Help with bike sizing

[kingspirit]

Hi All,
I'm looking to get my first droped handlebar gravel bike but really struggling to choose the right size of the bike.
I think I should be a on Medium sized bike, but some manufacturers Medium size has a top tube length of 54.4 cm and some 55 and even 56 this where I get confused which one will be the right one.
I'm 176cm (5.9) tall with a 86cm(34) inseam.
What is your suggestions regarding sizing would be for my height and inseam?
Cheers!

 

[weareHKR]

The best thing to do is go to your local LBS & sit on a few, nowadays it seems almost all manufacturers have their own sizing!
If you look at the bottom of the thread you'll probably see a similar question that has already been discussed several times over!
Or alternatively, use the search bar at the top of the page...

 

[Arrowfoot]

For 176cm height and 86cm inseam, you are looking at size 54 or M for most brands. As LBSs now have limited range a physical check may not be possible.

If you are in between sizes always go for size one down. If your body is not proportional ie longer torso and shorter legs or vice versa, the top tube and other aspects of bike geometry needs to researched for that particular brand and bike type. Watch YouTube videos on bike geometry.

 

[vickster]

I’m slightly taller but similarly long legged.
all my drop bar bikes are M/54 with 100mm stem. I have quite a lot of seatpost showing

 

[Kajjal]

I get stuck between sizes due to having a longer body so ended up going down size for my gravel bike as I was stuck between sizes.

 

[SkipdiverJohn]

You definitely don't want a frame with a long top tube what with having unusually long legs at that height. The trouble is the saddle will end up high in relstion to the bars, so the most important thing if you want comfort is to find a frame where the geometry gives the tallest head tube and therefore stack height for a given length of top tube.

 

[kingspirit]

I’m slightly taller but similarly long legged.
all my drop bar bikes are M/54 with 100mm stem. I have quite a lot of seatpost showing

Exactly, this is what I'm concerned about as seat tubes on size 54 is not that long, for example cannodale topstone 1 in size 54 has a seat tube length just 45 cm

 

[vickster]

Exactly, this is what I'm concerned about as seat tubes on size 54 is not that long, for example cannodale topstone 1 in size 54 has a seat tube length just 45 cm

Why’s that an issue? Just means a compact frame, maybe also gravel bikes have a higher bottom bracket tho (like CX bikes) to get more clearance over rough stuff.
It’s most important that the bike fits you, if new to bikes, don’t buy blind.
I’ve never paid any attention to the seat tube length myself

 

[kingspirit]

Why’s that an issue? Just means a compact frame, maybe also gravel bikes have a higher bottom bracket tho (like CX bikes) to get more clearance over rough stuff.
It’s most important that the bike fits you, if new to bikes, don’t buy blind.
I’ve never paid any attention to the seat tube length myself

Just looks so awkward
The bikes im currently looking is Cannondale Topstone and Genesis Croix De fer 40. In size M they all have a Effective Toptube is 56cm, and according to their size chart i fall under that size. Strange

 

[vickster]

Just looks so awkward
The bikes im currently looking is Cannondale Topstone and Genesis Croix De fer 40. In size M they all have a Effective Toptube is 56cm, and according to their size chart i fall under that size. Strange

Awkward? The seat tube will just be made up of more post
Unfortunately, all manufacturers size their bikes differently, there’s no industry standard.
I think the Croix de Fer comes up big, you’ll maybe need a small and not medium. That’s what i determined when I half considered one. although looking at the height recommendation chart, at 175-178 a medium is maybe right? Although the small has the 54cm TT, which maybe is what led me to the small
If a medium is too big, get a small! I know a 56 is too stretched for me.
You need to go try to sit on a few

 

[battered]

5'9 is almost certainly a Medium. I'm 5'6 and come neatly between the 2 sizes, so I end up on a Small.

 

[vickster]

I think @steveindenmark has a small CDF and is around 5’9

 

[kingspirit]

Awkward? The seat tube will just be made up of more post
Unfortunately, all manufacturers size their bikes differently, there’s no industry standard.
I think the Croix de Fer comes up big, you’ll maybe need a small and not medium. That’s what i determined when I half considered one. although looking at the height recommendation chart, at 175-178 a medium is maybe right? Although the small has the 54cm TT, which maybe is what led me to the small
If a medium is too big, get a small! I know a 56 is too stretched for me.
You need to go try to sit on a few

Cheers i will try to have a sit on them, few month ago i have tried boardman adv 8.9, top tube was 55.5 and seat tube 53, felt pretty comfy on the bike.

By the way, genesis size chart says That size M (its 56m toptube) is from 168 to 176. I'm 176 so should fit on it.

 

[CanucksTraveller]

As per your other thread on the CdF, I'm on a large Genesis frame and I'm 6 foot. Going by height I'm top of L and bottom of XL on Genesis' size chart, but as I mentioned on the other thread, I don't like feeling stretched out.
I'd say you'd be spot on for a Medium Genesis.

Cannondale I wouldn't know, it's a make I've never owned.

 

[vickster]

Cheers i will try to have a sit on them, few month ago i have tried boardman adv 8.9, top tube was 55.5 and seat tube 53, felt pretty comfy on the bike.

By the way, genesis size chart says That size M (its 56m toptube) is from 168 to 176. I'm 176 so should fit on it.

I’m 177, but I know i need a 54cm TT so looking at the dimensions I’d need a S, with a narrower bar.
assuming you’re a man, you may have a longer reach than I do.
I know 56cm TT feel too long for me. My current 4 drop bars are all a 54