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-   -   Tube Advice: ARAYA 20 x 1.50 Rims (http://www.bikeforums.net/folding-bikes/850912-tube-advice-araya-20-x-1-50-rims.html)

DaveInJapan 10-06-12 09:08 PM

Tube Advice: ARAYA 20 x 1.50 Rims
 
1 Attachment(s)
Hi. I'm in Japan, and I have a 13-year old Bridgestone Grandtech folding bike. The rear tire won't hold air, so I intend to replace the inner tube. The rims are marked ARAYA 20 x 1.5 GP-710, and the tires say Bridgestone iRC 20 x 1.75. I'll attach a photo showing the valve stem. I'm new to this, and I need advice. I just read that there are different types of valve stems. What type of inner tube should I buy so it fits the rims and valve hole? I plan to order online, so exact specs would be a great help. Thanks.
http://bikeforums.net/attachment.php...hmentid=277045

bargainguy 10-07-12 07:32 AM

Dave, from the photo, looks like a Presta valve tube with a threaded Schrader adapter. If you unscrew the little adaptor atop the valve, it will probably reveal a Presta valve. Some folks leave the adapter on all the time in case they get stuck somewhere without a pump, as it will allow you to fill the tube from a gas station pump.

Presta valves have a small screw nubbin which needs to be unscrewed to the open position before you can get air in or out of the tube. Schrader valves are the typical auto tire valve, no unthreading needed, and there is no nut holding the valve to the rim as with a Presta valve. Presta valve sections are metal, Schrader are rubber.

One word of caution - tubes and tires expressed in decimals are not equivalent to those expressed in fractions. Make sure to order the same size tube as before, so if yours is in decimals, order the appropriate decimal tube.

Don

sk0tt 10-07-12 08:01 PM

Looks like a Woods or Dunlop valve to me, you can replace it with a 20 x 1.75 tube with a Schrader valve.

badmother 10-08-12 12:41 AM

Quote:

Originally Posted by bargainguy (Post 14815018)
Dave, from the photo, looks like a Presta valve tube with a threaded Schrader adapter. If you unscrew the little adaptor atop the valve, it will probably reveal a Presta valve. Some folks leave the adapter on all the time in case they get stuck somewhere without a pump, as it will allow you to fill the tube from a gas station pump.

Presta valves have a small screw nubbin which needs to be unscrewed to the open position before you can get air in or out of the tube. Schrader valves are the typical auto tire valve, no unthreading needed, and there is no nut holding the valve to the rim as with a Presta valve. Presta valve sections are metal, Schrader are rubber.

One word of caution - tubes and tires expressed in decimals are not equivalent to those expressed in fractions. Make sure to order the same size tube as before, so if yours is in decimals, order the appropriate decimal tube.

Don

Wrong, no adoptor on this valve. Get rid of both tubes and buy new ones. sk0tt is right. I am haunted by these crappy valves where I live and refuse to use them on any of my bikes.

DaveInJapan 10-08-12 04:42 AM

Hi, and thanks! I just had a Canadian friend who is knowledgeable about bikes take a look, and he confirmed that it's a Dunlop/Woods, or what the Japanese call an 英式 (English style) valve. My friend replaced the valve rubber, and the tire holds air again for the time being. But he, too, suggested that I get new tubes with Schrader valves, or what the Japanese call 米式 ("American-style") valves. It looks to me as if a Schwalbe Tube AV7 with Schrader valve would work, and I can get them online here in Japan for 850 yen each. I appreciate the advice.


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