Importance of frame size

[MattDB]

Hi, quick query.

I'm 6'6'' and I'm looking for a entry-mid level road bike - I went into a really big shop and was told that, there was only one bike that I could order in. I'm currently riding a 21" frame with the seat-post at full extension - could probably do with a couple of extra inches but it's not too uncomfortable. But I just wondered what people's thoughts or experiences were in relation to this. There were some lovely bikes in a half price sale - I wondered about getting a slightly-too-small frame then could I get an extra long seat post?

Matt

 

[Cyclist33]

I think often too much is made of it in its own right... it's always great if you can find a bike that when you sit on it it's absolutely spot on, but I feel that is very rare and I have always tweaked ride position after the fact. I think you can probably get away with a size down or up if you're prepared to experiment... it;s about what you want... like I just got a bike that arguably I could have got the next size up, but if I had I would have shortened the stem and dropped the handlebars and brought the saddle forward. I liked the look of the size below that more, it felt racier (relatively) and so I make it fit by dropping the bars and pushing the saddle back a bit. More seatpost showing, which appeals to me.

It makes me want to ride it and that means more than the perfect fit off-the-peg.

 

[MattDB]

But would you be willing to fit a longer seat post? Or would that be a step too far?

 

[raleighnut]

Too much seat post can crack an ally frame, not sure on carbon plus the seatpost itself is under lots of stress.

 

[Cyclist33]

Too much seat post can crack an ally frame, not sure on carbon plus the seatpost itself is under lots of stress.

Within acceptable limits as marked on the post, I don't think it's really a problem. As for fitting a longer post, what's the issue? It's very easy to do and they're easy to come by

 

[MattDB]

I just wasn't sure if it was a good plan buy a bike clearly a little too small Cyclist33. The man in the shop said it would be uncomfortable and I'd wear out the components more quickly, then again this did only leave me with a choice of one bike and I was in love with a retro 5 speed with brown tyres :-).

 

[ColinJ]

I just wasn't sure if it was a good plan buy a bike clearly a little too small Cyclist33. The man in the shop said it would be uncomfortable and I'd wear out the components more quickly, then again this did only leave me with a choice of one bike and I was in love with a retro 5 speed with brown tyres :-).

The 21" bike you are currently riding isn't a 'little bit' too small for someone who is 6' 6", it is way too small! That would be more suited to somebody who is about 5' 8".

You can get a long seatpost to get the saddle up on a tiny bike, but you are then either going to have a huge drop to the handlebars, or you have to have some crazy stem to get the bars into a reasonable position.

You should be looking at frames that are about 63 cm or 25".

You might get away with a bike that doesn't fit if you only ever want to ride 10 or 15 miles, but if you ever want to do longer, harder rides then you will end up in a world of pain if you don't get something that fits you properly!

There is a whole world of bike shops out there - you don't have to limit yourself to a badly-fitting bike from just one of them!

 

[themosquitoking]

I fell almost exactly between sizes when i bought my defy and went for the smaller one, prefer it to being too stretched out. Even fitted a slightly shorter stem too. This might not work for you though.

 

[stephec]

The 21" bike you are currently riding isn't a 'little bit' too small for someone who is 6' 6", it is way too small! That would be more suited to somebody who is about 5' 8".

You can get a long seatpost to get the saddle up on a tiny bike, but you are then either going to have a huge drop to the handlebars, or you have to have some crazy stem to get the bars into a reasonable position.

You should be looking at frames that are about 63 cm or 25".

You might get away with a bike that doesn't fit if you only ever want to ride 10 or 15 miles, but if you ever want to do longer, harder rides then you will end up in a world of pain if you don't get something that fits you properly!

There is a whole world of bike shops out there - you don't have to limit yourself to a badly-fitting bike from just one of them!

This is it.

It's not only the seat post length but the stem you'll need to stop yourself being cramped up will have an adverse effect on the steering.

 

[02GF74]

The 21" bike you are currently riding isn't a 'little bit' too small for someone who is 6' 6", it is way too small! That would be more suited to somebody who is about 5' 8".

You should be looking at frames that are about 63 cm or 25".
one of them!

Yes - rough rule for frame sie is 1/3 your height - I ride 23/24" in road frame and I'm 6 ft 1, so the sizes above are about right.

Wait for the sales, the extreme size, XS,S, XL are the ones that don't sell so are usually most discounted.

 

[Gravity Aided]

i'm 6'4"and ride 23 hybrid/tourer -25 road, and 19 in a mountain bike, because that's as big as they make it. Ribbles winter audax frame goes to 64cm, that may be more your size

 

[simon.r]

The 21" bike you are currently riding isn't a 'little bit' too small for someone who is 6' 6", it is way too small! That would be more suited to somebody who is about 5' 8".

That's assuming a road bike. I'm 6'2" and ride a 20" MTB which I'm comfortable with, but lots of MTB'ers my height will ride 18" frames. A 6'6" rider with short legs / long torso may be OK with a 21" frame.

It's probably fair to say that as a rule of thumb someone x tall should have a y size frame, but there are so many variables that it's impossible to apply that rule to every person or every bike. Leg length / arm length / tob-tube length, stem and seat post are the obvious variables to consider.

 

[ColinJ]

A 6'6" rider with short legs / long torso may be OK with a 21" frame.

Hmm, I don't know about that ... yes, the legs would be ok (legs are easy to sort out anyway by changing saddle height), but the reach would be way too short unless a stupidly long stem were used. I would suggest such a person should try a 25" frame to suit their long torso, and put the saddle down to suit their short legs!

Ideally, get someone who knows what they are doing to do a proper bike fit.

 

[MattDB]

Was the reasoning for this explained?

No!

 

[MattDB]

Thanks everyone for your help.