# Fit Advice



## Infini (Apr 21, 2003)

I'm thinking about purchasing a MXL very soon, but I'm a bit confused on fit. I want to make sure I get it right because I'll be getting the Saronni PR82 paint scheme, which I really like, and if I decide a year later I need a different frame size, it could be very challenging to find a PR82 MXL at that point. 

Here are my body measurements: (measured as per the competitive cyclist fit calculator instructions, shown in cm) 

Inseam: 84.8
Trunk: 59.7
Forearm: 34.3
Arm: 60.6
Upper Leg: 61
Lower Leg: 55.2
Sternal Notch: 145.7
Height: 175.3
I'm 26 years old and weigh around 160. I ride recreationally. Most often 50 miles or less per ride, and rarely up to a century. I am fairly flexible - can touch fingers to ground in the old legs straight and bend over stretch. 

I believe that compared to average body proportions, my lower body is long and my upper body short. I currently ride a Cannondale CAAD3 56cm frame. (geometry here: https://de.cannondale.com/bikes/01/geo-20.html ). 

CAAD3 Specs:
Seat Tube C-C : 54 (measured myself) 
Top Tube: 56 (I measure it at 55.2)
Seat Tube Angle: 73.5 
Head Tube Angle: 73









As the bike is set up, I feel comfortable on the hoods. Judging on the angles of the drops and the bars between flats and hoods, I think they'd be better if I rotated the bars up a bit, and in doing that I could probably move the bars forward or down a little. 

The thing that I'm getting confused on is that I'm not familiar with setting up a bike with a threadless headset/stem. The online fit systems I've looked at (competitive cyclist, tiemeyercycle, wrench science) recommend a Top tube and stem length combinations of 61.8 to 64.8cm. I don't know if "reach" is a correct term for that, but I'll use it here. 

If you just add the top tube and stem lengths, it comes out like this: 








Top tube length on top row, stem length in left column, totals in chart. All green combinations fit in that 61.8-64.8 range. 


QUESTIONS:

1.) To get that reach number, do you just add the top tube and stem lengths? Or do you have to take the head tube and stem angles into consideration? I've done some geometry with the position of my bars compared to the headtube and fwiw, if anything,.. my rough GUESS is that to have the bars in the same spot relative to the top of the head tube if using a threadless stem, I'd need 2.8cm of spacers with a 10cm 9 degree stem. 

2.) Am I going about this wrong? Am I making it too complicated? 

3.) And what I'm really trying to figure out,.. what frame size do I need?



Here is the MXL Geometry:


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## rdolson (Sep 2, 2003)

That is a VERY steep rise you have on your C'dale stem. You end up with a very short effective stem length and not much saddle to bar drop. 

Normally, you want the tops or the bars level, not sloping down like you have. I think that is a result of the steep stem angle.

I would say that you are going about it the right way. 

Probably the 57cm MXL would be a good fit, based on looking at your current set-up that you say is comfy.

Start with a used stem from your LBS, that way you can play with length and angle for a good fit. Most shops will let you swap 'em around til you find a good fit, then pop for a new one if you want.

Also, you want to leave your steerer long with lots of spacers at first. Shuffle the spacers moving the stem up and down til you find the sweet spot. Then you can trim the steerer to size.

All the fit calculaters can do is get you in the ball park. From there, it's up to you to fine tune to what works for you.

I have an MXL and can assure you that you would be very pleased once you get it dialed in.


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## Infini (Apr 21, 2003)

Thanks for the reply rdolson. 

I just checked and I have the stem down as low as it will go. I think the big stem may be the reason I had the bars tilted downwards like that, in order to get the hoods where I wanted them.. I know, it's the wrong way of going about it. I'm pretty sure that I would be comfortable with the bars lower and/or forward. (mainly lower; just a tiny bit forwards)

I had been thinking a 56, and maybe even a 55 in order to get a top tube length I think is good. But, of course, I don't know! 

I wish there was a Colnago dealer near so I could go take a look, but I live in Nebraska and there isn't much of anything that's italian here.


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## tmluk (Sep 19, 2005)

If you are comfortable with the fit of your current bike ... my comments

(1) It not unusual to have the bottom flat of handlebar tilted 5-10 degree upward. This would raise your hood some what. But measure the following with current set-up.
(2) It would be useful to have the following info of the bike set-up ...
2a) saddle height (red line)
2b) saddle to bar-top drop (green line)
2c) post to bar-rear reach (blue line)
Accurate to 0.5cm should be suffice since you're just trying to figure out the frame size.

From here we can figure out a reasonable seatpost, stem extension/angle, and stack height for a frame size.


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## Infini (Apr 21, 2003)

tmluk said:


> If you are comfortable with the fit of your current bike ... my comments
> 
> (1) It not unusual to have the bottom flat of handlebar tilted 5-10 degree upward. This would raise your hood some what. But measure the following with current set-up.
> (2) It would be useful to have the following info of the bike set-up ...
> ...


Here are the measurements: 

2a.) Saddle Height: 76.8cm
2b.) Saddle to bar (top) Drop: 6.0
2c.) Post to bar (rear) reach: 63.8

The reach falls in the range that the fit calculators give me. I could probably go out another cm on reach with no problem, and MAYBE 2. I think I could also go down 2-3 cm on the drop (up to 9cm) and be fine. I am certainly comfortable with how it is set up now, but that is not to say that I can't go any further,


I have a couple other bikes and measured those also: 

FIXED GEAR: 
2a) Saddle height - 77.5
2b) Drop - 8.3 
2c) Reach - 62.2

TOURING BIKE: 
2a) Saddle height - 78.1
2b) Drop - 3.8
2c) Reach - 65.4

The drop on the Fixed gear is more, and it feels fine. The reach on the touring bike feels like it's as far as I can handle, and I would prefer it to be a little less. 

(I was surprised how much the saddle height varies by bike)


So, I would say that these numbers sound nice to me: 
Reach: 63.5 to 65
Drop: 6 to 9


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## Infini (Apr 21, 2003)

I did some more calculations. I used this http://www.zinncycles.com/stemFit.aspx to calculate horizontal (X) and vertical (Y) position of the bars relative to stem mounting position for different stem lengths and angles. 

I made formulas to calculate drop and reach based on X, Y, the top tube length, the amount of spacers, and the head tube and seat tube angles. From that it looks like a size 56 frame with a 100mm 9 degree stem (mounted rising) along with nearly 3cm of spacers would give me a reach of just under 65cm and a drop of just under 9cm, which would work for me. 

Along the same lines, I think the following combinations would also be fairly close: 
55 frame. 110mm stem. 4cm spacers
56 frame. 100mm stem. 3cm spacers
57 frame. 90mm stem. 2cm spacers

(I'm at work now so I can't calculate the numbers, I'll do so when I get home). How much does the stem length affect handling or ride quality? 

Now,... assume that my geometry is all wrong, because it might be.... - Based on my body measurements and desired dimensions for drop and reach, does a 56 frame sound right?


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## tmluk (Sep 19, 2005)

I am of similar conclusion with the stem length. It is a toss between 56cm with 100mm stem vs. 57cm with 90mm stem. My opinion is goping with 56cm.

(1) The seat-tube angle is same as the current bike (73.5-deg). Thus, setting up your saddle set-back is the same.
(2) The seat-tube length is about the same also. Looking at the picture, there is reasonable amount of exposed seat-post to adjust.
(3) There is more room to play with a 100mm stem than a 90mm stem. Most stems starts with 80-90mm ... I think.

It is odd how all your bikes have such different saddle height.


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## Infini (Apr 21, 2003)

I went ahead and ordered a 56 today. I spoke with Ben at CBIKE and he recommended a 56. 

They are expecting to receive the frame in late March or April, so I'll start getting components ready. I'll be pulling the 9 Speed record off the Cannondale, and I think I'll go for the shiny metal look on the seatpost, headset, stem, and bars. I think a saddle change will be in oder also. 

Thanks for your help, guys.



Note - yeah, as I said I was definitely surprised by the saddle height variances. I think some of the difference is because of the different saddle, shoe, and pedal combinations I use on the different bikes.


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## Infini (Apr 21, 2003)

*Got the frame today.*

and it looks beautiful. 

Here's what I'm building it with:

Here's what I'm going with:

-Fork- Steel (chromed) Colnago Precisa. 
-Grouppo- Centaur with Chorus shifters. (to save some money)
-Cranks- Alloy
-Wheels- Getting a set of wheels made by Mike Garcia. For now CPX-33s off my other bike
-Headset- Chris King Silver. I tried getting a Chorus headset from Lickbike but they are all out
-Stem- probably will go with a Silver Thompson X2
-Bars- Deda Newton. Got the dark metal polish. Cleaned that off with Lye and polished it up. Now it's bright and shiney as hell, just the way I want it!
-Seatpost- Thompson Elite Silver.
-Saddle- Sella Regal saddle, white
-Bar Tape- White. And I will try white HUDZ (brake hoods). I don't think they feel as nice as campy, but I do wear gloves all the time so I'll give them a try since they look so good.

I'll post pics once it's built.


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