SRM PowerMeter SRAM S975 GXP Standard

Am Wochenende war mein persönlicher “Bike Gadget Day”. Zum Radtraining habe ich mir einen sogenannten “PowerMeter” gekauft, der während des Radfahrens meine Leistung in Watt misst und auf meinem Radcomputer anzeigt. Damit kann man sein Training erheblich genauer steuern und auswerten als mit einer reinen Herzfrequenzmessung, die von zu vielen anderen Faktoren (Tageszeit, Ernährung, Stress,…) abhängt.

Meine Wahl ist auf das Produkt einer deutschen Firma gefallen, SRM aus Jülich. Hier wurde der Powermeter 1988 ursprünglich entwickelt und auch heute sind die Produkte von SRM der Standard unter ambitionierten Radfahrern.

Die Inhalte der Packung waren recht übersichtlich: Linke Kurbel, rechte Kurbel mit Kettenblättern und dem eingebauten Messgerät, Garantiekarte, Einbauanleitung für die Kurbel sowie ein Magnet, der das Messgerät aktiviert.

Natürlich habe ich es mir nicht entgehen lassen, die Gewichtsangabe von SRM zu überprüfen. 178g für die linke Kurbel, 644g für die rechte Kurbel, Achse, Kettenblätter und Messgerät. Dazu noch 4g für den Magnet und 122g für das Innenlager. Das macht in Summe 948g und damit 26g mehr als von SRM angegeben – das ist noch im Rahmen.

Zur Montage musste ich erstmal meine alte Kurbel demontieren.

Als erstes musste die Abdeckung der linken Kurbel mit einem Spezialwerkzeug gelöst werden. Danach konnte ich die beiden Inbusschrauben lösen…

…und die linke Kurbel abziehen.

Danach konnte ich die rechte Kurbel mit den Kettenblättern von der anderen Seite herausziehen – was nicht ganz ohne etwas Dreckentwicklung von sich ging. Dann konnte ich das alte Innenlager ausbauen. Offensichtlich hatte der Experte, der das Rad ursprünglich aufgebaut hatte, noch einige Aluminiumspäne vom Gewindeschneiden im Tretlager gelassen.

Somit habe ich mir ersteinmal die Zeit genommen, das Tretlager ordentlich zu reinigen, von Spänen sowie altem Schmierfett zu befreien.

Schon besser…

Danach habe ich das neue Innenlager eingeschraubt…

…und ruck zuck war die neue Kurbel mit dem Powermeter montiert. Hier von der linken Seite…

…und hier von der rechten Seite. Unter der rot-weißen Abdeckung befindet sich die komplette Messelektronik.

Am Sonntag habe ich dann meine erste Fahrt unternommen, knapp 15km von Limburg nach Burgschwalbach. Im Schnitt habe ich 255 Watt getreten bei einer Maximalleistung von 615 Watt. Schonmal nicht schlecht, da geht aber natürlich noch mehr ;-).

Aerobar Computer Mount for Garmin Edge

Update April 2013: There is an improved version of this custom Aerobar Computer Mount – please read this post for more details.

There are several options to mount a Garmin Edge cycling computer on a standard road bike. However, on a triathlon bike, things are not that easy. You could mount the computer on your stem – however, this option is not compatible with bottles mounted between the arms which is the most aerodynamic solution. Another option would be to mount the computer on one of the extensions. Yet, this would be a poor choice in terms of visibility. There is a quite exhaustive thread in the Slowtwitch forum which discusses several options and custom made solutions. I want to share mine ;-).

I took a carbon fiber plate and marked an octagon shape on it.

This was put into a standard bench vice.

The easiest method to cut straight lines into carbon fiber is to use a Proxxon / Dremel machine with a cutting wheel.

In approximately three minutes, the cuts were made.

The next step was to drill two holes each on the left and the right side to accomodate the cable ties.

Afterwards, I took a standard Garmin Bike Mount. However, the extensions of the mount to fit the rubber ties are somewhat redundant.

So I removed them, again with the Proxxon and a cutting wheel.

The result after a couple of minutes – pretty slick.

The trimmed down Garmin Mount will be glued on the carbon fibre plate.

The final mount after gluing.

Mounted between the shifters at the front end of the extensions using two cable ties.

And with my Garmin Edge 500 placed in the mount.

Just on one level with the top end of the extensions.

The weight of the bike mount including the cable ties is just 1g more than the standard Garmin mount including the rubber ties.

In total, it took me about 60 minutes to build the computer mount and I am confident that this is going to be a durable and well working solution.

Custom made Garmin compatible bike mount for Sony Xperia active

Since August 2010, I use a Garmin Edge 500 cycling computer on my triathlon bike, my mountain bike and in a couple of weeks also on our Chariot Cougar Child Carrier while running. November 2011, I bought a Sony Xperia active smart phone since it basically can do everything that my Garmin does: It is ANT+ compatible, features an integrated GPS receiver and even includes a barometer. There are plenty of sport apps available for Android which can be used for running, cycling and plenty of other activities.

Because the Xperia active can be paired to all the existing Garmin ANT+ sensors on my bikes, I thought that it might be a good idea if it could also “pair” to my existing Garmin bike mounts. With this blog, I would like to show you how I achieved just that.

First of all you’ll need an extra cover for the Xperia active. I bought the Billabong edition which included two extra covers.

After that, I measured the dimensions of the Garmin Bike mount.

I figured that I would need two plastic discs to replicate the Garmin mount. The first one should have a diameter of 25mm and a thickness of 1.45mm. The second one should also have a diameter of 25mm, but with two extensions of 1.25mm lenght and 10mm width. The thickness of the second disc should be 1.75mm. I chose carbon fiber as the material, but any other plastic should be fine as well.

Now I needed to glue the two discs on the cover – I chose UHU plus to do so. Essentially, UHU plus is a 2K epoxid glue which can be cured at 70°C in 45 minutes.

During my first attempt to glue the carbon discs onto the cover, I took a clamp and fixed it to my desk.

Afterwards, I used a hair dryer to speed up the curing process.

While performing a static load test, I had to realize that before gluing, I should have removed the Billabong graphics on the cover because this was the breaking point. So I took the second cover, scratched of the graphics and glued the carbon discs for the second time. To ensure a proper curing process, I put it into our oven at 70°C for 45 minutes.

This time, the result was better withstood the static load test.

Sony Xperia active – mounted to our Chariot Cougar using a standard Garmin bike mount. Nice!

Of course I am going to start the Xperia active during cycling from now on. I will report about the long term reliabilty of this bike mount.

Meine Top10-Leseliste

Was lese ich in meiner Freizeit? Hier meine  Top10-Leseliste, sortiert nach Kategorie.

 

Business

  1. Seven Habits of Highly Effective People, Stephen R. Covey
  2. Winning, Jack Welch
  3. Acres of Diamonds, Russell H. Conwell
  4. God Boss, Bad Boss, Robert I. Sutton
  5. No Asshole Rule, Robert I. Sutton
  6. How to Become CEO, Jeffrey J. Fox
  7. Der Fürst, Niccolò Machiavelli
  8. Sun Tzu Was a Sissy, Stanley Bing
  9. Fish, Stephen C. Lundin
  10. The 48 Laws of Power, Robert Greene

Sports

  1. I’m here to win, Chris McCormack
  2. Das große Laufbuch, Herbert Steffny
  3. Chi Running, Danny Dreyer
  4. Total Immersion Swimming, Terry Laughlin
  5. Dave Scott’s Triathlon Training, Dave Scott
  6. Das Prinzhausen-Prinzip, Jan Prinzhausen
  7. Triathlontraining, Hermann Aschwer
  8. Gut zu Fuß, ein Leben lang, Christian Larsen
  9. Die 50 wichtigsten Übungen: Kraft, Flexibilität und Koordination für Triathleten, Nina Eggert
  10. Grundlagentraining für Radsportler, Thomas Chapple

Travel

  1. Fahrrad Weltführer, Helmut Hermann
  2. The Serious Hiker’s Guide to Hongkong, Pete Spurrier
  3. Lonely Planet New York
  4. Merian Reiseführer China, Julia Berg
  5. French Revolutions: Cycling the Tour De France, Tim Moore
  6. The Leisurely Hiker’s Guide to Hongkong, Pete Spurrier
  7. Lonely Planet Vietnam
  8. Tauchen de Luxe, Tim Simond
  9. Gebrauchsanweisung für China, Kai Strittmatter
  10. Lonely Planet Japan

Entertainment

  1. The God Delusion, Richard Dawkins
  2. Angels and Demons, Dan Bown
  3. The Sun Also Rises, Ernest Hemingway
  4. Digital Fortress, Dan Brown
  5. The Da Vinci Code, Dan Brown
  6. Tom Sawyer and Huckleberry Finn, Mark Twain
  7. The Lost Symbol, Dan Brown
  8. Deception Point, Dan Brown

Review: Ikelite 6242.95 for Canon Powershot S95

In January 2011, it was finally time to combine two hobbies of mine: Photography and Diving.

After reading the very positive review of the Canon Powershot S95 by Ken Rockwell, I decided to purchase this camera in November 2010 and I am very happy about its performance.

If you consider using the Canon Powershot S95 also for underwater photography, there are two options to do so: The Canon WP-DC38 housing which comes at a price tag of roughly 180 USD and the Ikelite 6242.95 that will set you back about 325 USD. At the time I had to make the purchase decision, there were no reviews available. Hence, I decided to base the decision on the thought: “Product sold at higher price offered by a company specialized on engineering products for a special purpose should offer superior quality and functionality.”

So I bought the Ikelite housing. And used it first during our 12 dives around Ko Lanta in January 2011. After shooting roughly 800 pictures underwater with the combo Powershot S95 / Ikelite, I want to share my experience with this review.

1. What’s in the box?

It’s delivered in a neutral white box 🙂

Contents

1x Housing

1x Lens Cover

1x Diffuser

1x Reflector

1x Plastic Ring for Front Control Ring access

1x Wrist Strap

1x Silicon Lube

5x Spare Knobs

1x Manual

1x Warranty Card

 

 

2. Setup

The setup is rather easy. First, you have to press the plastic ring on the front control ring.

Camera without Ring

Camera with Ring, half way on

Camera with Ring

Afterwards, you should make sure that the knob to control the zoom lever is aligned properly.

Zoom Lever, properly aligned

Zoom Lever, not properly aligned

Then you can put the camera into the housing. Make sure that the teeth of the control ring adapter snap in properly. Close the lid and snap the lever.

The last check should be to turn the housing around and check whether the O-ring shows a deep black continuous line, approx. 4mm wide. Then you can be sure that the housing will be waterproof. I used to do a brief test in the water reservoir of the dive boat prior to each dive.

If you plan to use the camera integrated flash, make sure that you attach the flash diffuser to the housing with a short robe – I recommend floss to do so.

Before the first dive, I would recommend to play around a little with the camera in the housing to familiarize yourself with the controls. Especially using the shutter release button, to get used to the pressure point of the rear controls and the necessary button combinations to switch the internal flash on and off.

3. Observations during usage

If you feel comfortable using the S95 above water, you will feel the same way using it in the Ikelite case below the surface. All menus are accessible but given a proper camera setup before the dive, there is no need to do so.

Build quality and usage of buttons

The build quality of the housing is convincing. All buttons are big enough and easy to use underwater, even the ones with rather narrow spacing that trigger the rear control dial. You get a decent mechanical feedback whether you pressed the button far enough. As I only used it in warm water so far, I cannot really judge whether this is also true for usage wearing thick gloves. The housing is neutrally buoyant, I did not feel the need to attach any weights to trim.

Using internal flash

The internal flash can be used in combination with the included diffuser – without it, the lens port would cause a huge shadow in the lower right corner of the picture. You can definitely use the integrated flash to take macro shots up to a distance of roughly 0.3m. Objects further away than that will lose color immediately. After trying it for a couple of shoots, I didn’t even bother to use it anymore during the next ten dives.

Strong vignetting without the flash diffusor

Much less vignetting using the flash diffusor

Maintenance

After each time I opened the case, I checked if there was any water in the case – nil. Before closing it again, I made sure that there wasn’t any dust or even bigger particles attached to the O-ring. The lubricant might facilitate this. However, there was never any problem because we did only boat dives during that vacation. If you use the housing in dusty or sandy areas, e.g. beach dives, I would perform this check more carefully. After one week and twelve dives, I completely removed the silicon lubricant and put a small portion of fresh lubricant on the O-ring before I stored the case.

Other than that, I would highly recommend to rinse the housing carefully after each dive, especially after diving in salt water. If you don’t do so, you can immediately feel an increase in the knob resistance. I used to put the housing in one of the fresh water tanks on our boat after each dive.

Fog

I did not have any problems with fog inside the camera housing. This might be different under conditions with larger difference between air and water temperature – however, I can’t judge this so far.

Potential overheating problem

During second half of the second dive, the camera suddenly did not accept any commands any more except for the shutter release. Images were of proper quality and stored to the SD-Card as usual – I was just not able to access any menu anymore, e.g. to adjust the white balance. I was under the impression that I did something wrong and did not bother anymore during the dive. One day later, during the third dive on that day, the same happened so I could be sure that it wasn’t me. After the dive, I asked myself about similarities between the two dives when the problem occurred. I found that prior to both dives, I left the camera in the closed housing but watched a lot of the images of the past dives in playback mode. Due to the limited air volume inside the housing, the energy consumption of the camera, the corresponding heat dissipation and the ambient temperature of roughly 28 °C, this might have caused a camera overheating. However, this is only speculation from my side.

I made sure that I didn’t use the camera much prior to the next dives and also kept it away from direct sunlight – no problems occurred afterwards anymore.

4. Tips and Tricks

The first thing I had to learn to achieve decent looking underwater pictures is that constant adjustment of white balance is essential. For each change in depth or angle towards the sun, you have to readjust the custom white balance. Forget about the S95 “Underwater Color Mode” – this is not going to improve anything according to my experience.

Therefore, I recommend to set the custom function button on the rear to “Custom White Balance” – you are going to use this frequently. As reference for “white” underwater, point your left arm towards the object you want to photograph and push the custom function button – this method delivered the best results for me. At least better results than using the flash diffuser as white card.

I set the front ring to exposure compensation. You won’t need this feature much but still it’s valuable to have direct access to it. Other than that, I set Auto ISO to “on” with a maximum of 200.

5. Extension Capabilities

External Strobe

The Ikelite Housing brings the capability to attach two AF35 external strobes, Type 4035. They will be triggered by using the reflector instead of the diffuser. Up to now, I did not gather any experience with these add-on strobes – more to come in the future.

Wide Angle Converter

Due to light refraction, everything in water appears to be roughly 33 percent larger than above the surface. This means that the effective focal length changes from 28-105mm to 42-158mm. To compensate for this effect, Ikelite offers a wide angle conversation lens (type 6420) with a magnification of 0.56x. Using this converter, the effective focal length will be 23.5-88mm. Again, I did not gather any practical experience with this extension – more to come in the future.

6. Summary

I am really impressed with the ease of use, the build quality and the functionality of the combo Ikelite / Canon Powershot S95. With a total invest of currently 750 USD, you are going to get a solution to take underwater photographs and videos with a decent quality at a very reasonable cost / quality ratio. An underwater housing for a DSLR would set you back roughly twice as much – not including the DSLR, lenses, necessary dome ports or external strobes.

Hence, I highly recommend the Ikelite for those divers that want to take decent pictures underwater but do not need to earn a living with it. At the same time, this is a solution where you don’t need to worry whether you are endangering the “well being” of you nice little Powershot S95 due to poor engineering of the case itself.

You can purchase the case here or here.

Please feel free to leave a comment to share your experience or ask unanswered questions.

7. Sample Gallery