Cathal, don't be too put off. Similar problems exist starting a business in most industries. Whether, in the end it's a success or a failure, you will learn a lot and over all it's good fun.
There is a lot of good info above if you read between what might come across as discouraging.
I started a business manufacturing & selling products (in a different sector) 15 years ago. Initially I thought price was all people looked at - but quickly found my margin had to be higher to be viable but that because I had established a very good reputation, I could sell high quality parts at a premium.
I attended every trade show to talk about, demonstrate & sell product. I sponsored a lot of people & teams with products to test / evaluate and provided ready-written copy for mags - which they are keen to publish (surprisingly!). I also sought niches that had not been exploited by bigger manufacturers and launched products to fill those gaps. It took 2 years to establish the business & break even (and I had a lot of luck!).
I think there are niches in this market - it's just a case of identifying & exploiting them before someone else does. One such is supplying bikes that FULLY meet the current legislation and at the same time are good / useful to ride. There are so many questionably legal ones out there that true peace of mind could be a good USP!
I wish you every success if you start your business - I have the greatest respect for people who try, whether they succeed or not.