Frame Size

[techsupport]

Hi,

I am looking to buy a road bike and I have a question regarding frame size. I am 178cm or 5'10' I see in the sizing guides I can use a M/L which is for heights 170-178 or the L which is for heights 178-186. Would I get the M/L or L? or is that part of the bike fit?

[10speedsemiracer]

Much more accurate to actually go and try the frame, as there is a lot of variance between manufacturers, and even between models because of geometry differences. If possible, go into your LBS and try both an M and an L.

If that's an option.

[madmacca]

Generally speaking, it is easier to fit someone to a frame that is slightly too small, than it is to one that is slightly too large.

That said, torso length is more important to frame sizing than overall height, and this can vary between people of the same height. So you need to see how YOU feel on THAT bike.

[CKinnard]

The smaller frame has more options to fit you = use a longer stem, head tube spacers, and an after market seat post. The smaller frame will also be slightly lighter and stiffer.

If you are uncomfortable on the larger frame, there's less options to adjust fit.

Although this may not apply to you, a lot of pro riders use the next size down frame because they want to get the stem lower, and a smaller frame can be more agile i.e. shorter wheel base, lower stem helps lower the center of gravity.

[Duck!]

Most manufacturers will have some overlap in their sizing suggestions, to allow for different riders having different leg:torso proportions. A longer leg/shorter torso person will generally find the smaller frame more comfortable due to the shorter reach, the shorter leg/longer torso rider will typically go for the larger frame for its longer reach. Try both and see what you're more comfortable on.

[bychosis]

I have bought a couple of frames online, but I am able to determine the basic fit using my existing bike measurements/geometry. I have ridden bikes from medium to XL depending on the style of bike, the mediums can be a bit short. At 180cm I also have a long torso/short legs which is why I can get away with XL for top tube length

[CKinnard]

And not all long torsos are the same. Someone who is 20yo and flexible can reach a lot further than a 50yo with a stiff spine.

[foo on patrol]

^^^^ You been spying on me? ^^^^

Foo

[CKinnard]

^^^^ You been spying on me? ^^^^

Foo

nah Foo. after you mess with 15,000 spines you can generalize confidently!