I need to replace the handlebar stem on my Carrera TDF Racing Bike, I find the shop supplied stem too long, what I need to know is what size stem I should be looking for, I know I need a 60cm stem but they come in 2 sizes , Oversize and Standard ?

What is the chainset size on this bike, 172.5 or 175.
Also, I would like to lower the gearing to 50/34 for better uphilling.....do you carry these instore for collection of fitting by your staff? Thanks

Can you you fit a pannier rack to this bike? And if so does Halford stock a rack that will fit it?

I am going to to buy a Carrera road bike.

I am 5 ' 10" do I get a medium or large?

Also not sure whether to go for the TDF or the Virtuoso. What is the main differences?

I've never had a road bike before but they don't look as tough as mountain bikes, would there be some sort of weight limit for the wheels/frame?

I've bought a second (upgraded) set of wheels for my Carrera TDF and would like - if possible - to take the opportunity of lowering the overall gearing on this second wheelset by installing a cassette with a wider gearing range (ie: standard TDF cassette is 12-26 teeth, so something with 26-plus teeth on the biggest ring).
What limit does the existing front and rear derailleur set-up have.
I should add... great if it can be done with just a change of cassette, but I don't really want to go to the expense of replacing anything else.

Thanks in advance for any information.