|Are my measurements normal?||Gerbila|
Sep 13, 2003 8:31 PM
|I'm 5'8.75" w/ a 32.75" inseam. Does this seem like normal proportions? The reason I ask is because I just built up a 54cm (55cm effective TT) Fondriest MdC w/ a 110mm Deda stem (120mm reach). I figured since I am a standard sized Medium person that these would be standard Medium sized things I should fit. Well I feel too stretched out on the hoods, and the bars do not block the front hub. The position most comfortable is 3-4cm back from the hoods, which actually does result in obstruction of the hub. My question is, it seems I would need a stem 3-4 cm shorter than my current one, such as a 90mm, to get to this comfortable position. But a 90mm seems awfully short for a medium frame, and since I've always thought myself normally proportioned I am hesitant to go through w/ this. My saddle fore/aft is adjusted correctly, so it's not that. What do you guys think?|
|I think that you need to get somebody local to fit you.||Spoke Wrench|
Sep 14, 2003 5:47 AM
|You didn't say how you measured your inseam length. You also didn't mention handlebar height at all and I think that's a real important consideration. It seems to me like you are taking kind of an analog "medium" approach to everything else and expecting to get an exact digital answer.|
|The frame should be about right ....||bent_spoke|
Sep 14, 2003 7:45 AM
|since the Fondriest has a sloping top tube. I've got a 31" inseam & a 54cm frame (a little big). I've used a stem with a little rise to compensate for the reach & to add comfort.
You might want to check out the wrenchscience.com site to get some fit recommendations.
|not considering the saddle placement....||C-40|
Sep 14, 2003 9:35 AM
|I have a nearly identical inseam, but at 5'-6.5" chose the 51cm MDC, with a 53cm TT. I use a 110mm stem.
I don't know why you think your 110mm Deda stem has a 120mm reach. Can you explain that?
The position of the saddle changes the total reach. Most saddles have at least 3cm of adjustment. A "correctly" adjusted saddle could be anywhere in this range, depending on your preferred KOP position and demur length. If you have the saddle most of the way back you could easily need a 90mm stem.
Don't go by the bars obscuring the view of the hub guidleine, it's pretty worthless. Of more importance is the angle between the arms and the upper body and knee to elbow clearance. If you have any clearance between the knees and elbows when pedaling in the drop section of the bars with your finger in reach of the brake levers and the back horizontal, then the stem is long enough. If you have lots of clearance and feel too stretched out, then the stem is obviously too long.
Bar height is also important. You don't mention your stem angle or the amoutn of steering tube spacers that you are using. Assuming that you have the Deda 80 degree stem, you can "shorten" the stem to approximately a 100mm reach by flipping it over to produce a 100 degree angle. To maintain the same bar height, 2.5cm of spacer would have to be removed from under the stem and placed on top of the stem. If this setup is not short enough, then you can move on to a 90mm stem.
|not considering the saddle placement....||Gerbila|
Sep 14, 2003 10:27 AM
|C-40, I was hoping you'd respond to my post. I always read your posts about fit w/ great interest (not that I don't appreciate all the other input I've received as well!) The reason I say the stem reach is 120mm is because I measured the effective reach for the frame which is 55cm, and the overall reach was 67cm, so I figured the stem was 120mm. Also Deda told me the 110mm stem size is a measure of stem extension, so from the faceplate along the stem to the middle of the steerer clamp part. Since I have my stem set at 80 deg (or -10 depending on how you look at it), the horizontal reach of the stem is the hypotenuse of the triangle formed w/ the stem and headtube, and is slightly longer than the actual stem length. So mathematically it seems to make sense.
I've measured my KOP and I believe it is currently neutral.
In terms of my knee-elbow clearance in the drops, how is this measured, with the cranks at 3 and 9, or just at the point where the knees come closest to the elbows, which is more like 11 and 5. At 11 and 5 I have about an inch or two of clearance.
My saddle to bar height is 9cm, w/ 2 cm of spacers. I have an extra 1 cm of spacer on the top of the stem I can put underneath.
My final question concerns the concept of effective reach. According to lemond, I should have 70cm or reach, which is what I have on my mountain bike and which feels comfortable. What I dont understand is why effective reach on a roadbike doesn't seem to take into account the extension provided by the handlebars. On a flatbars bike, effective reach is basically the reach you're gonna get. But on a roadbike it seems that extra length provided by the handlebars should really make a difference and is not being taken into account. That's my big problem, I am not comfortable with my hands all the way out on the brake hoods. I am more comfortable with them in the drops. And like you said clearance in the drops b/n elbows and knees is important. But how important is comfort on the hoods, since supposedly 90 percent of the time is spent there (though in my case I spend most of my time in the drops). As an aside, why don't people spend most of their time in the drops since the purpose of a roadbike is to get aero?
Thanks very much for your help!
Sep 14, 2003 12:15 PM
|A stem is never longer than it's advertised length. The horizontal reach of a 110mm 80 degree stem is 109mm.
What I find interesting is the bar to saddle height difference. Seems a bit large for having 2cm of spacer under the stem. Measure and post your saddle height from the center of the BB to the top of the saddle. Mine is about 71cm for example.
I would flip the stem and remove the 2cm of spacer and try that as a starter. It will reduce the reach by about 1cm without changing the bar height by much.
Sounds like you have plenty of (extra) stem length. As long as you don't hit your knees an elbows together, the stem is long enough.
I never pay any attention to fit formulas that try to predict total reach. None take into account the saddle position so they are pretty much worthless.
Sep 14, 2003 12:46 PM
|My saddle height is 75 cm. Seems strange that our inseams would be so similar and yet the height would be different. This height is comfortable for me and has not caused me any knee problems or rocking of hips.
I might consider flipping the stem over, though I confess to being a bit superficial and not liking the look of the stem that way. I had thought about putting that extra 1cm spacer underneath but am worried that 3 cm on a carbon steerer is too much.
Thanks for your input.
Sep 14, 2003 6:31 PM
|75cm sounds high for your inseam, if it was properly measured to firm crotch contact in bare feet. I use speedplay pedals which produce the lowest possible saddle height.
Check that you can drop your heel several cm below horizontal with your leg locked out at the bottom of the stroke. If not, your saddle may be too high. A saddle that's too high won't prduce discomfort but can inhibit your cadence and power output, along with creating a need for too many steering tube spacers. Look at the pros riding the Vuelta right now. It's rare to see a leg without a significant bend at the bottom of the stroke.
The suggestion to flip the stem was considered a cheap and easy way to try a shorter reach. Although you may not like the look, it's certainly no worse than 3cm of spacers under the stem. Either one says you have a fit problem. The higher rise stem will produce a more rigid setup without the spacers.
Sep 15, 2003 8:00 AM
|The "rule of thumb" FWIW is 83cm x .883 = a hair over 73cm.
How much of a difference can Speedplay pedals (compared to SPD or Look) make in terms of a lower saddle height?
|yes, about 1cm, .883 is meaningless...||C-40|
Sep 15, 2003 7:00 PM
|Speedplays with sidi shoes can drop the saddle up to a 1cm. perhaps a bit more compared to some other shoe and pedal combos.
The .883 times inseam has been around since the days of toes clips. Pretty worthless, IMO. Much better to insure that the there is a significant bend in the knee with the foot horizontal at the bottom of the stroke. Better advice than any formula.