Viltrox AF 20/2.8 & AF 28/4.5: Firmware updates (a7V support)

New firmware updates were released in December 2025 for the Viltrox AF 20/2.8 and AF 28/4.5 lenses.

The update for the Viltrox AF 28/4.5 is usual.

However, a firmware file (which you should download and copy to a virtual disk) is no longer available for the Viltrox AF 20/2.8. I had to use the Viltrox Lens application for Windows.

Fortunately, it worked.

See also related notes:

• Viltrox AF 28/4.5: Firmware update (PC) (2025-07-21)
• Viltrox AF 28/4.5 (FE): Wide-angle pancake lens (2025-01-24)
• Viltrox AF 20/2.8: Firmware update (V1.1.2) (2024-11-16)
• Viltrox AF 20/2.8 (FE): Ultra wide angle autofocus lens (2024-08-31)

Image albums:

• Viltrox AF 20/2.8 FE
• Viltrox AF 28/4.5 FE

Flyxii FR-701: My new bike

I assembled my new 29+ hardtail bike, using the Flyxii FR-701 carbon frame as the base.

I used the included parts, as well as the new bottom bracket and some parts from my Cannondale Cujo 1.

The used fork is the RockShox Recon RL 29" Boost with 120mm travel (the stock fork from the Cujo 1). To start, I set the handlebars to the same height as on the Cujo 1 by placing 40 mm of spacers below the stem.

I replaced the end caps to convert the rear wheel to support a 12x148 axle.

The rear axle is in the "longer" position. The chainstay [virtual] length is 440 mm (425+15).

I also mounted the 34T chainring.  Due to the raised right chainstay, there is a lot of space.

The clearance between the crank arms and the chainstays.

My first impression is positive. The new bike reminds me of my Cujo 1, but it is lighter and allows for larger wheels. The Vittoria e-Barzo Trail 29x2.6 tires are still mounted, but there is now more space around the rear wheel.

See also related notes:

• Motsuv 34T chainring (2026-02-19)
• Koozer 450: 12x148 end caps (2026-02-17)
• Ztto BB86/24: Twist bottom bracket (2026-02-15)
• Flyxii FR-701: Included components (2026-02-07)
• Flyxii FR-701: More details (2026-02-03)
• Flyxii FR-701 carbon frame (2026-01-23)
• Cannondale Cujo 1 (2018): Specifications (2025) (2025-12-31)
• Vittoria e-Barzo Trail 29x2.6 (2025-12-19)
• Мой новый велосипед: Cannondale Cujo 1 (2018) (2018-10-06)

Image albums:

• Bicycle

Pentax K 30/2.8: Samples [2] - FF - f/2.8

Camera: Sony a7c (FF, 24MP)

Lens: Pentax K 30/2.8 at f/2.8

See also related notes:

• Pentax K 30/2.8: ad (2023-09-15)

Image albums:

• Pentax K 30/2.8

Motsuv 34T chainring

After upgrading to the 12-speed drivetrain, I decided to switch from the 32T chainring to a 34T one. At least, for evaluating.

I chose an inexpensive 9-12SPD-34T Motsuv (for Shimano direct mount).

  

I already have the VXM MT-V86 tool to remove and install chainrings on the Shimano M7100-1 (SLX) crankset. The tool works well.

Unfortunately, I was too lazy to check if there was enough space to use the 34T chainring with the Cujo 1 frame.

The 32T Shimano chainring weighs 118 g, while the 34T Motsuv chainring weighs 69 g.

See also related notes:

• Flyxii FR-701: My new bike (2026-02-23)

Image albums:

• Bicycle

Koozer 450: 12x148 end caps

The Flyxii FR-701 frame uses a 12x148 rear axle. That was the main reason I chose it. However, my rear wheel is QR 141.

Fortunately, the Koozer 450 Boost rear hub can be easily converted by replacing the end caps.

The Q20 and Q22 caps should be replaced with the T20 and T22 caps.

Also I already installed Koozer T38 hub caps (RockShox torque caps)

See also related notes:

• Flyxii FR-701: My new bike (2026-02-23)

Image albums:

• Bicycle

Ztto BB86/24: Twist bottom bracket

Since the Flyxii FR-701 frame has a compatible with "BB92" (press-fit 41mm x 92mm) bottom bracket shell, I need to find a new bottom bracket.

Overall, I am not a fan of press-fit bottom brackets, so I chose a "twist" bottom bracket from ZTTO.

The ZTTO BB86/24 (LKBB8624).

It has a self-pressing (by twisting) design. Also, it is compatible with Shimano's 24mm spindle crankset, such as my Shimano M7100-1 (SLX).

See also related notes:

• Flyxii FR-701: My new bike (2026-02-23)

Image albums:

• Bicycle

Pentax DA 14/2.8: Samples [3] - APS-C

Camera: Pentax *ist Ds (1.5x crop factor, 6MP), Pentax K10D (1.5x crop factor, 10MP)

Lens: Pentax DA 14/2.8 at f/5.6-f/9 (21mm equiv.)

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

(K10D, f/8)

(*ist Ds, f/5.6)

(*ist Ds, f/9)

(*ist Ds, f/8)

(K10D, f/8)

(K10D, f/9)

(K10D, f/9)

See also related notes:

• Pentax DA 14/2.8 (2006-12-23)

Image albums:

• Pentax DA 14/2.8

Cannondale Cujo 1 (2018): Frame cracks

The main reason I wanted a new bike frame was to switch from a QR 141 to a 12x148 rear axle.

I had already purchased the Flyxii FR-701 carbon frame when I discovered cracks in the welds between the seat stays and seat tube of my Cannondale Cujo 1 (2018).

This was an unpleasant surprise. Thereby, the new frame became a necessity instead of a whim.

Overall, I liked the Cannondale Cujo 1 bike, but I was disappointed by its lack of reliability (pedals, crankset, hubs, dropper post) and durability (frame). In any case, I'm keeping some components from the Cujo on my new bike based on the Flyxii frame.

See also related notes:

• Flyxii FR-701 carbon frame (2026-01-23)
• Cannondale Cujo 1 (2018): Specifications (2025) (2025-12-31)
• Мой новый велосипед: Cannondale Cujo 1 (2018) (2018-10-06)

Image albums:

• Bicycle

VIOFO A119 Mini 2: My new dash cam

I have been using the TrendVision TDR-719S dash cam since 2016. While it provides good video and audio quality, it is rather unreliable.

So I decided to replace it with the VIOFO A119 Mini 2. It supports GPS, which is required for time synchronization.

(Comparing with the TrendVision TDR-719S)

The VIOFO A119 Mini 2 works well with the SanDisk Ultra microSDXC 128GB (for Chinese market).

However, the VIOFO A119 Mini 2 uses a bitrate that is too low, which causes issues with video quality. Therefore, it is important to select the appropriate resolution and FPS.

See also related notes:

• Sandisk Ultra microSDXC 128GB (for Chinese market) (2024-07-19)
• Мой новый регистратор TrendVision TDR-719S (2016-10-20)

Image albums:

• Video

Flyxii FR-701: Included components

The Flyxii FR-701 frame comes with different components, depending on the price.

My frame includes the following components (see also details about the frame):

1. The rear derailleur hanger (29 g) is very specific.

The inner part is attached to the frame with a screw. Meanwhile, the outer part is fixed only with an axle. If the axle is removed, the outer part of the hanger may fall off and be lost.

The outer part can be placed in one of two ways ("flip chip"), either for the "shorter" or "longer" axle position.

2. The rear axle (50 g) is 12 mm x 148 mm with an M12x1.5 thread.

3. The Post Mount brake adapter (46 g with bolts) is also specific.

The frame has a Flat Mount; its placement is for the "shorter" axle position. Using a standard Post Mount adapter will also result in the "shorter" axle position.

However, the included the Post Mount adapter has two additional holes shifted for the "longer" axle position.

4. The headset (121 g with a expander plug; 76 g without it) includes two bearings.

The upper bearing measures 41.8x30.1x7 and is marked 6B 7HXOD41.8x45°x45°.

The lower bearing measures 52x40x8 and is marked 15 8H*52*40*45°*45°.

Do these markings refer to the NECO NHB-6B and NHB-15 bearings?

5. The 37 mm seatpost clamp (24 g).

The 37 mm size is rather rare.

6. Two bolts (6 g) for the water bottle cage bosses.

7. Three internal housing covers.

(a cover is removed from the frame)

See also related notes:

• Flyxii FR-701: My new bike (2026-02-23)

Image albums:

• Bicycle

Samsung NX 10/3.5 Fisheye: Samples [2] - APS-C

Camera: Samsung NX300M (1.5x crop factor, 20MP), Samsung NX500 (1.5x crop factor, 28MP)

Lens: Samsung NX 10/3.5 Fisheye at f/5.6-f/9 (15mm equiv.)

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

See also related notes:

• 10-16-20-30: объективы Samsung NX, новый NX 10/3.5 FE (2014-02-06)

Image albums:

• Samsung NX 10/3.5 Fisheye

Flyxii FR-701: More details

The Flyxii FR-701 is a 29+ carbon MTB hardtail frame, designed for a 100mm travel fork (axle to crown 506 mm with 51 mm offset). Here are more details about the frame.

A noticeable feature is the two positions for the 12x148 rear axle. The distance between the two positions is about 15 mm. This allows you to choose between shorter and longer chainstay length and wheelbase.

(rear derailleur hanger mounts)

Supported wheel sizes are up to 29x3.25 (as stated).

A tapered (1 1/8" - 1.5") integrated headset is used.

The bottom bracket is "BB92" (press-fit 41mm x 92mm) compatible.

It looks like there is no way to install a front derailleur because there are no mounts. And the derailleur cannot be mounted with a band/clamp due to the shape of the seat tube.

The seatpost has a diameter of 31.9 mm and a 37 mm clamp. There is a dropper post routing in the frame.

The rear brake mount is Flat Mount. 

And it is for the "shorter" axle position. In my opinion, the Flat Mount is a good choice for a carbon frame. There are just two holes without thread. If you use a Post Mount brake, the bolts will screw into an adapter.

There are only two water bottle cage bosses, they are on the downtube.

My 19" (L) frame weighs 1340 g without anything attached to it (just frame).

Stated geometry:

According to my measurements, the stated wheelbase (WB) and chainstay length (RC) correspond to the "shorter" axle position.

See also related notes:

• Flyxii FR-701: My new bike (2026-02-23)
• Ztto BB86/24: Twist bottom bracket (2026-02-15)
• Flyxii FR-701: Included components (2026-02-07)

Image albums:

• Bicycle