Sizing help!
10-19-11 | 11:52 AM
#1
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Sizing help!
I had a road bike years ago but got out of the sport, and am now getting back in.
My fit measurements are as follows, in inches:
I have settled on a bike with the following geometry:
Unfortunately I don't have the luxury of many knowledgeable LBS' around where I live, so I'll be buying online. The Competitive Cyclist calculator gives me the following:
So, my problem is this. For this specific bike, if treating the top tube length as the driving measurement, the "large" size is correct. But, this puts me on a smaller frame size, assuming frame size = seat tube length, than most other calculators / tables suggest. If I were to go by frame size alone, I would go for the x-large size in this bike.
I'm sure most people will say go ride a bunch of different frames, see what feels right, etc. But I don't have that luxury due to my location and work schedule. So, should I go for the large size of this bike, which according to CC has the correct top tube length for me, or should go with the x-large size, which matches what I would be traditionally sized with based on frame size / seat tube length.
For what it's worth, I prefer a slightly more relaxed seating style.
My fit measurements are as follows, in inches:
Code:
Inseam 34.25 Trunk 27 Forearm 14 Arm 26.25 Thigh 24.25 Lower leg 21.5 Height 72.2
Code:
Size Seat Tube Effective Stack Reach Head Tube Head Tube Seat
(c-t) Top Tube Angle Angle
XS 47.0 51.5 51.1 37.9 11.0 72.0 74.5
S 50.0 52.5 51.8 38.2 11.5 72.0 74.5
M 53.0 53.8 54.8 38.6 14.5 73.0 74.5
L 55.0 55.7 56.2 38.9 16.0 73.0 73.5
XL 58.0 57.0 58.5 39.3 19.5 73.0 73.0
XXL 61.0 58.5 60.1 40.1 20.0 73.5 73.0
Code:
The Competitive Fit (cm) ------------------------------------------- Seat tube range c-c: 56.8 - 57.3 Seat tube range c-t: 58.5 - 59.0 Top tube length: 55.5 - 55.9 Stem Length: 11.7 - 12.3 BB-Saddle Position: 75.1 - 77.1 Saddle-Handlebar: 55.6 - 56.2 Saddle Setback: 7.0 - 7.4 The Eddy Fit (cm) ------------------------------------------- Seat tube range c-c: 58.0 - 58.5 Seat tube range c-t: 59.7 - 60.2 Top tube length: 55.5 - 55.9 Stem Length: 10.6 - 11.2 BB-Saddle Position: 74.3 - 76.3 Saddle-Handlebar: 56.4 - 57.0 Saddle Setback: 8.2 - 8.6 The French Fit (cm) ------------------------------------------- Seat tube range c-c: 59.7 - 60.2 Seat tube range c-t: 61.4 - 61.9 Top tube length: 56.7 - 57.1 Stem Length: 10.8 - 11.4 BB-Saddle Position: 72.6 - 74.6 Saddle-Handlebar: 58.1 - 58.7 Saddle Setback: 7.7 - 8.1
I'm sure most people will say go ride a bunch of different frames, see what feels right, etc. But I don't have that luxury due to my location and work schedule. So, should I go for the large size of this bike, which according to CC has the correct top tube length for me, or should go with the x-large size, which matches what I would be traditionally sized with based on frame size / seat tube length.
For what it's worth, I prefer a slightly more relaxed seating style.
Last edited by CashewNut; 10-19-11 at 12:06 PM.
10-19-11 | 01:51 PM
#2
Two-Wheeled Aficionado
Joined: Jul 2011
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From: Wichita
Bikes: Santa Cruz Blur TR, Cannondale Quick CX dropbar conversion & others
I can solve your problem. Find a LBS who has some road bikes in stock. Test ride 55-58cm bikes. Find one you like and look up the specs. Compare these specs to your CC bike.
I did this and it's how I ended up on a 61cm Litespeed M1. For me the toss up was between 58 and 60. I didn't like the fit of the 56s at all, even though people my size do ride them (and smaller, even).
I did this and it's how I ended up on a 61cm Litespeed M1. For me the toss up was between 58 and 60. I didn't like the fit of the 56s at all, even though people my size do ride them (and smaller, even).
10-19-11 | 02:04 PM
#3
Senior Member
Joined: Nov 2009
Posts: 58
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From: NYC
Bikes: Cervelo S1
if you are ordering from competitive cyclist, give them a call. they are a very helpful group. adjusting a fit is hard to do on paper alone. if the reach is becoming a driver for size, you have an option of changing stem lenghts etc. a lot depends on how you want to ride which you didnt mention.
10-19-11 | 02:24 PM
#4
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if you are ordering from competitive cyclist, give them a call. they are a very helpful group. adjusting a fit is hard to do on paper alone. if the reach is becoming a driver for size, you have an option of changing stem lenghts etc. a lot depends on how you want to ride which you didnt mention.
I only wanted to pose the question here because all the traditional numbers seem to point to me going with a 58cm or so frame, but CC's calculator shows that I don't have equal torso/arms vs. legs proportions, and hence should go with a shorter top tube, which only exists on a shorter frame size.
10-19-11 | 02:32 PM
#5
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From: NYC
Bikes: Cervelo S1
what brand are you looking at? i had a similar sizing issue (and first road bike) so went with the smaller size, 56. after a few years of riding and adjustments i am going with a 58. did they say what sort of drop to expect with these configurations?
10-19-11 | 02:44 PM
#6
Gluteus Enormus
Joined: Dec 2007
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From: Raleigh, NC
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Big difference in saddle to bar drop between those two but the reach is about the same. I think their stack and reach numbers are wrong. The size L is about right but the XL is off. I figure the stack is ~597 and reach is ~388 for the XL.
10-19-11 | 02:54 PM
#7
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And which has a bigger saddle to bar drop? The L or XL?
Thanks again.
10-19-11 | 03:13 PM
#8
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From: Wichita
Bikes: Santa Cruz Blur TR, Cannondale Quick CX dropbar conversion & others
L. It has a shorter headtube. You will naturally raise the seatpost to the correct saddle height on either bike, but the bars don't come up quite as easily.
That said, you can install a positive stem with spacers on the L and negative stem without spacers on the XL and have the same bar height.
However... I think more likely you will be running spacers and positive stem on the XL, and looking for a 17+ deg stem on the L. I haven't fit you, I just see how these threads go.
That said, you can install a positive stem with spacers on the L and negative stem without spacers on the XL and have the same bar height.
However... I think more likely you will be running spacers and positive stem on the XL, and looking for a 17+ deg stem on the L. I haven't fit you, I just see how these threads go.
10-19-11 | 03:14 PM
#9
Gluteus Enormus
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From: Raleigh, NC
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The top of the head tube is 35mm lower on the size L so that one will allow a bigger drop for you. The stack and reach numbers published for the XL don't jive. I think the actual stack is 597 (vs 585) and the reach is 388 (vs 393). If the geometry numbers given are accurate then either frame can fit you and it comes down to how much drop you want and how much saddle setback you need. You'll end up with a little more setback on the L because the seat tube angle is steeper.
10-19-11 | 03:35 PM
#10
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From: SE Minnesota
Bikes: are better than yours.
The older you are, the less fit you are and the less flexible you are, the more likely it is that you'll be happier with the larger frame.
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10-19-11 | 06:08 PM
#11
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The top of the head tube is 35mm lower on the size L so that one will allow a bigger drop for you. The stack and reach numbers published for the XL don't jive. I think the actual stack is 597 (vs 585) and the reach is 388 (vs 393). If the geometry numbers given are accurate then either frame can fit you and it comes down to how much drop you want and how much saddle setback you need. You'll end up with a little more setback on the L because the seat tube angle is steeper.
As much as I'd like to pretend, I'm not going to be racing this bike. I suspect I'll be more happy overall with a more upright, casual position. Which makes me lean towards the XL over the L.
Over the phone CC did offer to put a short stem on the XL, which I think would give me an even more upright position, but that may be too extreme.
Last edited by CashewNut; 10-19-11 at 06:15 PM.
10-20-11 | 08:44 PM
#12
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From: Loveland, CO
Bikes: Cervelo Rouvida x 2
If you compare the stack and reach values to the old fashioned method of comparing the TT length, with corrections for the STA, both methods suggest that the XL has a 1.8-1.9mm longer reach than the L. What's unlikely is that the stack on XL is only 2.3cm greater that the size L. That would require a significantly lower BB height. Most likely, that stack height difference is 3.3cm.
You can't compare the reach values of frames with different stack heights, directly. To make a proper comparison, the reach of the smaller frame should be corrected to the same height as the larger one. That correction requires subtracting 3mm from the reach for each 10mm of stack height difference. That makes the smaller frame's reach shorter and the difference larger. The assumption is that both frames would be setup with the same total stack, using more spacers on the smaller frame. A frame shouldn't force a rider to adopt an undesired position.
You can't compare the reach values of frames with different stack heights, directly. To make a proper comparison, the reach of the smaller frame should be corrected to the same height as the larger one. That correction requires subtracting 3mm from the reach for each 10mm of stack height difference. That makes the smaller frame's reach shorter and the difference larger. The assumption is that both frames would be setup with the same total stack, using more spacers on the smaller frame. A frame shouldn't force a rider to adopt an undesired position.
10-21-11 | 07:06 AM
#14
Gluteus Enormus
Joined: Dec 2007
Posts: 2,245
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From: Raleigh, NC
Bikes: Yes
If you compare the stack and reach values to the old fashioned method of comparing the TT length, with corrections for the STA, both methods suggest that the XL has a 1.8-1.9mm longer reach than the L. What's unlikely is that the stack on XL is only 2.3cm greater that the size L. That would require a significantly lower BB height. Most likely, that stack height difference is 3.3cm.
You can't compare the reach values of frames with different stack heights, directly. To make a proper comparison, the reach of the smaller frame should be corrected to the same height as the larger one. That correction requires subtracting 3mm from the reach for each 10mm of stack height difference. That makes the smaller frame's reach shorter and the difference larger. The assumption is that both frames would be setup with the same total stack, using more spacers on the smaller frame. A frame shouldn't force a rider to adopt an undesired position.
You can't compare the reach values of frames with different stack heights, directly. To make a proper comparison, the reach of the smaller frame should be corrected to the same height as the larger one. That correction requires subtracting 3mm from the reach for each 10mm of stack height difference. That makes the smaller frame's reach shorter and the difference larger. The assumption is that both frames would be setup with the same total stack, using more spacers on the smaller frame. A frame shouldn't force a rider to adopt an undesired position.
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