Radial Tires and Tubes

[Steve Rinaldo]

I am about to put new tires on 1937-60. The Diamondback Radial site states that you shouldn't use tubes unless you have to. Has any anyone used new tires without tubes successfully or did you  have to use tubes. I would rather not use them if not needed. Steve

[The Tassie Devil(le)]

The trouble with using tubes with tubeless tyres is that the tubeless tyres have a tube material vulcanised inside them.

This layer, and having a tube inside as well can create a problem where the tube lining, and the actual tube rub together, creating a possible friction point, and this friction has been known to destroy the tube.

Now, as the tube has a loose-fitting valve protruding from the rim, instead of a tubeless tight-fitting valve, the air will leak out when the tube develops a porous surface.   And therefore a flat tyre.

Bruce.

[Paul Phillips]

I mounted Diamondback radials w/o tubes on my 41's original wheels a few months ago and have experienced no issues.  Not sure if there are nuance differences for your car, but seems like Diamondback's advice was good.

Paul

[Bill Ingler #7799]

I have run Diamond Back Radials without tubes on both my 41 and 47. Many CCCA tour miles on both cars with no problems from the Diamond Backs.  Bill

[Steve Passmore]

Problem on the older wheels is always going to be the valve hole. This is not made for a tubeless valve.  I have diamond backs on my 41 WITH tubes and have no issues whatsoever.

[pcb50]

Agree with Steve. To get stems to fit the holes on my '46 wheels the shop put on larger ones, probably for trucks, that caused the repro sombrero caps to be held off at the stems. That caused the wheel covers to wobble, although slightly. Tubes would solve that for me, unless there are now stems that fit the holes that aren't so wide at their base. Glad I looked at the forum today. Paul.

[Matt Harwood]

What size radials are you guys running on your '41s? My 60S needs new tires and I'm inclined to go with radials, but I'm not sure what size would look right.

Thanks!

[Steve Rinaldo]

Just a follow up. I talked to the tire expert for AACA and he stated that the way to tell if you need tubes is to see if the 2 halves of the rim are welded. If they are you shouldn't need tubes but make sure the bead setting area is not misshapen and clean. 

[Paul Phillips]

To the size question - I am using the Diamondback based on a 700R15 - see page 17 of their catalog.  I would recommend the beauty bar option as well.  Below is a picture from the GN show field that shows the tires fairly well.  Remember these tires are 1 point deduct each in CLC judging under the current rules.  If you drive your car, I think it is worth it to have radials over the bias plies.

Paul

[Classic]

Steve, you might check your wheels.  If your wheels have the center section (spider) riveted to the rim, every rivet is a potential leak point.  Slathering silicone sealant on each rivet can fix those potential leak points.  If your spiders are welded, no problem.

[Bill Ingler #7799]

Steve:  Here is a picture of my car using the 700x15 Radials from Diamondback. Great tires and I would also recommend adding the beauty bar to the tire.   Bill

[G Pennington]

My recently acquired '41 6267D has Coker 700x15 bias-ply tires.  Two of the tires are 16 years old and need to be replaced.  Was thinking about replacing all 4 with radials as this is primarily a driver and not a concurs car.  On the advice of others on this forum, I ordered a catalogue from Diamondback with the intent of buying a set of radials.  Was surprised that the 700R15 (Yokohoma) was not listed.  Contacted Rich at DB and he said he could still get them, but that they were actually an 8-ply trailer tire.  He assured me they would ride much better than the bias-plys, but if I was REALLY concerned about ride quality, I could order the 235-75R15 "DB II" tires.  Problem is, the tread on the 235-75R15's is 1.3" wider than the 700R15's (assume overall width is larger by a similar amount), and I am concerned about clearance, the way the car will look, and also the steering effort.
Any advise?  Also, what width WWs are you guys using?

[Roger Zimmermann]

I talked to the tire expert for AACA and he stated that the way to tell if you need tubes is to see if the 2 halves of the rim are welded.

Strange...On the '56 Cadillacs, the rim is riveted to the center part. Tubeless tires were standard on these cars.

[Steve Passmore]

tire.  He assured me they would ride much better than the bias-plys, but if I was REALLY concerned about ride quality, I could order the 235-75R15 "DB II" tires.  Problem is, the tread on the 235-75R15's is 1.3" wider than the 700R15's (assume overall width is larger by a similar amount), and I am concerned about clearance, the way the car will look, and also the steering effort.
Any advise?  Also, what width WWs are you guys using?

Running their 235-15 tyres on my 41 coupe without any clearance problems.