Which one is actually good? How to choose a bike bag
If you use public transportation with your bike in a bag, you can visit many places on a day trip.

Enomoto's most memorable bike-in-a-bag trip was in 2019, when he used a ferry and train to cycle the Shimanami Kaido. This experience was also published on YouTube, and a few people have reportedly attempted the same route.
While bike-in-a-bag travel may seem daunting at first, it becomes easy after two or three experiences. I've used it to cycle in various places, including hill climbs and MTB rides. The first step is to buy a bike bag that fits your bicycle.
I recently used a bike bag on the Shinkansen. The Shinkansen now requires advance reservations for seats with oversized baggage space. This might seem like a hassle, but I see it as a revolution for bike-in-a-bag travel. Previously, I couldn't be sure if I'd find a place for my bike until I boarded the train, but now I can secure a spot beforehand.
There are two types of bike bags: those that require removing both front and rear wheels, and those that only require removing the front wheel.
First, I'll explain the type that requires removing both front and rear wheels.

Ostrich Road 220 Bike Bag Price: 8,833 yen (tax included)
This is a favorite bike bag of Enomoto's, so much so that he has owned two in the past. It has internal dividers for the wheels, designed to prevent scratches to the frame.
Although it takes longer to pack the bicycle into the bag, the stored size is compact, and when empty, the bag can be folded to a size that fits into a bottle cage.
Recommended for: those who prioritize lightweight, group bike-in-a-bag rides, day trips
The end金具 (dropout adapter) included with the Road 220 bike bag is 130mm. For disc brake bikes, a separate 135mm end金具 is required.
Quick Release Type Disc Brake End Hardware
(Ostrich End Hardware for Rear 135mm) 1,870 yen (tax included)
Thru-Axle Type Disc Brake End Hardware
(Ostrich End Hardware for Rear 12mm Thru-Axle) 2,530 yen (tax included)
Next, I will explain the type that only requires removing the front wheel.

Ostrich Chosoku FIVE Price: 9,020 yen (tax included)
While it looks large, the packing time for this bike bag is overwhelmingly faster than the type requiring both wheels to be removed.
This large bike bag allows you to store your bike with the rear derailleur still attached. If you put your helmet or saddlebag in the empty space, it makes it easier to move around on the train.
I own both types of bike bags. I use the type that requires removing both front and rear wheels when doing hill climbs. When I have a lot of luggage, such as when bikepacking, I use the type that only requires removing the front wheel.
Once you master bike-in-a-bag travel to some extent, you won't mind even a large bag. If you usually have a lot of luggage, the easy-to-use Chosoku FIVE is recommended. Once you get used to it, you can pack your bike in 5 minutes. If you're unsure, this Chosoku FIVE is a good choice.
Recommended for: those who find removing wheels troublesome, solo bike-in-a-bag rides, bikes with rear carriers.
Once you master bike-in-a-bag travel to some extent, you won't mind even a large bag. If you usually have a lot of luggage, the easy-to-use Chosoku FIVE is recommended. Once you get used to it, you can pack your bike in 5 minutes. If you're unsure, this Chosoku FIVE is a good choice.
