Road Bike, Cycling Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
82 Posts
Discussion Starter #1 (Edited)
Fit: 54 or 56 cm R5000?

I rode last year on a 56 cm cannondale with a 100 mm stem and the seat moved pretty much all the way forward. I'm 5'10" with a 80.8 cm inseam. I paid for a fitting at one of Boston's best bike shops.

Measuring myself tonight (probably not too reliable) for the Flyte system I get 66 cm for torso length, and an arm extension of 64 cm. By this system I should get a bike that is 54.1 cm (they don't say which measurement this is) with a 115 mm stem. This is pretty close to what I have now. When I go into random bike shops and get the casual eyeball method size recommendations from the workers they always say I could go with either a 56 or 54.

I was bothered by my stem size when I started racing. It seems most racers are using 110 or 120 cm stems, so I started thinking my bike was too big for me. The 56 cm Cannondales have a top tube length of 56 cm, and the 54 cm bikes have a top tube length of 54.5.

It's time to order a new bike and I'm wondering if I should get the smaller bike and put on a longer stem. It's only 15 mm shorter and this could easily be made up with a longer stem and moving the seat back some.

Isn't it better to have a bike that is a tad small rather than too big for racing crits and shorter road races? I think I became comfortable being stretched on the bike and my coach thinks I should get more aero. Putting a longer stem on my 56cm could do this, but the seat is still very forward (KOPS appropriate). To get more aero on the 54 would mean getting a longer stem and moving the seat back some, and I'm not sure if this would change the muscle groups I use adversely or give me more power. Do you lose power if your seat is too far forward?

I got to ride a 54 cm Six13 for a week and it felt alright, but it was hardly a controlled experiment as just about everything was different about this bike compared to my R700. The stem was 110 mm, and overall it felt smaller.

What would you do? I'm sticking with Cannondale as we get deals on them. I have till Friday to get my team order in....

Pictures of me on the bike: http://www.garyjaz.com/r700/index_r700.html

-g

*I would get the 55 cm bike but cannondale only offers this size in their very expensive team ones this year. I have searched for an older aluminum 55 all winter to no avail.
** Geometry here: http://www.cannondale.com/bikes/06/geo-613.html
 

·
Registered
Joined
·
164 Posts
try different bike brands

Looks like you have a long torso for your height and short femurs. So look for a bike with a long top tub and seat tube angle of 73 or 74. Look around at differnt brands. I would say 56 if you stay with Cdale. A 15 stem is silly on a 54. Look at trek. Their bikes are long. I think Felt also makes long bikes.

A 10 cm stem is fine. Don't worry about whether other people have an 11 or 12. Just fit the bike to you.

Good luck!
 

·
Registered
Joined
·
147 Posts
Have you considered rolling your handlebars forward and then raise the shifters a little higher. I ride the same bike in the same size and it made a huge difference to me.
 

·
Registered
Joined
·
220 Posts
I think there is an error with the 15 cm stem comment. If you need a 10 cm stem on a 56, then you would need an 11.5 cm on the 54. The math is a pretty straight forward since thet seat angle between the two bikes are the same. I'm your size and I went with a 54 last year and used an 11 cm stem so I don't believe its too odd, however I do need a bit more spacers than I would like. Flipping the stem is always an option. I felt the 56 was a bit big for me especially since the seat angle is the same as a 54 making the TT longer. I also prefer to sit a bit back on the seat. If I did it again, I may go with the 55 since I'm looking for a bit longer wheelbase. Head tube is the same between a 54 and 55 so your not giving up anything there.
 

·
Registered
Joined
·
82 Posts
Discussion Starter #5 (Edited)
Well this is an interesting post. I thought I must be shorter in the torso for my height since my coach is 2 inches taller and yet the height of his seat is just a bit larger than mine.

I meant 11.5 cm, not 15. My bad. Maybe this typo is what you are basing this opinion on. I think most who have responded have voted for the 54 (I posted the same question to the general discussion group and have about 15 responses over there).

After getting a fitting at the shop that we get our bikes from a few days ago, I ordered a 54 and can't wait to get it.



Coot72 said:
Looks like you have a long torso for your height and short femurs. So look for a bike with a long top tub and seat tube angle of 73 or 74. Look around at differnt brands. I would say 56 if you stay with Cdale. A 15 stem is silly on a 54. Look at trek. Their bikes are long. I think Felt also makes long bikes.

A 10 cm stem is fine. Don't worry about whether other people have an 11 or 12. Just fit the bike to you.

Good luck!
:D
 

·
Registered
Joined
·
164 Posts
Makes more sense

GaryJaz said:
Well this is an interesting post. I thought I must be shorter in the torso for my height since my coach is 2 inches taller and yet the height of his seat is just a bit larger than mine.

I meant 11.5 cm, not 15. My bad. Maybe this typo is what you are basing this opinion on. I think most who have responded have voted for the 54 (I posted the same question to the general discussion group and have about 15 responses over there).

After getting a fitting at the shop that we get our bikes from a few days ago, I ordered a 54 and can't wait to get it.




:D

150 stem is just crazy! It makes more sense now. Good luck with the 54. My sense is that it is a bit small, but it might work for you. You can always flip the stem and so forth. Enjoy your ride and post a ride report after you get it built up. Happy riding!!

C72
 
1 - 6 of 6 Posts
Top