Bike sizing.

[Onthedrops]

Currently ride a 54 cm bike.
Had a good browse round a good bike shop today and tried out a couple. Obviously selected a Medium framed example. Stand over felt comfortable. Took bike outside and had a little poodle around. Imagine my surprise when the bike shop guy informed me that the bike I was riding looked just a wee bit too big for me. He said I looked to be stretching slightly for the hoods. He then got out a small framed bike for me to try (Giant Advanced) I wasn't convinced. Had a ride round on it and have to say that the comfort level was far superior. The bike felt great. I did notice though that on the medium frame that the stem was slightly longer and the bars slightly wider.

My initial thought was to ask about putting a shorter stem and more compact bars on it. Would this be a good idea? Or am I better off opting for the smaller frame?
It did have more saddle stem visible, which would possibly aid comfort owing to the flex available. This indecisiveness prevented me from ordering.

My question. Is it better to ride a smaller bike than one which may just be slightly too large?

 

[Cyclist33]

Currently ride a 54 cm bike.
Had a good browse round a good bike shop today and tried out a couple. Obviously selected a Medium framed example. Stand over felt comfortable. Took bike outside and had a little poodle around. Imagine my surprise when the bike shop guy informed me that the bike I was riding looked just a wee bit too big for me. He said I looked to be stretching slightly for the hoods. He then got out a small framed bike for me to try (Giant Advanced) I wasn't convinced. Had a ride round on it and have to say that the comfort level was far superior. The bike felt great. I did notice though that on the medium frame that the stem was slightly longer and the bars slightly wider.

My initial thought was to ask about putting a shorter stem and more compact bars on it. Would this be a good idea? Or am I better off opting for the smaller frame?
It did have more saddle stem visible, which would possibly aid comfort owing to the flex available. This indecisiveness prevented me from ordering.

My question. Is it better to ride a smaller bike than one which may just be slightly too large?

Opinion is divided on that one. My take is that unless the bike is wildly the wrong size, it doesn't matter as things like stem seat post etc can be adjusted or swapped to fit you.

My other opinion on the matter is that people too often get a smaller bike because it initially feels more comfortable, but actually a slightly bigger bike gives your body more room and let's you stretch out more, in the long run this is better for you. Unfortunately too many of us are content to waddle around and pick short, upright road bikes that flatter our anatomical laziness.

 

[Milkfloat]

IMO Giants come up a little big anyway, so comparing to your existing bike is pointless. In fact what the stickers says is irrelevant on all bikes, what fits is key. Secondly, it is easier to make a slightly too small bike bigger, than it is to make a too big bike smaller.

 

[Cyclist33]

IMO Giants come up a little big anyway, so comparing to your existing bike is pointless. In fact what the stickers says is irrelevant on all bikes, what fits is key. Secondly, it is easier to make a slightly too small bike bigger, than it is to make a too big bike smaller.

Where did you read that?

For fairness you should be saying "a slightly too big bike" and it simply ain't true, component or fit adjustments go either way. Besides that, it is better for a human body to adapt by stretching slightly than by making it more hunched up.

 

[Illaveago]

Does an enormous seat post protruding from the frame have an adverse effect on the handling?

 

[Cyclist33]

Does an enormous seat post protruding from the frame have an adverse effect on the handling?

If anything it would improve it, assuming it was needed for the correct fit, but anyway I thought the scenario was the rider in between two sizes, if so then we're only talking about a cm or two difference in visible seat post length.

 

[Milkfloat]

Where did you read that?

For fairness you should be saying "a slightly too big bike" and it simply ain't true, component or fit adjustments go either way. Besides that, it is better for a human body to adapt by stretching slightly than by making it more hunched up.

My bike fitter, any LBS I have broached the subject with and by far the majority of 'internet wisdom' I have read all suggest that if you are borderline, then go for the smaller frame. IMO there is more of a limit in putting on shorter stems and dropping posts than there is to go the other way. I would also prefer slightly too short crank arms, than too long.

Fair point about adding 'slightly too' for the big bike, that was just trying to avoid typing too much on my iPad.

 

[Cyclist33]

That is really the key word here though. If you're bike is a gnats wing on the small side you could for example put an extra cm on the stem. Likewise reduce by a cm if bike slightly too big. Of course there are only so many centimetres of shortening you can do compared to a theoretical infinite amount of lengthening, but again this isn't about making an XS bike fit a 6'5" person or getting a 5 footer onto an XL.

Probably I should just be advising the OP not to get either bike and go look for that fits first time round!

 

[Milkfloat]

Probably I should just be advising the OP not to get either bike and go look for that fits first time round!

100% agree, there are enough bikes out there for you to find one that is perfect. Only resort to messing with stems, new bars etc if your body changes or you end up with the wrong bike and need to try and fix it.

 

[ayceejay]

The measurement you should be looking at on a bike with a sloping top tube is what Americans call 'stack' which is more or less the equivalent to regular sizing therefore the Small size in the bike you are looking at has a stack of 54.5 and the Medium is 56.6..

 

[Onthedrops]

To be fair, looking at the size guide on the Giant website, my measurements would put me on a small frame.

Would it be wise to suggest getting a fitting before pulling the trigger and buying? Would this be part of the buying process? Never had this luxury with my first bike. More of a case of roll up, stand over test then the guy said " you'll be good with that one"

 

[Bicykell]

Well.....
Being 5ft 7" with a 29" leg I was having difficulty with small - 51/52 cm frames. I found that on various bikes including the Giant Advanced I was not comfortable as the frame length seemed too short. I bought a medium Look 566 after a lot of prevarication and have had no regrets about its comfort.

So I would advocate trying different bikes and tormenting the sales staff until you find the bike that says "It's me."

 

[vickster]

To be fair, looking at the size guide on the Giant website, my measurements would put me on a small frame.

Would it be wise to suggest getting a fitting before pulling the trigger and buying? Would this be part of the buying process? Never had this luxury with my first bike. More of a case of roll up, stand over test then the guy said " you'll be good with that one"

Yes, go to some shops, sit on a few, buy the bike that is the one from the shop where you try it out where in the country are you, a giant shop will have all of the models in at least one of the frame sizes

If a small one feels best, why would you then get a medium one and then spend more money changing stuff?

 

[Onthedrops]

Yes, go to some shops, sit on a few, buy the bike that is the one from the shop where you try it out where in the country are you, a giant shop will have all of the models in at least one of the frame sizes

If a small one feels best, why would you the. get a medium one and then spend more money changing stuff?

Good point well made.
I had a run down to the Sheffield store last week. Just one XL framed example in store.
Contemplated a run out to the York store but found a good shop with a fair few Giants in stock more locally (West Yorks)
Played on the Advanced 3 which is Tiagra kitted. Same frame and set up as the Advanced 2 so got a fair idea.
The new 'uns come out over the coming week or two. Liking the frame colour of the new one, plus it has an 11/32 cassette on the 2016 model.

 

[vickster]

Compare the geometries, then go back to the shop