malykh.com notes: 2026-03

2026-03-21

Split crown race

The headset that came with the frame includes a fork crown race ring (39.8 mm). However, when I installed the headset, I used a split crown race instead.

A split crown race is easier to install and remove.

See also related notes:

Flyxii FR-701: My new bike (2026-02-23)
Flyxii FR-701: Included components (2026-02-07)
Flyxii FR-701 carbon frame (2026-01-23)

Image albums:

Bicycle

2026-03-19

Anastigmat Victar 50/2.9: Samples [2] - FF - f/2.9

Camera: Sony a7c (FF, 24MP)

Lens: Anastigmat Victar 50/2.9 at f/2.9

See also related notes:

Anastigmat Victar 50/2.9 (M40x1): Uncoated triplet from 1940s (2023-07-24)

Image albums:

Victar 50/2.9

2026-03-17

Race Face Chester: Flat pedals for winter

My new flat pedals for the winter season.

They are the Race Face Chester Yellow (PD20CHEYEL).

I have tried them out, and they are much better than my previous cheap ESLNF flat pedals, which had a lot of free play.

Image albums:

Bicycle

2026-03-15

http:// -> https://

All http-links to malykh.com and malykh.blogspot.com have been replaced with https-links in all posts.

2026-03-13

Vittoria e-Barzo Trail 29x2.6: Tubeless mount

In 2019, I tried to make tires tubeless on a few occasions (see 1 and 2). However, the rims were not suitable for this.

This time, I have a different set of tires and wheels. So, I tried it again.

I installed these tire valve stems.

I used inexpensive "universal" (for bikes, motorcycles, cars, and so on) tire sealant. Since it is winter, I mixed the sealant with antifreeze/coolant.

It works well. I already rode 300+ km without any problems despite the cold weather. This may be due to the relatively low tire pressure. I use 1-1.5 bar (14-21 psi), or even less.

It will be interesting to see how it goes in the summer with the different tires I want to use.

See also related notes:

Vittoria e-Barzo Trail 29x2.6 (2025-12-19)
Koozer XM1850 (622x27) wheelset (2024-06-29)
Антифриз Coolstream JPN (2020-04-10)
Бескамерные покрышки на Cujo 1: вторая попытка (ободная лента и вентиль) (2019-09-13)
Бескамерные покрышки на Cujo 1: первая попытка (2019-06-11)

Image albums:

Bicycle

2026-03-11

Pentax Q 01 8.5/1.9 Standard Prime: Samples [2] - 1/1.7" - f/1.9

Camera: Pentax Q (1/1.7", 12MP)

Lens: Pentax Q 01 8.5/1.9 Standard Prime at f/1.9 (39mm equiv.)

The profiled lens (distortion/vignetting) correction is disabled.

I was disappointed with this lens when used on the Pentax Q. However, the Pentax Q7, which has a larger sensor, produces better results. The angle of view is wider, and the resolution is higher. This combination is quite usable. One notable issue is distortion. I wish it were less.

See also related notes:

Pentax Q 01 8.5/1.9 Standard Prime: Samples [1] - 1/2.3" - f/1.9 (2025-10-07)
Pentax Q 01 8.5/1.9 Standard Prime (2025-09-23)

Image albums:

Pentax Q 01 8.5/1.9 Standard Prime

2026-03-09

Additional seatpost clamp

The PostFix BSP-97 is an additional clamp (27.2mm, 31.6mm) that is installed directly onto the seatpost, on top of the frame's seatpost clamp. It is very useful for a carbon frame.

I wanted to make something similar for the 31.6mm seatpost. For the base, I used a standard seatpost clamp for a 31.8mm seat tube. However, such a clamp has a lip that secures it to the seat tube.

This lip must be removed. I used a grinder to do so.

After all, I have two versions of processed clamps.

The two-bolt clamp (40g):

The one-bolt clamp (21g):

Both work well.

Why don't I use a dual-size seatpost clamp? They are 31.6mm/34.9mm, usually. But I need one that is 31.6mm/37mm.

See also related notes:

Flyxii FR-701: More details (2026-02-03)
Подседельный штырь Reverse Style Lite (2020-12-05)
Дремель (2009-09-04)

Image albums:

Bicycle

2026-03-07

VIOFO A119 Mini 2: Bitrate problem

The VIOFO A119 Mini 2 dash cam has a quite good sensor and lens. However, the main problem is too low bitrate, even with proper settings.

The video quality is good for static scenes. While motion of the car introduces too many artifacts.

For testing, I recorded the same scene with the maximum bitrate setting for each mode.

2592x1944 30fps 29870kbps

2560x1600 30fps 30207kbps

2560x1440 60fps 26845kbps

2560x1440 30fps 30800kbps

2560x1080 60fps 30737kbps

2560x1080 30fps 30931kbps

2304x1296 30fps 24874kbps

1920x1080 60fps 25077kbps

1920x1080 30fps 22855kbps

Yes, the bitrates are too low for high resolutions.

Also, there is no any resizing. A smaller resolution results in a smaller angle of view due to cropping.

I chose the 2560x1080 30fps mode. The 21:9 aspect ratio is suitable for a dash cam (and I also used the WideHD 2560x1080 mode with the TrendVision TDR-719S).