green lion

The tread about long legs made me think. Just for personal reference, whom of you would wanna be so kind to mention his inseam length (real inseam, no pants inseam) and current frame size. Also, please mention c-c or c-t for frame size. TT length may also be mentioned. Thanks.

I'm 84cm inseam and have 53 cm (c-c) lemond. 54.5 TT

pokey

35"(89cm), 57cm c-c, 56.5cm TT I can go with a bit bigger frame as long as the TT is not over 57cm and the seattube is 73*,but not shallower.

cycletourist

A more useful measurement is saddle height- measured from the center of the bottom bracket to the top of the saddle. Subtract 15 cm from this to get your APPROXIMATE road bike size.

My saddle height is 78 cm. Minus 15 is 63. Depending on the brand and the bottom bracket height I can ride anything from a 58cm to a 63cm road frame.

Cipher

Inseam 87.5cm, 57cm c-c, 57.5cm TT.

croombr

Inseam 84 cm, TT 54.5, c-c 45.2 (compact), Size S

Barnaby

Green Lion-Trying to get more efficient on my road bike, I started to look at the available advice concerning the relationship between frame and body measurement. Optimal solutions may not be available after having purchased a particular bike. The practical adjustments end up being saddle fore/aft positioning, saddle height, and stem length.
There are various sources dealing with the optimal set-up though before purchase such as the Fit Kit method, and the www.wrenchscience.com site. The later site indicates that I have relatively short legs, especially in the lower leg. The bike I purchased based on inseam was 53 cm. cc. My problem is that my top tube in also 53 cm. The LBS put on the longest stem in stock at the time-a cinelli stem of 110 mm.
I have felt like I was hovering over the bike rather than settled into it like other riders I have seen, and after using the wrench science site, discouvered that my saddle was too high. I lowered it by about 3 cm. and moved the saddle back as far as it would go on the seat rails-another 2 1/2 cm.) The bike feels completely different and takes some getting used to, but it is amazing what small adjustments can do.
The saddle fore/aft is supposed to be related to thigh measurement I know, but by using an improvised plumb-line, I think the centre of my knee is over the peddle spindle.
I am currently on the lookout for a longer stem to further improve overall reach as wrenchscience defines it.
The comment that you received that centre of crank to top-of-saddle measurement is the important one relative to inseam, is I think correct. The book I read says that the tendency is always to have the saddle to high, since that set-up tends to use the muscles that we use as pedestrians. As soon as I lowered the saddle I could feel the difference in the quadriceps immediatly, at the same speed. I must have been using some other muscle group more at the higher saddle height.
It still bothers me that after using the Fit Kit, that the bike store may have sold me a frame that was not ideal for my body dimentions. I think they arrived at some measurements, but then offered the choice of frames based on what was in stock. Caveat Emptor!

Cipher

Very impressive site! I just plugged in my measurements, and checked their dimensions for fit compared to my present road bike set-up and they were either right on or with in ½ cm. :thumbup:

RainmanP

The bb to saddletop minus 15 cm is a concept I have not seen before. It puts me pretty close when I was thinking from other things I have read that my bikes were theoretically too big. For reference, recommended starting bb to saddle height distance is .883 times inseam measured floor to crotch. My inseam is 81.5 cm so calculated bb to saddle top would be 72 cm. I tried this, but it felt way too cramped even after several days. 74 cm feels fine. Saddle type and firmness and fore/aft position can require variations. Using my theoretical bb to st I would ride a 57 according to the -15 estimate. My bikes are all 57 or 58. I think my inseam is short for my height of 183 cm/6'0". On the other hand I have gorilla arms, 35" shirt sleeve, so I am using a very long stem. The setup I am riding on my bikes feels comfortable, but I still would like to get a good fitting sometime.

Cipher

When Setting up my bikes, I have always used saddletop to flat of pedal at the bottom of the stroke. This way if wouldn't matter what length cranks I was using... (This is assuming the use of the same pedals/shoe combination).

RainmanP

I just did the Wrench Science fit program. Came out reasonably close to what I had calculated. The only thing that seems out of whack is that it says I should ride a 53 cm (center to center) frame. With the 72.75 cm overall reach (basically seatpost to handlebar) I would definitely have to get a custom frame to get that reach on a 53 cm frame (short legs/long arms for my height). I already have a 140 cm stem to achieve only about 71 cm reach on my 57 and 58 mm frames though I might be able to squeeze out another cm or so. The 71 is quite comfortable though I was wondering if I was being extreme with the 140 stem. Guess not!

WS calculated 71.96 seat height. I had calculated 72 based on .883 x 81.5 cm inseam. As I mentioned earlier 74 just feels a lot better. I may try 72 again. It just felt like my knees were in my chest and the leverage was weak. Maybe I just need more time to get used to it and recondition the muscles. A young Cat 2 racer friend tells me he immediately felt like he had more power when he moved his seat down a couple of cm to the .883 factor recently.

Just for grins I think I will set my bikes up exactly to these specs and ride it that way for at least two weeks to see what happens.

Barnaby

RainmanP-I am a lot shorter than you it appears, but have long arms for height as well. WS recommends 66.23 cm for total reach, and I have 11 cm in stem and 53 in top tube for 64 cm. I need a stem of 13 cm. to give 66, but right now I cheat by moving the saddle all the way to the rear as I mentioned above. Nose of saddle to mid-bar may be more relevant here for adjusted total reach. I think I can get away with this since I have relatively longer upper legs than lower, so I think I am still over the pedal axel.
WS also advised me to go lower to 67.28 cm. I was at 72 and have since lowered it to 69 cm. The two adjustments have totally changed the riding posture. As I said, I feel it now more in the quads, but I think I am faster, and less bunched-up. I got onto this kick when I noticed that in the TDF Jackie Durand spent all the time in the drop position and his forarms were in front and parallel to the ground, it looks like afew inches infront of his knees. My elbows were ovrerlapping my knees by quite a bit, and still do. With a new stem, I think I can get close to where I should be.
The Wrench Science site system seems correct based on what I feel and observe.