Hi,
what size of Gt Gtr Series road bike is best for a rider 5 '.9.75 "(177 cm) tall ?

What's your inseam? Can I assume you are male?

The only real way to tell is to throw your leg over the bike and see.

male,
inseam 84 cm (33").

I question why we'd want to bring pants inseam into this when your last sentence is the real test anyway.

Test ride Bikes in the Shops in Person. drool over your keyboard on stuff you cannot afford on the web.

Hey all,

I am looking to get into road biking and have been pretty confused by frame size. From what I understand its the length from the crank (the part where the pedals are?) to the place where the saddle is inserted. I know, I am a whiz with the correct terminology. I bought a hybrid bike a few years ago and it had a 20 inch frame (about 50.8cm) and it fit just fine.

I am 181.7cm tall (5ft11),
my pants inseam is around 33inches (around 83cm).

I am currently looking at road bikes and have found one I like (online). I found a very similar one at a bike shop which has a 51cm frame. I sat on it and found my toes could barely touch the ground. The bike online has a 52cm frame.

My problem is that every forum says that this is pretty small for someone my height, but I felt like the 51cm frame was a little big so I am torn between what these people are saying and what I experienced. I am obviously a complete novice when it comes to road bikes and so I suppose my question is what do you think? If the 51cm frame bike was a almost a little too big would it be best to assume that maybe my proportions just lend themselves to a 52cm (ish) frame (or even the 51cm frame at the LBS). The dude at the shop said that the bike I tried would be fine for me. Another problem is that I live in a rural part of Japan at the moment and I would have to order in a larger framed bike and I am pretty sure it would be very expensive (if it even could be ordered in). My friend told the bike shop he would need a 60cm frame and they acted like such a massive bike surely couldn't exist.

either way this is the bike I was thinking of getting.

https://www.amazon.co.jp/gp/product/B...A11G6841CDJZU3

Any advice would be very much appreciated and if you need any help translating the Japanese just give me a shout.

Thanks everyone.

I am similar in size to the Op, my conventional road bikes are 53 and 55.5 square, the slightly bigger frame runs a stem that is 20 mm shorter (80) and is not quite as aggressive a fit with less saddle to bar drop.

Top tube length is most critical for proper fit, people of identical height may have different reaches and different levels of flexibility.