Can I Fit Tubeless Tires to Factory Cast Wheels?

[dilligaf]

mtiberio wrote:  Yes, but at speed, centrifugal force is keeping the tank valve in....   8^))

Sir, you got me.  I  have a high school education and I graduated very near the bottom of my class.  :BEER:
Matt

[Guido Valvole]

The original poster asked about the Harper's valves. I just went tubeless with them last week, Avon Roadriders on a V50 Monza. There is a rubber (maybe neoprene) seal on the inside that forms to the very curved center section of the skinny smallblock wheels just fine. I noticed a little pressure loss, more likely because it was 70º when the tires were mounted and 45º Saturday morning. Same amount of pressure decrease in the V50, which has the same tires with tubes.

They work. Roadrider front gloms into rain grooves almost as badly as a Metzler Lasertec but there aren't many other choices for skinny old alloy rims.
cr

[charlie b]

cr,  if they have the right size try Sport Demons.  I also have few choices with my 16" rims.

[Wayne Orwig]

Bearing in mind the concave shape of the internal surface of the Guzzi wheel,
does the rubber seal sit nicely in place without the nuts being done up excessively tight?

Some of them, like the one in the photo above, seal on the OUTER surface of the rim.

[charlie b]

The stem thingy's I have use rubber washers on the inside and outside.

[Stevex]

Some of them, like the one in the photo above, seal on the OUTER surface of the rim.

But I'm not talking about the one in the photo, If you'd quoted my upper two lines you'd see I was talking about the Harper's item in which the seal is on the INNER surface of the rim.
However, I am considering making up a spacer that fits the concave inner rim surface and provides a flat surface for the nut, so I can indeed fit the racing valve stem in the photo  ;D

[Guzzi_Don]

The original poster asked about the Harper's valves. I just went tubeless with them last week, Avon Roadriders on a V50 Monza. There is a rubber (maybe neoprene) seal on the inside that forms to the very curved center section of the skinny smallblock wheels just fine. I noticed a little pressure loss, more likely because it was 70º when the tires were mounted and 45º Saturday morning. Same amount of pressure decrease in the V50, which has the same tires with tubes.

They work. Roadrider front gloms into rain grooves almost as badly as a Metzler Lasertec but there aren't many other choices for skinny old alloy rims.
cr

Thanks CR for the detailed description of your conversion. I will email Harper's as I doubt these valves are available here in Australia.

[Guzzi_Don]

cr,  if they have the right size try Sport Demons.  I also have few choices with my 16" rims.

Charlie thanks for the recommendation on the Sport Demons as this is the other half of the job to be done after the valves are replaced.

Sport Demons are tubeless?

[dilligaf]

I believe the Guzzi part number for 8.3mm tubeless valve stems for my 87 Le Mans is 28617760.  Why not give Pete a call?   :BEER:
Matt

[Curtis Harper]

Can someone from Harpers contribute to this thread and verify that the valve they are advertising will fit and do the job?

Yes these stems will work in the Guzzi wheel. Have been using them for years without issue. the rubber will conform to the concave part of the rim and seal fine. 

[dilligaf]

Well there you go.  Simple and safe.  ;-T  :BEER:
Matt

[Greg Field]

Yes these stems will work in the Guzzi wheel. Have been using them for years without issue. the rubber will conform to the concave part of the rim and seal fine.  

What Curtis says is true, but be careful to not over-torque the nut on the i.d. of the wheel's rim, or it can crack the shoulder on the valve's stem, and then it will leak. Ask me how I learned this . . .

[charlie b]

Charlie thanks for the recommendation on the Sport Demons as this is the other half of the job to be done after the valves are replaced.

Sport Demons are tubeless?

Yes, they are.  I use a Sport Demon on the front and cheap Shinko's on the back (the rear Sport Demon only went about 6k miles, the front went well over 10k).

[Chuck in Indiana]

Yes, they are.  I use a Sport Demon on the front and cheap Shinko's on the back (the rear Sport Demon only went about 6k miles, the front went well over 10k).

This is what I've been using on the Lario to good effect.

[Guzzi_Don]

Thanks Curtis,

MUCH Appreciated

[Guzzi_Don]

What Curtis says is true, but be careful to not over-torque the nut on the i.d. of the wheel's rim, or it can crack the shoulder on the valve's stem, and then it will leak. Ask me how I learned this . . .

AND . . . Thanks Greg for that valuable information.

[Kiwi_Roy]

FWIW I have been running tubeless on my California II for several years, I used regular tubeless stems, I had to file a flat on the inside and outside to take the seals. Tank valves are probably a better way to go.
I'm also running tubeless on my 72 Eldorado and that has spokes. I have had a bit of trouble with these leaking around the spoke nipples but they have never gone down as fast as a tube puncture can and never left me stranded.