Beginner needing advice

p_ano_man said:

I have found a decently priced road bike on ebay. I was wondering how I could go about finding out what size I need. The bike I found is a small which has a standover height of 29 inches. I think that would work for me, but not sure. Is it safe to buy on ebay or should I go to a bike store? I didn't want to pay the prices that are at bike stores.

A little more information...I am 5'6" tall, if that makes any difference.

My first recommendation is to pay for a professional fitting.

While there are great deals on Ebay, most new cyclists don't know a department store bike from a boutique bike. Do some extensive research and do not make an impulse buy.

All that aside, here is an online fit calculator:
competitivecyclist.comCCYOpen ↗

And another a little less in depth:
coloradocyclist.combikefitOpen ↗

p_ano_man said:

I have found a decently priced road bike on ebay. I was wondering how I could go about finding out what size I need. The bike I found is a small which has a standover height of 29 inches. I think that would work for me, but not sure. Is it safe to buy on ebay or should I go to a bike store? I didn't want to pay the prices that are at bike stores.

I think that ebay is great for the experience buyer, but can be risky for the novice. It won't be a bargain if you get a poor fitting bike on ebay that you can't return. If you are budget conscious, try finding a nice used bike locally. At least you can try it out.

Predicting bike frame size from height is very difficult as several things reflecting unique body proportions and other factors (leg length, torso length, back flexibility, arm length, etc... go in to getting a good fit on the bike).