Fit question comparing two bikes of different sizes.
12-13-14, 06:19 PM
#1
Senior Member
Thread Starter
Fit question comparing two bikes of different sizes.
I have two road bikes, one a modern Cannondale 58 cm and one a larger 80s Schwinn, size 61cm (both sizes based on seat tube c-c measurement). The Cdale is the right size for me, however, while the Schwinn is on the tall side, both bikes have the same 57.5cm Top tube measurement. The ST angle on the Schwinn is steeper at 74degrees vs. the Cdale's 73. HT angles are also different, 73 for the Schwinn and 73.5 for the Cdale.
So here is the issue. While both bikes are comfortable to ride, they just feel different and I am curious to understand why. I am using a setback seatpost on the Schwinn to compensate for the steeper ST angle, but even though I have same stem length on both bikes, and the saddle to bar drop is about the same (2 inches),when riding the Schwinn I feel like I am positioned out over the handlebars, on the Cdale I feel more centered. I think my saddles are positioned correctly on both bikes relative to the pedals (I.e. Not to far forward on the Schwinn) so I can't figure out what accounts for the sensation I have on the Schwinn of being positioned out over the bars. Is there something about the taller seattube that would account for this even though I have compensated for the steeper angle with the setback post?
So here is the issue. While both bikes are comfortable to ride, they just feel different and I am curious to understand why. I am using a setback seatpost on the Schwinn to compensate for the steeper ST angle, but even though I have same stem length on both bikes, and the saddle to bar drop is about the same (2 inches),when riding the Schwinn I feel like I am positioned out over the handlebars, on the Cdale I feel more centered. I think my saddles are positioned correctly on both bikes relative to the pedals (I.e. Not to far forward on the Schwinn) so I can't figure out what accounts for the sensation I have on the Schwinn of being positioned out over the bars. Is there something about the taller seattube that would account for this even though I have compensated for the steeper angle with the setback post?
12-14-14, 11:06 AM
#2
Banned
Neither can I ... they are just different .. isn't that good enough ?
Measure from a plumb line thru the BB divide the length in 2 .. what do you find?
Measure from a plumb line thru the BB divide the length in 2 .. what do you find?
12-16-14, 01:34 PM
#3
Junior Member
Join Date: Dec 2014
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
If both bikes have the same saddle, measure the setback from the bb center to the nose of the saddle. Measure the seat height to the same place on each saddle. Are the cranks the same length? Measure the bar drop. Measure the bar reach. Check the saddle level angle and make them the same. If everything on each bike is the same then there should not be a problem with fit, if it is correct to begin with. Even then different bikes sometimes have a different feel when ridden. If the saddles are different it is harder because you can be sitting further back or further forward to compensate for saddle differences in shape. Good Luck
12-17-14, 08:54 AM
#4
The Left Coast, USA
Shorter steerer tube-head tube does that for me. All things being equal it still feels like I'm about to jettison off the front.
