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2025-12-23

Cannondale Cujo 1: Vittoria e-Barzo Trail 29x2.6 mounted


Since I only have one 29" wheelset, I used them. The rims' inner width is 27 mm. This is less than the recommended 30c/i30 rims, however, the difference is negligible.

Also, I have no 29+ inner tubes, so I used 29x1.9/2.3 ones.

The tire carcass width is about 60.3 mm at 2.4 bar pressure (whereas 65 mm is expected).




Nevertheless, the 29x2.6 tires have a noticeably larger diameter than the 27.5x3.0 tires have.

This is a radius (sic!) comparison. The 29x2.6 tire is on the i27 wheel and the 27.5x3.0 tire is on the i35 wheel. Both wheels are on the single axle.




Fortunately, the ready wheels fit Cujo1 well. There is enough space between the wheels and the frame for snow driving.




The fork (RockShox Recon RL 29" Boost 120mm):




The seat tube:




The seat stays:




The chain stay:




First impressions are good. This tire is quite good for driving in the snow.

Posted by malykh в 16:23 0 comments

2025-12-21

Auto-Takumar 105/2.8: Samples [2] - FF - f/2.8

Camera: Sony a7c (FF, 24MP)
Lens: Auto-Takumar 105/2.8 at f/2.8










See also related notes:
Posted by malykh в 10:58 0 comments

2025-12-19

Vittoria e-Barzo Trail 29x2.6

Even when used only on the front wheel, the 27.5x3.0 tire performed well in the snow. After that, I decided to try wide 29" tires on both the front and back.

The best options would be 29x3.0 or 29x2.8 tires. However, this 29+ standard is almost obsolete, as few tires are available in this size. I am also unsure if there is enough space to mount such large wheels on the Cujo 1.

Therefore, I chose 29x2.6 tires.




These are Vittoria e-Barzo Trail 29x2.6 tires. I was confused by with the "e"-name, but these are actually rebadged Barzo tires for standard mountain bikes.




The ETRTO size is 65-622. The tires are foldable, of course. 120TPI. The maximum pressure is 2.5 bar or 35 psi. The recommended rim size is 30c/i30.

The weight (without packaging): 831g and 815g.

I selected these tires because of their 120 TPI (a high level), 35 psi (lower is better), and notably lighter weight (less than 1 kg).


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Posted by malykh в 10:48 0 comments

2025-12-17

Pentax Q7: Angle of view with 03, 04, 05 lenses

The Pentax Q7 has a larger 1/1.7" sensor (4.6x crop factor, 12MP) than the Pentax Q and Q10 models (1/2.3", 5.6x crop factor, 12MP). This means that the same lenses provide a wider angle of view with the Q7 (and the Q-S1).

Pentax Q-mount lens lineup:



Note, that the equivalent focal length is shorter for the Q7, but there is some deviation with the 03, 04, and 05 lenses. Their equivalent focal lengths are larger than expected for a 4.6x crop factor.

I tested the Pentax Q7 with my lenses and discovered the reason.

With the 03, 04, and 05 lenses the Pentax Q7 in JPEG crops the image to ~9.9MP and upscales it to 12MP. This makes the angle of view narrower. In DNG, the full 12MP image is stored, but the metadata contains crop information (like the Ricoh GR).

Default Crop Origin             : 185 139
Default Crop Size               : 3629 2722

Therefore, the actual angle of view depends on the RAW converter used.

The ART RAW converter ignores the crop information, and works with the full image. If your RAW converter doesn't offer this flexibility, you can use ExifTool to remove the crop information.

Here are my tests.

Pentax Q 03 3.2/5.6 Fish-eye

Pentax Q:




Pentax Q7 (JPEG):




Pentax Q7 (DNG without cropping):




Pentax Q 04 6.3/7.1 Toy Lens Wide

Pentax Q:




Pentax Q7 (JPEG):




Pentax Q7 (DNG without cropping):



Pentax Q 05 18/8 Toy Lens Telephoto

Pentax Q:




Pentax Q7 (JPEG):




Pentax Q7 (DNG without cropping):



As you can see, the angle of view in Q7's JPEG of the 03, 04, and 05 lenses is wider than with the Pentax Q, but narrower than the full image without cropping.

Posted by malykh в 19:24 0 comments

2025-12-15

Cannondale Cujo 1: 27.5x3.0 and 29x2.1

This is the setup of my Cannondale Cujo 1, that I started using this winter.




Front wheel: WTB Ranger 27.5x3.0 on an i35 rim.
Rear wheel: Kenda Small Block Eight 29x2.1 on an i27 rim.

Since the summer of 2024, I have used 29x2.1 tires, but this winter, I wanted to switch back to 27.5+ (27.5x3.0) tires. Unfortunately, the rear 27.5" rim is broken, so I only changed the front 27.5+ wheel, and kept the 29" rear wheel.

The diameters of the 27.5x3.0 and 29x2.1 wheels are almost the same, with the 29x2.1 wheel being very slightly larger.

I have already noticed an improvement when driving in the snow. 





See also related notes:
Image albums:
Posted by malykh в 19:03 0 comments

2025-12-13

Pentax M 135/3.5: Samples [3] - FF - f/3.5

Camera: Sony a7c (FF, 24MP)
Lens: Pentax M 135/3.5 at f/3.5

In my opinion, the Pentax M 135/3.5 is a nice, compact, inexpensive lens from the film era.








Posted by malykh в 11:25 0 comments

2025-12-11

My SLIK *pods (2025)

These are my SLIK simple aluminum tripods and monopod.




From left to right:

SLIK Sprint CG
SLIK Monopod 350

I bought them all used, except for the SLIK PRO 500 DX. Used SLIK tripods are underrated, which is why I was able to find these at affordable prices.

I would also like to obtain a SLIK PRO 700 DX (quite large tripod!), but they are rather rare.



Image albums:
Posted by malykh в 17:41 0 comments

2025-12-09

Cannondale Cujo 1 (2018): 12-speed drivetrain (weights)

I recorded all the weights during the process of replacing components of Cujo 1 to 12-speed.

Removed:

-95g // FSA MegaExo Comet BB-7100: Bottom bracket
-871g // FSA V-Drive Boost 148 CKM-7159: Crankset 175mm with 30T chainring

Total removed: -2088g


Mounted:


Total mounted: +1872g


1872-2088 = -216

So, the bike's weight is reduced by 216g. The main reason for this is the heavy stock FSA crankset.



See also related notes:
Posted by malykh в 07:45 0 comments

2025-12-07

Cannondale Cujo 1 (2018): 12-speed drivetrain

I successfully mounted components of a 12-speed drivetrain on my Cannondale Cujo 1.





Mounted components:

Shimano Deore XT BB-MT801: Bottom bracket - The stock FSA bottom bracket is worn out and needs to be replaced.


My first impression is positive. Everything works well. However, I would prefer a 34T chainring. The front 32T and rear 51T are too slow for my needs.



Image albums:
Posted by malykh в 11:25 0 comments

2025-12-05

Mitakon [Zhongyi] Creator 35/2: Samples [2] - 135 film - f/2

Camera: Pentax Super A
Film: Ilford Pan F Plus ISO 50 (135 B&W)








Posted by malykh в 09:54 0 comments

2025-12-03

Meyer-Optik Helioplan and Carl Zeiss Jena Tessar: 40/4.5 both





Both are 40mm. They are both f/4.5 fast. They both have non-retrofocus optical designs (with the M42x1 mount).

I didn't test them side by side. The Tessar most likely has a higher resolution. However, I personally prefer the Helioplan.

Posted by malykh в 22:28 0 comments

2025-12-01

SunRace CSMZ903 WA1 12-speed 11-51T cassette

All of the necessary components for a 12-speed drivetrain were present. However, I was confused by the SunRace CSMZ901 WA1 12-speed cassette, which weighed 597g. It seemed too heavy.

I looked for a lighter, yet affordable, alternative suitable for the [Shimano] HG freehub body. I bought a used SunRace CSMZ903 WA1 12-speed cassette.




The CSMZ903 is very similar to the CSMZ901: its sprockets are 11-13-15-17-19-21-24-28-33-39-45-51 (teeth) too.




The main difference is that the CSMZ903 has three aluminum A7075 sprockets (39, 45, and 51 teeth) instead of the CSMZ901's single 51-tooth sprocket. So the SunRace CSMZ903 WA1 weighs just 498g. This is an attractive weight for a 12-speed cassette.

Posted by malykh в 09:56 0 comments
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