Bike tax

I was really pleased when my wife got her car tax bill for our little Peugeot. It is only £35.00 per year a saving on last year of £15.00, so in the hope that my bike tax would be cheaper as it obviously takes up less space on the road, has low emissions etc, I looked forward to receiving my tax bill. However I have found out that instead of being reduced it has been increased; it is now double the cost of our car!

Can you please tell me why groups such as the BMF or MAG have done nothing to address this problem? I was with the BMF for 10 years but I have refused to renew my membership as they have yet to answer my questions on this matter for the last four years.