I have found it to be a very good allround bike. I have used it around town, on the freeway and around Eastern Creek Raceway. Around town I cannot fault it. On the freeway it is fine, however, the engine feels smoother and the bike more comfortable at 130 km/h than 110 km/h, which is our speed limit.
On a racetrack, the CBX is great fun. I used to ride a GPZ 600, which was much faster and handled far better than the CBX, but I find the CBX is much more fun.
I have done a couple of things which have made the CBX better. The fork springs were replaced with heavy duty springs made by WP Suspensions. They have made the front end much more stable. I put on rearsets which were bought in Japan. They are made by a company called BEET. They are made to suit the CBX. It is easy to put them on and take them off because the original backing plates, master cylinder, etc. stay in place and only the footpegs, brake lever and gear lever need removing.
The rear sets provide a better riding position for twisting roads, but can get a little cramped on longer runs. The only problem is that the new brake lever does not provide as much leverage as the standard one and, therefore, the back brake has slightly less power.
When the original exhaust system rusted out, I replaced it with a 4 into 1 system which was bought from a wrecker. I do not know what brand it is. The bike sounds much better with the new exhaust.
I tried clip-on handle bars for a while, but put the original bars back on, because they were too uncomfortable.
I have a bikini faring which I sometimes use. It is good for highway work, but seems to make the CBX unstable on twisting roads. I think the fairing is too tall. I would like to replace it with a smaller one.
There are several things I plan to do to the CBX in the future. The front brakes will get braided hoses. I would like to put in better brakepads if there are some available. It needs a new rear shock absorber. I want to put on a more modern after-market unit as the rear end is not very stable around medium to fast bends.
The seal between the carburettors and airbox is not good. The rubber has gone bad and has several small holes. I am sure it is affecting performance. I will put pod filters on if they offer better performance or are cheaper than fixing the seals.
I want to put on a Japanese spec. taillight, which includes the indicators, because I think it looks better than the export indicators.
I would also like to replace the wheels, brakes and forks with more modern ones. I have seen several CBX 400's in Japan done like this, and they looked very good.
By the way, I have done many kilometers, including several around Eastern Creek circuit, with my wife as pillion. The CBX handled very well.