Hello.
I was at school when I bought my first Road Bike. A Peugeot PX10LE full 531 race bike. I was fourteen.
How old are you?
Because I was 14, a Junior, the gearing was restricted to 52 x 14 ( 7.93 m development ). I COULD NOT fit a 13 sprocket or a 53 ring or I could not compete.
If you are thinking of entering Junior class races, check your gearing on the Boardman. If its a 50 big ring, you will need to throw out the 13, 12 and 11 sprockets.
Before you go into
Halfords and order your Boardman ( excellent bikes ), take a look at your Dad and his Brothers, and maybe your Mom and her brothers, if any, to get an idea of how you will grow.
When I bought my Peugeot, the sizing method then was Seattube L = 1/3 x height ( French fit ).
Since then, things have got simpler still. Stand over the bike and you should have about 40mm between the very top of the top tube ( right next to the head tube ) and your crotch WHEN YOU ARE FULLY GROWN.
My Pug is 57cm and I have a perfectly fitting 54cm SWorks. To stand over the Pug, I have to stand on the front portion of my shoes with plates and curved sole to put my heel 2" off the ground.
Nowt wrong with Boardman's bikes. They are race-ready, for adult classes