Hi there, from what you have said it sounds like it's maybe a mental issue. Some people have a twitch then get into their head there is something wrong with the bike and just cannot get it out of their head after that. Riding at night does rely a lot more on feel from the bike as your vision is so reduced and also it's reached the time of year where it's wet and cold and this does effect how your bike will feel and ride.
BT021s are a good all round tyre but as with all tyres they do have a sweet spot so to speak which is the point where they operate at their best, this is not only temperate related but wear related too and once they wear past a certain point their performance begins to decrease.
If it's any help pop the bike down to us and we can certainly give it a good once over and check everything for you. If we find anything we think may effect how the bike will feel or ride we can price up to repair or replace anything needed.
