes sold by "Bob" were mentioned, http://www.mtfca.com/discus/messages/822076/837555.html?1518726842

4) Who is Bob, and where is he selling these Hartford tubes? Do the rubber stems fit any better than the others?

In thread after thread after thread, it seems many people around here prefer the metal stems. After reading about all the trouble with rubber stems, I figured I would just get metal stems, and all the hardware, and do a period-correct job. Apparently, however, all the brass stem tubes come with a Schrader 725 style stem, instead of the 777 a Model T would have used, and that it is also too big.

I think I can probably make one of those work, but I have more questions.

5) OK, so the 725 is too big. Has anything changed? Is anyone making tubes with the 777 yet?

At 1/2" the 725 will fit through the holes in my rims without drilling. I would need a bridge washer and nut for the 725. The parts houses are all showing a "felloe nut" and a dust cover also.

6) Where does the felloe nut go on a Model T with demountable rims? does it screw down against the rim? or does it have to screw down to the felloe after the tire and rim assembly is changed?

7) It looks as though when using the 725 that the dust cover screws directly to the stem, rather than to the felloe nut. I even saw an old Schrader diagram like that. The reproduction brass dust covers look to have the threads at the very bottom. Does this really mean you would have to screw the dust cover over an inch or more of fine threads just to check the air? It sounds crazy. Am I missing something?

I am at a loss for what to order now. Thank you for anything you can add.

John


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Friday, October 26, 2018 - 07:28 am:

"Bob" is probably Bob Bergstadt. Here is a link to his profile:

http://www.mtfca.com/cgi-bin/discus/board-profile.cgi?action=view_profile&profile=fatman-users

The metal stem tubes from the vendors still use the too-large Schrader 725 size stems. The dust cover screws onto the rim nut (called a rim washer in the picture). Here is a picture of the arrangement of the parts on the wheel:


/pic



As far as I know, the only way to get tubes with Schrader 777 stems is to collect the parts and make your own:

http://www.sheepisland.com/cars/tech/metal_stems


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Friday, October 26, 2018 - 11:35 am:

I think I can answer a few of the questions.

1 The rubber stem on a current TR-135 tube is .575" at the base.

2 The hole in a Hayes demountable rim I checked is .635". I don't know about Firestone, Kelsey, etc.

3 I have used rubber stems in both kinds of rims & wheels.

4 http://bobsantiqueautoparts.com/

5 The 725 is bigger than the stems Ford used, but it's the size used on the current metal stem tubes and fits my wheels with no trouble. I use the 725 stems on my 1915 because I have the reproduction brass dust covers which fit. On my 1923 with demountables I found original dust covers to fit the 725 stems.

6 Mark's diagram shows how the parts go. I'm not sure what the "felloe nut" is. The Lang's catalogue shows the "rim washer", as in the diagram, which is actually a nut.

7 Yes. It takes a lot of turning, but in the great scheme of the Universe it's not a big deal.


Modern metal stem tube (725 size) with original rim washer and dust cover.


725 stem with reproduction washer and cover.


Stems I bought at Hershey a couple of weeks ago. As you can see, the larger size is most common, and that's what I use. Only three of these are Model T size.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Friday, October 26, 2018 - 12:07 pm:

I just found a Hartford tube. The rubber stem measures .6".


Top of pagePrevious messageNext messageBottom of page Link to this message  By j case on Friday, October 26, 2018 - 09:01 pm:

Thank you Mark and Steve! That is a huge help.

The only thing I am unclear on is the location of the rim washer (what I was calling a felloe nut) when used with a demountable rim.

Steve, If that is your 1923 with demountable rims in the first picture, then it answers the question. The rim washer is out where you can see it, on top of the felloe, and you have to remove it before changing a rim. Is that right?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Friday, October 26, 2018 - 10:07 pm:

Yep, you got it.


Add a Message


This is a private posting area. Only registered users and moderators may post messages here.
Username:  
Password:

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration