Hey All, new to the forum and excited to get into road cycling. I am a mountain biker so I have no experience with road bikes. I am looking to buy a giant defy, and the shop has both a M, and a M/L.

Giants sizing chart says I'm a M. My credentials are: 5'9.25" and 32-33.125" inseam depending on if I have shoes on or not. Medium felt good riding, but I couldn't help but think it looked and seemed small. The LBS said he has a M/L to try but needed to assemble it. Question is, what size to get? The size chart starts at 5'11 for the M/L but I do fall within the inseam measurements.

Any help appreciated!

Why not go to the bike shop and get sized on the bike?

I didn't get the feeling they fit bikes other than a few measurements. He did feel the medium would work, though.

I'm 5'8.5"-5'9" and I ride a Giant Defy in a M. I do have short legs though and a long torso, though. Hope that helps.

Wait for him to assemble the ML and try them both. Pick the one that feels better, not just the one they have sitting on the floor.

I purchased a new Defy 1 last August. I'm almost exactly your size. The dealer was closing out the 2015s and only had a M/L in stock. I rode it around the parking lot and decided to buy it, the price was too good to pass up.

I sold it a couple of months ago. I just never felt comfortable on it. The height was fine but the reach was too long for me.

Ride both sizes back to back, and not just a short spin around the parking lot.

Thanks everyone. The fact that the sizing guide says medium also makes me lean that way, as well as the last posters experience. I guess the bike just seems so damn small looking at it. Is Giants size chart accurate or usually off?

I'd say the M, too. It might be a little short in the top tube, but that can be fixed with a longer stem. I'm about your height, and like [MENTION=360395]Nordo[/MENTION], above, I also had a M/L Defy and never got it to fit right. Like you, I have long legs for my height, and in order to make the TT length work, needed an 80mm stem; but even still it was never quite right. Sold it and bought a size 52 Domane. Get the M!

How tall are you? Long arms?

Is it better to go smaller when in doubt?

Reach issues can often be corrected by changing stems, an easy customization. Go ride both bikes and see which feels better.

I am probably going in tomorrow. Was just seeing what other Defy riders are on and if they are similar sizes. On another note, is it dumb to buy a '16 defy 3 now when the '17s are on their way? The LBS is taking about 70 bucks off the price.

Probably no help but 177/82cm inseam here, which is almost identical to you ... normal proportions - torso/arms/etc. I am looking at getting a M.

Yeah it's tough because with mountain bikes, I'm usually in between a M or L. When I saw they make a M/L I figured it would be perfect! Then I looked at the geometry and size guide and realized I'm now in between M and M/L. Good times.

Medium. You are not 'between sizes' in the Defy; you fit squarely on a Medium -- that's why it 'felt good riding it'. Remember too that cycling inseam (inside leg length) is measured without shoes, so at 5'9ish height with a 32" (your first post) or so cycling inseam you should and could be fit perfectly on a Medium.

So I bought the medium today! Loving it so far. I did have a question with size numbers, though. it seems mediums are referred to as 54cm and larges 56 or 58cm. What measurement is this usually? If it's the seat tube, why is the medium for the defy only 48, and the medium-large 51, and large 53 or so?

I ride a defy 1. I'm about 5'10" with a 30" inseam. The medium is very comfortable but the top tube is super short to me. All in all I love the bike though and I'm actually selling my carbon bike because the defy is just too comfortable and I ride it primarily.

interesting, I'm a tad shorter with larger inseam and the reach seems spot on. Maybe longer legs and shorter torso is best for the geo

Somewhat related to this thread, is the Giant sizing chart assuming all measurements are with shoes off? I'm assuming yes.

Get the other bike assembled and ride them both. I may be 1/2 inch taller than you, and ended up on the M/L. This was my first road bike and I road both at the shop. The guy watching me said he thought I would be much more comfortable on the larger frame, and swapped the stem to 90mm from the stock 100mm. It will feel like a very different position than a MTB.

Well, I already got the Medium a while back and it fits great. I just refreshed this thread asking about Giant's sizing chart. I did ride both, and the M/L felt too stretched out. Most likely I could go either way but the Medium just felt right. According to the size chart, M can go up to 5'11"... but thats just going off height. Since I have longer legs I could potentially rock the M/L as well with a shorter stem like you

I'm 6'1" with 34" inseam and bought a ML though according to their chart I should have a large. ( im on the low end of the large sizing chart) The ML feels perfect to mee.

Which one felt best when you rode it?

The medium felt better.

There's your answer. Buy the medium!