Road Bike Sizing

Mairead Lacey

Hi Folks, hope some of you might be able to help me, I'm trying to buy my first road bike and like the Trek Lexa SL. I've found a good deal on one but its a 47cm frame which I think is too small for me. The guy in the shops says its fine but I'm not so sure, he wants to sell the bike at the end of the day! I'm 5ft 5 so I think i'd need a 52-54 cm frame?

coastwatch

I think you're right, a 47cm frame would be too small for someone 5'5". It might be look like a good deal but it wont feel like one.
I think you would need a 50" - 52" frame, a 54" would be too big.

I'd be inclined to look elsewhere, try other shops and similar bikes and see what size they are recommending.

petethedrummer

It depends on the brand. A 47 in one brand may mean something else in another brand. A small in a Giant avail is a 46.5, their XS is 43.0.
http://www.giant-bicycles.com/es-us/bikes/model/avail.1.navy.blue.white.silver/7306/44117/

The most important thing though is how it feels when you're on it. What sort of bike is it?

rainbow kirby

I'm 1 inch taller than you and have a Trek Lexa S - a 52cm frame is perfect for me, 47cm is for midgets.

tech

I had the same issue lately, before I boughy my bike, Im 5" 8" and was been sold a 55, but was in another shop and they had both size frames and sat me on bith and the 52 was a nicer fit for me, alot fo shops will do anything just to sell what they have in sotck which is very un fair.

pgd-pgd

Heres some links here might help. Its not just your overall height you need to consider inside leg measurement as well


This 1st link shows classic and sloping top tubes reference heights.

http://www.cyclesuperstore.ie/shop/pc/viewContent.asp?idpage=40

http://www.ebicycles.com/custom/content_files/ebicycles-bicycle-sizing-chart-road-bikes.pdf

MaroonTam

pgd-pgd wrote: »

http://www.ebicycles.com/custom/content_files/ebicycles-bicycle-sizing-chart-road-bikes.pdf

My frame would be on the bigger end of the scale quoted here, but my proportions are more for a longer upper body in relation to my legs, so the reach was a more important consideration than inside leg.

Mairead Lacey

Thanks for the advice guys, very helpful, its a Trek Lexa SL Pete. Going bicycle shopping again tomorrow, the search continues but hope to put an end to it tomorrow

petethedrummer

http://www.trekbikes.com/uk/en/model/fit_sizing?url=uk/en/bikes/road/sport/lexa/lexa_sl

Trek* have standard enough sizing, so a 47 is too small for you at 5'5". It would be a matter of taking a 50 and 52 for a spin and seeing which one you prefer.

(*Lappiere and Giant have misleading sizing.)

Caroline_ie

rainbow kirby wrote: »

47cm is for midgets.

I have a Trek in sz 43.
Why am I slightly offended by this?

Mairead Lacey

Hi guys, still on the hunt strongly considering buying this bike but struggling to find recent reviews on it, does any have it? Or check out this link and let me know what your thoughts are on it.http://www.claudbutler.co.uk/Corporate/CB/Vicenza.shtml

Thanks

M

coastwatch

The bike looks ok, I'm not too familiar with current Claud Butler bikes.
The geometry / sizing is a bit confusing though, the top tube length is the same for both 50 & 53 frames.

The most important dimension to get right in sizing a road bike is the Top Tube Length, sometimes called "horizontal" Top Tube Length or Effective Top Tube Length (or Cockpit length on the C Butler website). If it's too long, you'll feel "stretched" and uncomfortable, too short and you'll be too upright. The sizing can be altered by changing the stem to a shorter / longer one, but it's better to get the frame as close to right as possible. The Seat Tube length is less important because the saddle is raised or lowered to suit. According to the geometry in the link, the top tube length for a 50 & 53 frame is 549mm which seems too big for you, as mentioned earlier in the thread, you would need a frame with a frame size (top tube length) around 51 -53, which isn't available in that model.

Also, the 2012 Tiagra groupset is 10 speed, instead of the current 9. Not a big deal, but I think "more is better" when it comes to gears. The new cassette is 12-30 instead of 11-25 on the CB bike, so more "easier" gears for going up hills if you like doing that.

joconnell

I'm an utter newb to this but this seems to make sense:

https://www.youtube.com/watch?v=1Fsr7yYShD8

tech

looks good !

pgd-pgd

Another good link here about setup

http://www.bikedynamics.co.uk/guidelines.htm