what size bike

The precise size will vary depending on how long your legs, arms, and torso are. If you've got compatatively longer legs, you should get a bike with a slightly longer seat tube and a shorter top tube. Etc. Ideally, you'd get a good bike shop to set you up precisely on a few bikes and then let you test ride them. If you're set on buying online, you could try a calculator: cyclemetrics.combike fit links.htmOpen ↗. It'd still be advisable to get advice from a good local bike shop on saddle and stem/handlebar setup.

kittycattykitty said:

I'm 164cm tall, what size road bike would i need - in cm plz

different manufacturers size their bikes differently.

give us more info (brand of bike you like, type of riding you would like to do) to help you.

5'4" tall person? Size small road bike with 650c roadie rims or XC (extremely narrow) 26" (559) mountain bike rims.

And, you should test drive.

If the handlebars seem short, the bike is too small. If you strike the top tube with your. . .um. . ."goodies" then the bike is too big.

Get the tallest you can ride without endangering your. . . well, I'm outta here.