Help With Frame Size
 

I am looking at a 58cm Cannondale CAAD5 frame with a 57.5 cm top tube length. I am 5'11'' with a 31.5in inseam, do you think that this bike is too large? Thanks. It is a great price and I really want to buy it!

Sounds a bit large to me, I would check out wrenchscience.com input youre measurements and see what it recomends. I believe with a 58cm seattube the stand over height would be almost 32 inches.

Very easy to find out - Just ride it around the parking lot. You will find very quick if it is too large for you.

I am not a fan of formulas like many sites post because they are generic and very bad to use to determine frame size. Everyone is different with different needs and likes, a formula on some site can never tell you what you should ride.

Just throw your leg over it and you will find out. If it feels to short or too long (top tube).

A few cents:

(1) A ride around the parking lot is far from ideal: too short to find out what the bike does to you and will most likely be biased towards acrobatics, rather than 'real-world' riding. If possible, ask for a longer test ride.

(2) Formulas can be helpful in establishing some 'outer limits'; they will tell you which frames will be too small and which ones will be too large. The rest requires good on-the-spot advice, trial and error, fine tuning and component selection.

(3) Don't bother too much about standover height. In the long run, the lenght of the top tube (and of the stem) affects your position on the bike.

(4) A new road bike will not feel particularly nice, even if it fits you 'perfectly'. They take some time to get used to, even the models that are known for 'comfort'.

I just got a CAAD5 C-dale frame, it's a 60cm and I am 6'2" and I had it fitted. I would think that the 58cm would be too large for you. Have a fitting done at a good shop and see. The good shop will not sell you a frame that is the worng size. There is no shortage of smaller CAAD5 frames so don't worry about losing this one.

Well, if that is your "biking" inseam i/e pubic bone to floor, that bike is definitely too large. If it is what size pants you wear, measure it like they tell you to on wrenchscience.com

I have a 34" inseam, and that cannondale is the right size for me. (if you pass on it let me in, hehe) But I wear a 32" pant leg...

Think about it, it has a 32.5 inch standover, you have your crotch separated from the ground by 31.5 inch. There will be contact and it will hurt.

You can make a too small frame fit, but too big beyond a certain point and there isn't anything that can be done.

I have a 61 cm frame I bought new in 86. Standover is 34 in, same as my inseam. I can ride it if i wear shoes, but it just doesn't fit standover wise and every other way. I wish i hadn't bought it.

So, the moral is, too big is almost unridable.

take care,

Jester

GOLDBURG, I just have to kick in here. I have almost the same stats as you do. On wrenchscience and fit kit it suggested 53cm frame. Being long in the torso and short in the legs I opted for a 56cm at the suggestion of the LBS. I have been generaly happy with the choice. I wouldn't want a MTB that was "too big" because you never know when or in what condition you will have to step off onto. On a road bike I just have learned to sorta lean the bike to the dismount side and this lowers the standover hight. I have never had a problem with either of my bikes and beleave me they are a tight fit if I stand upright over them. The top tube length is more important, in my opinion, than the actual frame being a little large.
Case in point, my coworker rides a 52cm frame. I have ridden it and the saddle hight is in just the right place for me! On the other hand I'm cramped up on the top side on his bike. I have a HUGE ol Trek 850 mtb in XL size the I use for commuting etc. but I wouldn't think of using it for a real off road bike. I am very cramped in the nads if I try and stand flat footed over the top tube, this bike doesn't have a sloping TT, but for the kind of ridding I use this bike for it works great!
If you can test ride a few in different sizes I would do so before taking a hit in the wallet!

PS On the 56cm road bike I have a 120mm stem to make the cockpit a little longer still.

I agree the formulas' are not exact and could be way off but it gives you a good starting point.

Thank you for all your replies. I actually remeasured my inseam today more exactly and found that I am hovering between 32 and 32.5 inches. The previous rider of the bike was the same height and a 33 inch inseam. My local bike shop told me that the tube top was more important than the frame height. I think I am going to purchase it! It is a good deal and I will make adjustments if needed to make the bike fit! Thanks again!

Well,

Yes, top tube is more important than seat tube IF you can stand over it.

You will likely be okay as long as your shoes have a fair ammount of sole to them, but as the frame measures to 32.5 standover exactly same as your inseam, I wouldn't do it. However, its your money and i've been told i'm a picky bastard, so good luck.

I guess my opinion is if you can't use it, any ammount of money isn't a good deal. well, unless you can resell it for more on e-bay ;)

take care,

Jester

i dont mean to hijack this thread but i am short... i'm 5'6" and have an inseam of 72cm... what should be my size..

I know its a personal thing, but what size should i get? I am currently riding a 51cm frame... Do you think its too big for me?

I can't really try a smaller one, since I think its the smallest frame around... But I can build one... I just have to be sure what size...

So, what do you think?

Thanks..

uciflylow above just pointed out how bad it is to use formulas. Thank God he didn't rely on that website as many do.

Far too many people see fancy sites with formulas and end up really wasting a chunk of money and time. Nothing beats a real person, even on the phone. Always talk to a real person that knows. Not just some computer or a guy on the phone inputing your numbers on the computer.

You know that "fit kit" that the bike shop used was almost identical to the wrench science results. The important thing is that the bike shop owner just kept looking at me and said " I have been selling bikes for 25 years and I realy think you will be better on a 56cm". He even offered to order a 54 and 56 let me ride them and choose the one I wanted. This is one advantage to using a bike shop. If I had gone by just what the www said and ordered a bike I would have probably been displeased.

I would like to ask and try out a smaller frame... But I don't think it comes any smaller than 50-51cm..

Anyone have a 72cm(28.3") inseam out there? what frame size do you use?

Is a 60 cm frame ok if i'm 6 ft 1 tall ?

There are small frames out there, Bianchi has 49cm as do
other builders. If your particular dimensions are really out
of the norm you might have to go with a custom frame.
check out a few LBS I'm sure you can find something
smaller than a 51.

Marty

A 60cm Cdale has a 59cm top tube... what are you riding now?

I'm 6'1" with a 35.25 inseam and find the 60cm Cdales to be too tall. I can't get my bars low enough with the tall headtube.

Thanks... I made myself a 47cm bike yesterday.. I think this can give me enough room( i think i will have a 2-4cm clearance when im standing) I have a slightly longer toptube, 53cm.. I have long arms, what can i say...


Its a lot of work though, I have to adjust the seat stays too.. I'll be painting it this week. I'll post pics..

Is there any table for Cannondale bikes sizes and people's hight? or recommended hights for C'dale frame sizes?

Dex,

you MADE it? as in brazing, or tig welding etc? or do you
mean you found a 47cm frame and are building it up?
(just curious).
If you need 47st x 53tt then you are really getting into
custom territory (or are gonna have really long stem and
that pull your whole geometry off). Check out Serotta's
web site click me
for info about custom sizing. Lots of other custom
builders out there also.

Marty

Two measurements used,cc and ct,both center of bb to ct-top of tt and cc-center of tt.Lemond uses cc.I ride a 58 but a 57 in a lemond.ct measures about 1-1.5 cm more then cc.

Marty,
Yes, I have customized bikes and experimented on geometry in the past. I have only been into road frames for the past year..

I got into customizing/building frames when I was still in college.. I used this "obsession" to make my thesis: which is also a bike related(a 2 seater recumbent w/ 4wheels and a single seater recumbent with 3 wheels)...

I design the frame.. I take care of all the specifactions. I can get tubes from older frames(mostly cromo)and just have my welder weld it for me. Parts that need to be machined are done by another person.. I would do it if I had the time(I did it in the past when I had the time).. Custom Painting is also done by another person..

Total Cost per frame? I lost track........

I am still not sure if this geometry will work.. But I'm Optimistic. I don't sell my frames(just in case if you ask).

I have read a lot of articles on fit, and what strikes me is that the best fit might actually vary for a given person as the person becomes more or less fit, and more or less accustomed to a particular geometry.

I have ridden a bike I could not straddle for many years. It was and is comfortable, in part because it has a long top tube, (I am 6'2" with a 32.5" bicycle inseam, and relatively short arms) and in part because the handlebars are relatively high in comparison with the saddle. An added bonus is that the torque on the saddle is somewhat lower.

What I don't know is if a different geometry would work better for me. I think if I were to do a fit kit or something like that, and follow recommendations, then, after I acclimated to the bike I might like different geometry. I could not discover this with mere test rides, as any new geometry will feel awkward for the first dozen or so hours. Further, if a geometry were to be ideal now, and I were to get fitter, then it would no longer be ideal. I think formulaic approaches may have a lot going for them, and if they don't work well, then the formula needs adjustment. Further, there is no substitute for experienced judgement in helping interpret what the results of such a fit kit type approach means. For example, my proportions are a little diferent. It would be good if an experienced hand were to tell me what worked well for a long torsoed individual at a similar level of flexibility and fitness, and how those meassurements compare to fit kit recommendations. I don't think there are a lot of those kinds of folks around. Even if there were an abundance of such folks, just read several threads on fitting. One guy will say all bikes today are too small, another that most are too large. One will criticize KOPS, another may use it. They are experienced in fitting many riders, and I am not. There appears no way to pick your way through the maze of opinions. My best take- find a bike that feels ok in a test ride, and meets most recommendations, and try it for a while. If you feel like you need to change something, start by moving the saddle fore/aft, then try longer/ shorter stems. When you have a better idea, then shop again.

DexMax, I'm impressed. would like to see pics of your
frames/bikes.
FOG yes definately! fitting requirements change as fitness
levels change. My own geometry requirements are not
the same as they were when I was 20, more flexible and
had less weight hanging towards the toptube (hey I'm not
that bad, but yes I've gained a few since then).
I prefer a more upright position than before (no, not hybrid
upright, just higher stem relative to saddle), less drop
to the bars.
If you go to a good fitter (serotta is great for this), about
1/2 of the time spent is more about your riding style and
less about hard measurements.
Of course a good fitter will know how much change is going
to occur in your personal style/fitness based on the info you
provide to make choices in Geometry which will be correct in
say 6months, 1 year etc.
And therein lies the key, be honest with the fitter, and
yourself.
Check out the Serotta web site (see Serotta thread) for
more info about their fit system.

Marty