sydeshowbob

Ok.. another frame size question. First, of all i dont want to start a debate on how to size a frame. Just wanting some info. I stand 5'4 with and inseam of 29.5 ". My current frame is a compact 50cm. I rode a 52cm frame (motobecane grand sprint), since the frame is a bit more traditional i did not knwo what to expect. The stand over height left me 3/4 to an inch of room. it seemed to ride fine. i was reaching a bit but had made no adjustments to the fore/aft position yet. I am wondering since most LBS say my frame size is a 50cm, is it possible that i could ride a 52cm frame.. if so how do in know that the frame is really to large.. other than my "boyz" touching metal at the top tube. thanks

Patriot

What you need to remember more than anything, is the most important measurement really is your top tube length. The frame size is usually labelled by using the seatube length, which means that your reach (top tube) could be anything. The only thing to do is measure the top tube and find out what length top tube and what length stem is generally best for you.

If your saddle is etup with a good knee over spindle, and feels good, don't mess with that as much, since that affects your knees and your ability to produce power.

If the top tube length between the two frames is almost exactly the same, which is quite possible, then they should feel very similar. If anything, the slightly larger frame may feel a little nicer (smoother), since it has more traditional geometry instead of compact, and thus the triangles are slightly larger to offer more vibration absorption. Compact frames with smaller triangles will naturally feel a little stiffer. (usually).

Anyway, if the reach feels good, and you still have proper arm extension, and good angular posture (upper body) in the various hand positions, then I would really make sure you give it a good long test ride first before you make your purchase.

I know you are male, but as an example, my wife is 5'3", and rides a 49-50cm frame. Mainly because being female, she likes a slightly shorter top tube (less reach). For a male of your height, I can only guess, since I don't know your exact measurements, but a 52 should fit ok, with a proper stem length. This is of course only guessing, since we are on the forum. So, take it all with a grain of salt.

Happy riding.

sydeshowbob

Thanks for the input.

MichaelW

If your std frame size is 50cm then in a compact, you should be riding something smaller, which gives you a few inches of clearance. The smaller frame should be shorter and the reach will be more comfortable.
Work out how long you like your reach to be, then see if the frame can accomodate this without using extremes of stem length. For small frames a stem of 6-10cm is usually OK.

sydeshowbob

My frame now has a top tube of 52.5 cm. Now, a 50cm in the bike i rode (traditional frame) had a top tube of 51cm and the 52cm bike i rode (traditional frame) has a top tube lenght of 53cm. so there is a .5 cm diff either way. I am guessing with additional adjustments to the saddle and bar position, that the 52 may just work. or is .5 cm on the bigger side just to much to give ?

sydeshowbob

Just to clarify... i was sized a 50cm in a compact frame (particularly specialized Allez). So perhaps i would need a slightly larger frame with a traditional geometry frame?

Patriot

Someitmes it works like that. For example....

I am 6'2". My Centurion, is a traditional 60cm frame with a 59cm top tube. My compact, is a 58cm frame with a 58.5cm top tube. After setup, the reach is almost exactly the same, and I love to ride both.

So, to answer your question, I don't think a 5mm differance is enough for the average person to really notice.

If you want, you could always go to a stem to give yo the same reach. Or, if your knee over spindle is good, you can slightly adjust the saddle.

I would give it another good ride first, and have them make a couple minor adjustmenst just to make sure. Never buy a bike unless you really feel like it is part of your body. Almost like it was meant to be there. Otherwise, you may regret it down the road. Bikes are very personal, and it just has to fit like a glove, in order to be truly happy with it.

KirkeIsWaiting

Ok.
If that's true how do you buy a frame to build a bike?
Or a custom frame for that matter.
My dilemma.
It might seem like a dumb question to ask but I'm riding new road bikes and none feel right so far.
I'm learning what I don't like, at least.
But can we assume that if the geometry is perfect for you, the bike will be as well?
Or has my old bike conformed to me, in way?

Patriot

Well, that is a whole topic n itself. In my case, I had only been told what the differance in a cf frame was, compared to aluminum and steel. So, I went to the LBS and test rode a couple differant bikes with cf frames. My purchase of my frame was basically just based on the feel of other similar frames, armed with the knowledge of kowing exactly the geometry and measurements I was looking for. The only unknown factor in my case, was the feel of the ride when built, since cf frames tend to differ a bit between differant brands and designs.
After my build was complete, my expected performance, and feel of the ride was exactly as I had anticipated. So, I was lucky in that respect. The key, is to do lots of research, and not be afraid to ask lots of questions from differant people to get a whole wealth of opinions and knowledge. Then, you just form your own personal opinion, based on what you personally want, and go for it.

sydeshowbob

Ok here is the verdict.. I rode a few bikes the other day, of which include two treks... the 2100 and a 1200 (52cm). Funny thing is the cheaper 1200 (tiagra) components felt exactly the same to me. Only difference was the 1600 dollar price tag on the 2100. In the end the motobecane grand sprint (52cm) was what i went with ... for the money and the componenets i got, it was the best deal.. and the road test was very good compared to the other "big" names. i will post how well it holds up .. my wife and kids all have motobecanes and they beat the hell out of them (mtb).. so we will see how their road frames hold up... they look the same as the kinises frames. anyways... thanks for the input.

KirkeIsWaiting

like any other purchase, I know I'll be most satisfied when I've done my research. And I'm beginning to understand the geometry.
Could you get a good feel of your wife's bike even with the difference in size?