26 November, 2012

Crankbrothers PowerPump alloy failure


I love things well done and I must say this pump was and still is a very well done thing, almost.. It's almost because like any thing human does it has it's flaws. But enough talking, lets get to the real stuff

We're talking here about the Crack Brothers Power Alloy Bicycle Pump, a metal alloy bicycle pump with two heads that fit shrader (auto) and presta valves, dual piston design for high volume or high pressure output and a pressure gauge that tops at 160psi/11bar end scale. It's also light at around 200g (case included) and small with about 24cm/9.5inches long.

Tried my own blow out view just to see how complex it really is and I must say I was impressed as it showed to be composed of quite of lot of bits and pieces. I must mention that it's not even blown all the way as there was more to be taken apart. The head assembly is the interesting part. Pressure comes through a center canal that is tapped by the pressure indicator. In the end there's another tap surrounded by a rubber gasket that slides between two red plastic adapters for the individual heads.

While most bike pumps do offer dual valve support by using a single output head with reversible end piece, the guys at Crank Brothers went their own path with this dual head design. Can't say I see any benefit from this as this adds volume, weight and complexity to what could have else been an even better product. To make it worse, this very own feature was the cause of the failure. You can also blame it on user error but when using presta valves it's no way telling how deep is deep enough when you connect the pump with the valve head. Since I used it quite a lot on presta valves, my smart little pump failed about a year after purchase. When opened it turned out that the end of the presta valve from the bike chew up a groove into the rubber gasket from the pump head chamber during twisting in and out the head to pressurize the connection between pump and valve. That gasket is what seals the transfer of pressure between then pump piston and the head assembly. As a quick fix and another year delay I mounted the gasket upside down. Then it failed again and it was time to search for another gasket and sadly the manufacturer doesn't provide any spare parts for this pump. After a lot of search I finally improvised something but the material was softer and it didn't last long till it failed again.

Looking back at all this trouble I guess I could have taken the time to do some trials with mounting the pump on a presta valve without touching the gasket but it's not that easy to apply when you're on the run in a trip or you lend the pump to a friend. Funny thing is that on the product cardboard it stated "warranty: lifetime" :) not that I can benefit of it here in Romania where the reseller only covers 1 year warranty long gone. I still love my pump and hope to find again somewhere another replacement for that darn gasket but in the meantime I had to buy a second pump.

I chose a POINT GM-61 that's quite long, heavy and cumbersome but promises to be more reliable, hope the hose won't be a failure cause ;))

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