CST tubes

[Bobsiii]

I have a Magnum Metro, recently had a front tire flat. Tried to replace my patched tube and could not find a replacement with stem that fits fully thru the hole on wheel. Original is a CST 26x1.9/2.125 and they are out of stock everywhere I looked on stateside stores. I took the wheel to eBikesUSA in Denver to replace the tube and this is what they did.


My bad for not checking the job before I left the store. (I ended up with the same bad job when I tried to replace it myself, hoped bike shop would do it right. BTW eBikesUSA is about to become a Magnum dealer!)

I think having that much of stem shoved into the inflated tube is just asking for another flat, esp since most of my riding involves poorly maintained paths with deep seams in asphalt pavement and road crossings with 2" concrete curbs on crossing gutters.

Am I worrying excessively about another flat?
Are there other brands available in States that have same stem size?
Do I just have to go backorder from a retailer?
Or do I have to get wheel drilled out and use readily available tubes?

 

[MikeDD]

I would it drill myself or go tubeless if your wheels allow.

 

[Nova Haibike]

You want a tube with a 48mm (Schrader) valve stem.

 

[Sierratim]

Bikes in this price range are often equipped with double walled wheel rims for the extra strength they offer. The manufacturer's web site doesn't specify the wheels, but they appear from the photos to be deep enough to be double walled (a good thing). As @Nova Haibike pointed out, a longer valve stem will provide 'normal' valve extension beyond these rims.

I don't believe you're at risk of a flat from this install. The stem isn't "shoved into the inflated tube", it's simply extending through the double walled rim. If you can attach a tire pump normally, you're good to go. If not, get longer stem tubes.

There's no reason to drill out your rims. The existing holes in the rims are drilled for the larger Schrader valves. An even larger hole can weaken the rim.

BTW - You can use tubes with Presta vales with your rims. Just be sure to purchase tubes with threaded valve stems and install the provided lock ring collars to keep the stems centered in the larger rim holes. These smaller diameter valves are readily available in different length valve stems.