Bike Frame size

lamai

I do triathlons, and use a road bike with tri bars attached. Been using it for about 3 years now, but just recently I measured the frame size and it is 50cm. My height is 5' 9". looking briefly as sizing charts it says that I should be on a 56cm frame. I have struggled alot with my bike, compared to my running. Would the right frame size make much of a difference in Time trials, duathlons and triathlons?

thanks

Vélo

What make is your bike?

A 50cm bike sounds way too small but the frame could have relaxed geometery. I'm 5' 7" and had a Giant SCR C3 before that was 50cm (Relaxed geometery), I got rid of it as I thought it was a little too big. If I remember correctly the correct size for the bike I had was 5' 7" - 5' 10".

lamai

Vélo wrote: »

What make is your bike?

A 50cm bike sounds way too small but the frame could have relaxed geometery. I'm 5' 7" and had a Giant SCR C3 before that was 50cm (Relaxed geometery), I got rid of it as I thought it was a little too big. If I remember correctly the correct size for the bike I had was 5' 7" - 5' 10".

It's a Giant scr 4 2007 model

petethedrummer

I'm 5'10 ish and ride a M or 50cm SCR. Because of the very sloping top tube, the seat tube measurement is quite small. If it was a traditional non sloping top tube, it would probably be a 55cm bike. Which would be about right for someone 5'9.

There should be a sticker near the bottom of the down tube which will tell you what size rider your bike suits. Mine says 5'7 to 5'11.

crashoveroid

If you want to get sized for a bike go to your LBS and get them to help you im 5'11 and i need a 53cm frame but all the guides say i should be on a 56 as well.

Lemag

I don't know much/anything about time trialing but don't suitable timetrial bikes tend to be sized small than road bikes. If so, that the OP is using a road bike for time trialing, is it not perhaps quite suitable that his bike would be classed as a little too small for him for "normal" road use?

lamai

petethedrummer wrote: »

I'm 5'10 ish and ride a M or 50cm SCR. Because of the very sloping top tube, the seat tube measurement is quite small. If it was a traditional non sloping top tube, it would probably be a 55cm bike. Which would be about right for someone 5'9.

There should be a sticker near the bottom of the down tube which will tell you what size rider your bike suits. Mine says 5'7 to 5'11.

damn need to find another excuse then why I am so crap on the bike:mad:

petethedrummer

lamai wrote: »

damn need to find another excuse then why I am so crap on the bike:mad:

Could be your position.

Actually I have a mate who does triathlons and he says the cycling is his weakest part....Its because he doesn't do much cycling. Do you do much cycling?

Single Malt

Also, road sizing is not suitable for tri. Frames need to be smaller, as they need to be shorter for the aero tuck on the bars. I am 5'11" and would use a 53 cm top tube for a tt bike, while a 56cm on my road bike. Also do yoga or pilates, as flexibility is hugely important for a good tri position. Your bad performances on the bike are likely lack of km or wrong bike position.