28 November, 2012

Bicycle Handlebar Mount Holder review

Taking the time to talk again a little bit about the cheap little things one can find over ebay. Got this gizmo for 5$ with free shipping from China all the way to Europe.

It states to be a clamp for bike handlebar mounting of a photo digital camera but I'd  think more at something like a lightweight GoPro, ContourROAM or these type of action camers. Anyway, my real interest for this thing was as a studio clamp for holding flashes or other accessories.

Bicycle Handlebar Mount Holder, closed view

Bicycle Handlebar Mount Holder, opened view

The clamp has a standard camera screw of 1/4-20 BSW so it can theoretically connect to anything that's light enough. The construction is not as bad as I expected it to be in this price range. Of course it's mostly plastic but good enough to get the job done.

The jaws are padded with rubber for extra grip and can open wide enough to clamp even on my Giottos MT8350 center column. You have a screw with which you set your opening and then a lever that grips the jaws on the support. Once fixed into position you now have 2 axes of control for your "payload". One is for tilting done with a screw while the other is for rotation through a rather ingenious spring loaded teethed coupling between the actual clamp and the mounting plate. The spring is quite strong and great for impressive static loads but can't deal with any bumps and vibrations given by any bike riding on anything but ideal tracks. The mounting plate has a metal screw with a nut that helps to further lock the payload. The nut is also doubled with a rubber washer for extra grip.

As I've said, I've done some testing on my Giottos MT8350 as a support and a Canon 580EX II as a payload. It's doable without much effort even horizontally with the flash extended but it's obvious the mounting plate junction is under excessive effort for it's capability.

Bicycle Handlebar Mount Holder fixed on a tripod holding a Canon 580EX II Flash in horizontal position

In the end, it's 5$ that weren't spent for nothing, I have a clamp that works if taken to appropriate use but it must not be mistaken with the whole different world of metal clamps like the ones from Manfrotto or even the way cheaper CoolLCD's Super Clamps.

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 ;))

10 November, 2012

Mini Dynamo Hand Crank USB Emergency Charger review

OK, I admit it, I was geek enough to order one of these gizmos from ebay. It was only 1$ so no harm done, right? Well.. rolled myself laughing when I saw the same thing for 20$ (twice reduced, from 49.99 and then 25) on amazon here. Luckily there's also another version here  for only 3.59$ :)) There are things about economy I just can't figure out.

But back to our little toy, if you haven't figure it out yet, let me explain it to you. It's a small crank driven dynamo that generates just enough juice to power an USB charging device like a cell phone, mp3 player or any other small type electronic, don't dream about tablets or other power hungry beasts. The key phrase there was "just enough" because it won't get to 100% but a charge or even a discharge to 10% and that's because the voltage out of this thing at "nominal" speed is lower than the standard 5V used on USB ports.

I knew from the start that it's a good for nothing toy but I couldn't help getting it and the first thing I did after unpacking was opening it up.

 It's pretty amazing what 1$ can bring you: intricate lubricated plastic gears, a DC motor, a small PCB with the voltage stabilizer, not to mention the plastic housing and the strap. Pity for all the work those asian manufacturers put in it. Seeing that PCB made me think that maybe some of you want to see the schematic also and with a little help from digikey's Scheme It here you have it in all it's glory:

Quite rudimentary but it's good enough for the budget involved.

- It has a red LED that lights up when you spin the crank
- It also has a strap that you can.. do whatever you want with it

- Gave me something to write about in this article

- It's a "junk out of the box" kind of thing