which bike size is right?

Question

My girlfriend is just looking for something for a few months to ride to and from Uni. I read that a rule for measurement was to use your inside leg measurement, take off 2inches for a mountain bike, then a further 9... she has a 30.5 inch inside leg and was thinking this would this be the
http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10601_productId_217966_langId_-1_crumb_33980-33957

do you think it's right? or should she be looking for a different size? thanks so much!

Answer 1

There are a lot of different sized frames on the market. Just to make life difficult, different manufactures use different methods to measure them.
In this case the 19.5 "would be a centre to top measurement(c-t)
(centre of bottom bracket(pedal crank) to top of the frame at seatpost)
Any thing close to this will fit her. Manufactures usually step their frames in about 1"-1.5" increments. If they don't have one within half an inch of the 19.5 then;
If she is proportionally shorter in the leg go for the size above. If she has lovely long legs go the one below.
There is plenty of adjustment in the seat post to match up leg length. The larger frame will also be longer to the handle bars. This suits people with a longer trunk section.
The seat height should be adjusted so that the leg can be just straightened with the ankle bent (toes up). If the pelvis rocks the seat is to high. Make sure she has a ladies Saddle (their pelvic bones are wider)
Handle bars can be wherever she wants for comfort or speed.

To clarify we are talking standard road bike hear. Probably the best choice to ride to and from uni.
Mountain bike geometry is much different,

Answer 2

The general rule of thumb for a right sizing is that when straddling the bike with both feet on the ground that your crotch should be at least one inch above the tube(bar that runs from your handlebars to your seat). Now a woman's bike usually has a sloping tube from the bars to the seat, so what she should do is go to wal-mart or wherever and sit on a few guys mountain bikes 22, 24 26" etc. and see which one is the closest to being 1" away from her, crotch. then go with the same size bike in a woman's model. Adjustments can be made to the bike so that her knees are slightly bent on the downward stroke of the pedal, adjust the bars so that the spine is tilted forward but in a comfortable position when sitting on the seat and holding the handgrips. Feel free to ask any more questions.

Answer 3

Go with her to a pecialized store. Different kind of bikes and different brands have different frames. A rule lf thumb is that there should be about 4 inches between the top tube of the frame and the crotch when standing in the bike with ur feet on the ground. Nevertheless as i told u different bikes will have a different frame shape so it will change, so go to ta specialized strre pick one andask the people there the best size and TRY the bike. I'm 1.71m tall and ride a 17 inch mtb.

Answer 4

I would be careful when selecting a bicycle for your girlfriend. The old rule of standover height is highly inaccurate given the modern changes in frame geometry (top tubes that run on an angle, as opposed to horizontal) It is far more important that the reach to the handlebar(she should be able to reach it easily and have a gentle bend in the elbows without hunching her back), and the height of the handlebar in relation to the seat height (generally unless you are racing, your hands should be higher than your seat) are comfortable for her. The best way to determine this is to have her sit on several bikes, and choose the best one. I am 5'4" tall and I ride about a 50cm road bike. I hope you find this helpful.

Answer 5

How tall are you and what's your inseam? in good shape on a bicycle is each and everything. whilst a sky extreme seat posts are available in, a too small physique places the handlebars very low. i grew to become into talked into procuring a 23" Cannondale years in the past through a mind-blowing bike save. against my better judgement, yet I did verify in the dotted line. After using the bike for some days I knew the physique grew to become into too small. Very uncomfortable to journey. Handlebars too low. After lots haggling with the bike save and Cannondale, I swapped 23" physique for a 24.5" physique. lots greater gentle. in the previous you verify in the dotted line verify you have the final length physique on your top, leg length and foot length. good success

Answer 6

Your measurement is wrong. That sounds more like a crude seat height setting. You should look at wrenchscience and take a few measurements to find her perfect fit.

Go to http://www.wrenchscience.com/Store.aspx?stylecode=M and choose "fit system" from the top. Go ahead and register- they don't mess with your info and I have NEVER been put on a spam list from them.

Answer 7

if you're measuring her in stocking feet from the floor to where a 1.5" thick book snugged up good in to her crotch then - 30.5" =

road frame size is 51cm or small - perhaps extra small
seat height from center of crank bolt to top of saddle cradle is 68.4cm

Answer 8

Generally, when your pedal is at the bottom of the downstroke, your knee should be slightly bent. Any good bike shop in your area will be able to help you with no trouble.