bike fit — confused!

absorption

Hi, I'm looking for my first road bike after riding "hybrids" for a number of years and since I'm spending more money I want to make sure I get a bike that fits as well as poss.

I've been measured at my LBS using bikefitting.com machine and provided with an "ideal" geometry based on height, reach, inseam, shoulder width, etc.

I understand there's no frame out there that is going to match the ideal off the shelf so I'm wondering where is the best place to compromise and what would the effect be if I'm looking for a more relaxed ride (I have some lower back pain currently which I *think* is due to being a bit cramped/short reach)?

For example, looking at bikes out there I see it will usually be that either the top tube or seat tube measurement will be close to ideal but not both. Some are radically out (my ideal CtoC seatpost length is 570 which is near impossible to find and top tube length 590 with is also beyond many XL sizes). I'm 6'1" so I wouldn't think the XLs are too big!

Which dimensions should I compromise, and in which direction (IE should I err on side of having a longer top tube or shorter, or a longer or shorter seat tube?

Any advise on how to eliminate frames from contention and pick a winner?
thank you!

Strith

I'd look to match as best you can to the quoted stack and reach given to you. Most other things can be adjusted around that.
There should be plenty of bikes that will fit you with a little adjustment. Ask your LBS for help.

sancho_uk

The answer generally to this question is...

Get out to your LBS`s and get your backside parked on as many bikes as possible.

If they allow try and many as possible. Even if you found a bike that hit your exact measurements from the bike fitting site you used it doesnt mean it will be comfortable. Its all about trial and error really.

You will find lots of people on the forum probably spent a lot of time bouncing about shops finding out what was right for them.

Unfortunately there is no real definitive answer to what area of the bike you should change as everyone is different.. However the general rule seems to be buy slightly too small than too big as its easier to lengthen the stem etc than it is to shorten other areas..

napoleond

Top tube length is the most important. I'm 6'1" and ride a 58cm top tube with a 120mm or 130mm stem depending on head tube angle.
Seat tube is not particularly relevant as long as the angle is the same, just adjust the seat post.

However! Although the top tube is the most important measurement if the frame (IMO) before dialling in the front end it is imperative you get saddle height and setback correct 1st.

drlodge

NapoleonD wrote:

Top tube length is the most important. I'm 6'1" and ride a 58cm top tube with a 120mm or 130mm stem depending on head tube angle.
Seat tube is not particularly relevant as long as the angle is the same, just adjust the seat post.

However! Although the top tube is the most important measurement if the frame (IMO) before dialling in the front end it is imperative you get saddle height and setback correct 1st.

^--- This. Also check the geometry for stack height as mentioned in an earlier post.