Hybrid Bicycles - Did the store sell me the right hybrid size?

Hi,

I saw some nice specials yesterday on hybrids in a sport store. I asked a clerk to help me choose the right bike for me and I settled for a local brand, a Louis Garneau Excusion for 280$ cdn:

http://www.louisgarneau.com/catalogs/catalog_product.asp?catalogue=BI9&section=HY&sub_section=011&style_no=9302027&type_catalogue=&language=ENG&website=1


The store clerk recommended me a small (42cm, 16.53in) frame, which I tough was too small for me (i'm 5'65) but the clerk assured me that this was the right size. Here the frame chart : http://www.louisgarneau.com/media/images/common/catalogs/geometry/2009/BI9_HY_011.jpg

What do you think about this? Was he right about the frame size? I tried it just a little around home and he seemed that I needed to put the saddle pretty high for confort, but since this is my first hybrid I don't know if this is normal.

Thank you in advance!

the way that is measured is somewhat odd, if you run a string from the headset to the seat post and parallel to the ground and then measured from the bottom bracket to the string, what is the numbers?

This would be a more accurate measurement of the frame size. The exagerated slopes on the top tubes make the frames seem extremely small.

So the answer is, I can't tell you without seeing how have been fit on the bike. The salesperson did fit you on your new bike right? If not get the to a lbs.

Don't worry about having to put the seat up high as long as you leave the minimum amount of seatpost in the frame. The seatpost will have a minimum insertion mark on it. If you can get your seat the proper distance from your pedals and you can get your handlebars where you want them relative to the saddle, the frame size doesn't really matter that much. This bike is probably a size or two small for me. I replaced the stock seatpost with a longer one to make it fit.http://i478.photobucket.com/albums/rr147/Rod_Smith/IMG_2681.jpg

First thanks in advance for your answers!


Here's the measurement from the headset to the seat post : 22in

For the other measurement, I know what's a bottom bracket, but for the "string" what do you mean?

I have a 19", but it also has a parallel to the ground top tube. About 1/2" crotch to tube, mostly because I've shrunk a tad since I got the bike (18 years ago). That old chestnut doesn't work much anymore because of the large slope in today's top tubes.

So I'm thinking it's more about the amount of seatpost visible from the top of the seat tube. Something tells me about 6 inches should be just about right... am curious about how others think/feel about this way of sizing a frame?

First thanks in advance for your answers!


Here's the measurement from the headset to the seat post : 22in

For the other measurement, I know what's a bottom bracket, but for the "string" what do you mean?

The size of a bike is traditiionally measured from the center of the bottom bracket to the center of the top tube where it connects with the seat tube. In the case of bikes with sloping top tubes like yours, the size is usually measured from the center of BB to center of an imaginary top tube (represented by the string) level to the ground. This allows bikes with sloping top tubes to be compared to bikes with level top tubes. Measure the (virtual) top tube length along the string also. Your bike is a 16.5". A rule of thumb is your inseam minus 13". So if your inseam is in around 29-30 inches, you should be able to get a good fit on this frame.

First thanks in advance for your answers!


Here's the measurement from the headset to the seat post : 22in

For the other measurement, I know what's a bottom bracket, but for the "string" what do you mean?


if you run a string from the headset to the seat post and parallel to the ground and then measured from the bottom bracket to the string, what is the numbers?

This would be a more accurate measurement of the frame size. The exagerated slopes on the top tubes make the frames seem extremely small.

The salesperson did fit you on your new bike right? If not get the to a lbs.

With the exagerated slopes of many modern frames it becomes difficult to measure sizes. If a string is stretched from the head tube to the seat post, running parrallel to the ground, then you will be able to better estimate the real size of your frame.

I have a 19", but it also has a parallel to the ground top tube. About 1/2" crotch to tube, mostly because I've shrunk a tad since I got the bike (18 years ago). That old chestnut doesn't work much anymore because of the large slope in today's top tubes.

So I'm thinking it's more about the amount of seatpost visible from the top of the seat tube. Something tells me about 6 inches should be just about right... am curious about how others think/feel about this way of sizing a frame?

I like the rule of thumb that the amount of seat tube showing should be about the same as the height of the head tube, but the varying degrees of top tube slope that you allude to in your post makes looking at how much seatpost is sticking out to be of little value.

I realized that the Large size (20") trek fx 7.2 that my shop sold me was a tad too small! good thing i sold it a couple of days ago. i sat on a 7.3 fx in an XL yesterday and man that felt so much better!

My inseam is 29inch.

And the measurement from the headset to the seat post , parallel to the ground is 21in (not 22 like I stated in my other post)

29inch, sounds good! Like I said, as long as the minimum insertion mark on your seatpost is in the frame, you don't have to worry about how high it looks. Obviously, with a steeply sloped top tube like yours, more seatpost will be showing compared to a more traditional shaped frame (level top tube) set up to fit the same rider.

29 inseam, a 16" frame is a good size to spin on.
An 18" inch frame may cause your legs to pronate or stretch and you
won't spin as fast cause your stretching on the downstroke.
The lbs may have a kit to lengthen the reach from your stem to the bars.
I'm guessing you probably have a 21 or 22" spine.

As long as you are comfortable pedalling, and comfortable with the reach to the bars, frame size doesn't matter.

I ilke to be stretched out when riding; but, everyone isn't like me.....

It's really your comfort that matters...

By the way - I'd get rid of that suspension seatpost. They are wiggly, and steal energy really, really, well.

I
m 5'8.5" and was sold an 18" hybrid. I'm also a girl. Even I am supposed to have the seat almost creepily high. I currently have the seat a bit too low, I've crashed twice so being up so high makes me nervous. I'm working on getting past that problem. Having the seat too LOW is murder on your knees.

29 inseam, a 16" frame is a good size to spin on.
An 18" inch frame may cause your legs to pronate or stretch and you
won't spin as fast cause your stretching on the downstroke.
The lbs may have a kit to lengthen the reach from your stem to the bars.
I'm guessing you probably have a 21 or 22" spine.

Yes, 16 on a bike like this is about right. My leg is a 31 and I ride a 17'' MTB. *If* arm reach or drop are a problem, fit a higher and shorter stem.

Most non-enthusiast cyclists have bikes with saddles that are set much too low - this destroys pedaling efficiency and can mess up the knees. If the height really saddle bothers you, mark the current position and gradually build back up to it from a height halfway between what you think is right and the one the store sugested.

I
m 5'8.5" and was sold an 18" hybrid. I'm also a girl. Even I am supposed to have the seat almost creepily high. I currently have the seat a bit too low, I've crashed twice so being up so high makes me nervous. I'm working on getting past that problem. Having the seat too LOW is murder on your knees.

I don't normally say this, but it sounds like you should wear a helmet. The $20 Walmart ones are just as safe as the $200 - i.e. they'll help if you have a simple wobble. The main thing is to be fussy about fit and follow the instructions about how to wear it *exactly*. Cycling gloves might be a nice idea too.

An 18'' hybrid sounds like it might be too big. This would result in too far a reach, messing up bike handling and risking neck and back strain. But a lot depends on the exact design of the bike. Look at eg

www.bonthronebikes.co.uk/help/bike-frame-size-advice-guide

If you feel the size might be wrong, go back and have words with the store manager. Take a witness. In the UK I'd probably be able to make quite a fuss and probably get the bike changed for a minimal fee if it was only a few months old - after a big battle - but I'm an expert in being a pain, and UK law is excellent if you know how to use it. Get someone who knows what they are doing to look at you on the bike and/or try out a smaller model. If you have to, sell your bike and buy a used one that fits.

I
m 5'8.5" and was sold an 18" hybrid. I'm also a girl. Even I am supposed to have the seat almost creepily high. I currently have the seat a bit too low, I've crashed twice so being up so high makes me nervous. I'm working on getting past that problem. Having the seat too LOW is murder on your knees.

Assuming you don't have un usually long or short legs, that sounds about right. Yes, it generally should be that you get on the seat once you stand on one of the pegs. Many people seem to think they have to put flat feet on the ground sitting on the saddle... way wrong. On the seat, shoeless, your heel should rest on the peddle with your leg straight. Take a look at the amount of seat post showing above the seat tube... I'd almost bet if you had the seat perfect in height, you'd see 6-7 inches. When I see over a foot, I think "way too short bike," when I see almost no seat tube I think "way too tall bike."

Try and keep repeating to yourself... "once I'm going, things will be smooth."

You need that leg extension to get all the power that is in your legs.

"meanwhile", Luddite knows her bike fits and she knows how to adjust her helmet straps.

If her seatpost has to be "creepily high" to get good extension, I doubt the bike is too big. Concerning the helmet, we have photographic evidence that she wears it well.

Assuming you don't have un usually long or short legs, that sounds about right. Yes, it generally should be that you get on the seat once you stand on one of the pegs. Many people seem to think they have to put flat feet on the ground sitting on the saddle... way wrong. On the seat, shoeless, your heel should rest on the peddle with your leg straight. Take a look at the amount of seat post showing above the seat tube... I'd almost bet if you had the seat perfect in height, you'd see 6-7 inches. When I see over a foot, I think "way too short bike," when I see almost no seat tube I think "way too tall bike."

Try and keep repeating to yourself... "once I'm going, things will be smooth."

You need that leg extension to get all the power that is in your legs.

I have a 31" inseam, I think. The bike is the right size for me, I mean it feels quite comfortable to ride. I don't totally straighten out my leg on the downstroke, the LBS guy told me the seat is too low and I''ll "blow out my knees." I don't have a quick release seat so I have to take it to him to get it adjusted and well, with the stress of getting ready for college I keep putting that on the backburner, I also need my rear brake adjusted. I really have to do something about it THIS weekend.

"meanwhile", Luddite knows her bike fits and she knows how to adjust her helmet straps.

If her seatpost has to be "creepily high" to get good extension, I doubt the bike is too big. Concerning the helmet, we have photographic evidence that she wears it well.

I frequently have the chin strap too loose. I hate wearing it tight, plus today I totally forgot it cause I was running late for work.

The two times I crashed I was wearing a helmet, though my head didn't go near the ground in the first crash, the second one I only slightly scuffed my helmet.

My first crash shifted the seat down a bit, the LBS guy was observant enough to notice that when I went there for another reason. Having it back to the right height freaked me out. It wasn't a bad or high speed crash, either, though I jammed my shoulder falling and it was messed up for a bit. Second crash was worse but I'm desensitized to crashing now. :roflmao2: