Bike Frame Size and Position

James needs a little advice on his frame size, but we think he has probably worked his size out already, so we give him a few pointers on what to do after a professional bike shop has set him up

How do you choose a frame to start with? I measured my inseam as 34″ I think, I need a 54CM frame?
I plan to purchase a Mercia aero tt and will have it fitted at a professional bike shop.

Hi James,
It sounds like you have all the measurements correct, I have found over the years that I now ride a smaller frame than ever, I’m not shrinking, I don’t think, but I have definitely changed my riding position or maybe just refined it slightly with each new bike.

Good idea to get some professional help with fitting your bike, they know a lot about different body sizes and your building a time trial bike so this is different again from a normal road position, more aerodynamic for a start!

Remember that when you are set up on the bike you may need to just tweak your position a little here and there. By moving the saddle 1 mm up or down can make a big difference to your comfort and your power output. Whatever you do when you find the correct and best position, measure the position and write it down and do go changing it too much, a little at a time or you could give your self an injury. Good luck with your bike and you can always send us a photo of it when it’s ready for the road.