dsonyay

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I'm comparing two frames. Both are Nashbar bikes: the Carbon 105 and the CR4 Carbon Road Bike. At first I thought both bikes used the same frame, but they are different.

I looked at frame geometry and here are the specs:


Frame size 50cm........105 -------------CR4

Effective Top Tube....530mm....533.6mm
Seat tube....................500mm....500 mm
Seat tube angle..........74.5...........74
Head tube angle.........72.5.......... 72
Headtube lgth............125mm......130mm
BB drop.......................68mm........68mm
Chainstay..................405mm.......407mm
Wheelbase.................975mm.......980mm

BB size.......................BB86........BB30

Based on these measurements alone, are both basically the same, or would one seemed more aggressive or race oriented over the other? Or is this not enough info base anything off of?

I assume stiffness and build quality play a big part as well.


Here are links to the bikes:
Nashbar CR4 Carbon Road Bike - 11 Speed Ultegra

Nashbar Carbon 105 Road Bike

JohnDThompson 

The CR4 is a little more relaxed than the 105, but not dramatically so. If you plan to race criteriums, the 105 might be more suitable.

dsonyay

That was my guess. The CR4 seems to be advertised as their all out race oriented bike over the 105. But the shorter wheel base and other measurements seemed to point to the 105 as the more race oriented frame.

I prefer the 105 mostly because I'm more of a novice biker and my biking is mostly done to burn calories. I dont think I really need to go up to the Ultegra gear at the moment. Although I'm slowly getting more serious about racing and starting to look at tri events.

I workout with friends who compete, so having a good bike for 15 to 20 mile spirited rides is a plus. I really enjoy biking, and coupled with running, it really has me burning calories and getting in good cardio shape.

I'm looking for a good bike of my own. I've been using a Trek 1.1 for a long time. Loaned to me by my brother in law who has quite a few. It's his first road bike. I rode on his Madone 4.3 also, and it was not much different than the aluminum framed Trek. But I'm fairly new to all this, so at this point I can't tell much.

Thanks!

Garfield Cat

Not enough information because of "stack" and "reach".

Bike Geometry, Sizing and Fit - Cervélo

JohnDThompson 

It depends what kind of race. Criteriums like steep, tightly coupled frames for maneuverability. Stage races and endurance events like triathlons sacrifice a little maneuverability for long-term comfort in the saddle.

TheManShow

Longer wheel base = comfort.

JohnDThompson 

Sure, but there's only 5mm difference in the frames the OP is considering.

Blue Belly

Thats a pretty extreme seat tube angle & a relaxed head tube. The stays are short. Almost Time Trial geometry. Maybe its fast but, I can't imagine it being too comfortable, or handle too sharply.

JohnDThompson 

No, those angles are chosen to reduce toe overlap on a 50cm frame using 700C wheels without requiring an excessively long top tube. An arguably better solution would be to use smaller wheels, e.g. 650B (584mm ERD) or even 650C (571mm ERD), but these are less commonly stocked by shops and require the manufacturer to stock special wheels and tires for their smaller frame sizes.

If you look on the "Sizing Chart" on the links the OP provides, you'll see that the larger frame sizes have steeper head tubes and slacker seat tubes because toe overlap is less of a concern with those sizes.

dsonyay

Great information! Thanks...