luciddiscord

Hello:

I am in the market for a new bike. My riding style is 20-50 mile rides for health and fitness and keeping up with the occassional 16-20 mph club ride. I am not a racer and prefer comfort over speed.
I currently ride a trek 2.3 56cm compact and it has always felt a little small.

I am 5'11", 175 lbs, with a PBH of 34.5 inches (87.6 cm). According to the lemond formula using 0.65 or 0.67 gives a range of frame sizes between 57-59 cm. Rivendell method would suggest a frame size around 60 cm.

My input into competitive cyclist is:


And my output from competitive cyclist is:


It seems like my legs are a little on the long side for my height. As a result the calculations suggest a top tube around 56 cm and a seat tube around 58 cm. So, I have alot of data, and I am trying to figure out what it means.

My Questions: Should I prioritize top tube or seat tube when choosing a frame size? Does anyone have measurements similiar to mine, what do you ride?

Thanks!!

luciddiscord

Bump. Help!

Dfrost 

If you really "prefer comfort over speed" then be cautious about selecting a smaller frame, because that typically results in greater drop from the saddle to the bars. 56cm does sound small for someone with your inseam length. Rivendell's fit tends to be a little bit long in the TT, and his frames often have a lower BB.

See other posts in this sub forum about bike fitting with long legs.

Kopsis

If you want a second (or third) opinion, there's always the Dave Moulton method: https://www.davemoultonregistry.com/M...FrameSizeChart

ThermionicScott 

Note that the Competitive Cyclist output assumes a 104-110mm stem for the Eddy fit. When going for more of that "big-frame" fit, you may wind up with a shorter stem than commonly used.

luciddiscord

So if competitive cyclist is recommending a 56 cm top tube. I could get a 58 cm top tube and just back 20 mm off of my stem? Are there any issues with doing that?

Thanks!

Leisesturm

Did you take all of your measurements three times and average the results as is recommended? I'm not accusing, I'm just asking. 1/2" of error can throw complex formulas like they use in the CC fit calculator wildly off track. I am in your general area of height. IMO what you should be doing with the CC calculator is working with the French Fit criteria and then you won't have to second guess the results as much. Two of my bikes have 59cm top tubes, they were 'buy now, ask questions later great deals'. I have swapped out the 110mm stems they came with for 90mm stems. Theoretically, this should quicken the steering and make the bikes less stable. In practice, I doubt the difference can be perceived. Going to a 50mm or 60mm maybe but not to 90mm. FWIW.

H

ThermionicScott 

No real issues that I can think of. I use 80-100mm stems on my bikes, depending on the frame size and setup. (I don't set up all my bikes to fit the same way.)