How difficult would it be to make a 58cm frame work for a 6ft. guy who has longer legs? I usually ride a 60 cm but was wondering if anyone had experience in riding a smaller frame.

At 6',
I might consider a 56 or under smaller.
A 60 would leave me stretched out.

Of course this is a generalization, but what size stem do you have and how far back is your saddle on your current bike? If you have a cm or two to play around with on each end, you should be fine. If you're on a 120+ stem and your saddle is back as far as it can go, you're running out of room with a 58. Also keep in mind your bars might be lower as a result.

Example: I have trouble running smaller frames because my long thighs like a laid back seat tube.

60 seems big...

i'm 5'10"-ish and ride a 54...57 is getting big

6' 1" and was riding a 56 cervelo. most recently got a 08 Orca and switched to 57 only because Orbea gaps out from 54 to 57cm. I had a 58 specialized and It felt too big. I'm all legs , like a frog. the 57 fits me to perfection. a little more relaxed. the Cervelo was set up very aggressive with steep angle on the stem and had some serious drop from saddle to bars.

I'm 6' with a 33.75" cycling inseam. I prefer a 60 and have 3 of them.

I also have seven 58's, all of which fit quite well. It wasn't too hard to get all 10 to fit virtually the same.

55/Rad

I'm 6'1+ and am on a 58 (just went down from a 60) and feel very comfortable, though with the stem that the shop had the bike set up with left me feeling more stretched out than on my 60...go figure. They put on a shorter stem and the bike fits perfectly. Easy answer: ride the bike.

I'm 6'1.5" and am on a 58cm bike. My Madone's seat mast barely goes high enough for my legs though. I was also pro-fitted to the bike, and I'm confident with the guy who fitted me. Just as a heads up though, even though a bike may feel comfortable, it still may be the wrong size. I managed to ride across the country on a 62cm bike with a 130mm stem. I was setup for a guy who was 6'4", but it felt fine to me.

a 58cm is not always a 58cm. I ride a '59cm' and the TT is 58.3cm c-to-c.
You will lose big power if your saddle is set too far back or your center of gravity is not correct due to longer stem, etc.
Oh, sure. you could make it work, but the #1 key to riding is comfort & function.

A good deal on an ill fitting bike is not a good deal.

6'1" 34" cycling inseam. I've got a 60cm Paramount, a 59cm Merlin, a M/L Giant which is nominally a 57cm.

They all fit. The point being the nominal measurement of the frame isn't the end of the story, and what you fit on between 2 sizes may vary from frame to frame, depending on geometry, and how that manufacturer measures its frames.

For a long legged rider in particular, all depends on what kind of saddle to bar drop you prefer. I am the same...6'1" with a 35" cycling inseam. I ride a Look 57 c-t-c which = 59 c-t-t. I use a riser stem and some spacers to minimize my saddle to bar drop because I don't like a lot of drop. So ask yourself what kind of drop you like. If you like your bars up higher, then choose a frame with a longer head tube...say a 60 c-t-t. I have ridden a 61 c-t-t Bianchi with 200mm head tube and was pretty comfortable with a 100mm stem. Long legged guys have to pay particular attention to frame sizing. Most that don't want a lot of drop end up on one size bigger bike with a shorter stem.
HTH.

We are about the same size except I have a 35" cycling inseam. I would be on a Large Giant for a bit longer head tube.

I'm 6ft with long legs, and I like 58s. My 4 favourite bikes are three 58s and one 57.5

I've got a 56cm Scapin that I feel is bit small for me, as was my 55.8cm Cinelli and my 56.5cm BMC.
The BMC Streetfire was ok; maybe coz it had a large-ish head-tube for a 56.5.

You've gotta check the head-tubes lengths (coz bikes of the same size can vary a bit in length) then figure out if your bars will be high enough for you without stacking too many spacers. My 58cm aluminium Soloist has a much smaller head-tube than my other 58s

Two many variables. I've ridden several:

61 Bianchi
60 Trek
58 Cannondale

The Bianchi likely fits the best, but has a 105 stem, vs a 120 on the Trek, and a 130/140 stem on the Cannondale.

My Trek is the best bike, and that is what I ride the most.

Depends upon the frame, how it's measured, how flexible you are and whether your arms are long too. There's no way to tell without the rest of the information.

with a long stem and set back seat post any bike can fit- pros routinely ride smaller frames for weight savings- but only so far

My Trek says it's a 60 but measures out to a 58. I am 6'2". Next bike I will just get measured and see how it works out. Best thing to do is get fit to the bike whatever the frame size might turn out to be.

Try measuring it from the center of the BB to the top of the TT...

What you're hearing is that none of us can say for sure without seeing you on the bike, due to diffs in bike sizing, bike customizing, and your own personal flexibility and preferences. In true BF form, however, I'll throw in my two cents:

I bet you're going to have a tough time finding a bike to fit you. The bike sizing fashion of many manufacturers today favors riders with short legs and long torsos. That means you end up with the seat too high relative to the handlebars. Trying to fix that with a larger size bike means you end up with the handlebars too far from the seat. Trying to fix that with a short stem sometimes works, but if it doesn't, then you're back on the smaller bike and trying stem extensions, which are ugly to say the least.

You're best bets might be to look at bikes designed with more upright geometry (handlebars basically level with the seat). You'll end up raising the seat more than they expect, which will get the handlebars back down where many of us like them, but not too far down - and the reach won't be bad since you're going with a smaller size to begin with. I don't know your price range, but the Bianchi C2C series or Specialized Roubaix series are good places to start if they fit your budget.

Indeed. I am 6' with a just about a 34" inseam and I am currently riding an older Lemond that was supposedly a 60cm, but measures 58.5 c-c, with the top tube measuring the same. It fits fine (although my stem is a little long) and is quite comfortable. it's probably a touch too large for me so I am now looking for 58cm. It probably won't be the most aggressive of stances (usually attained by a smaller frame), but I don't need to strive for that look, not to mention that my flexibility is merely adequate.

The problem is that every frames seems to be measured differently or the geometry is so different that conventional measurements don't apply correctly.

A 58cm frame with fairly conventional geometry should fit you fine. The 60 might require less bending and be easier on your back and neck. In part the choice depends on what kind of riding you do. Do you just want to go fast, or do you want to go long distances? Speed = smaller frame; Endurance/distance = larger frame (huge generalization, I know).

No one is talking about top tube length here. I too ride a 59 cm Merlin, am 6'2" and use a 120 stem. The top tube is 58.75 so it's a long relaxed Euro style frame. I also have an older Cannondale 58 with a 57 something top tube and 130 stem. Although the Cannondale is very responsive, it some times feels darty.

my rides are a 59cm Wojcik with a 57.3 tt and my Concorde is a 58cm with a 57cm tt. i got long legs and a short upper body. i think my stems are both 120.

6'2'' 35 inseam and my 57'' Litespeed provides a perfect fit. Depends on the particular frame and rider. For me the less bike the better. When in doubt I'll go a size smaller.

6'2", 36" inside leg, long arms. I have a 58 and a 61, and the reach is actually longer on the former because of steeper angles and shorter headtube. It took longer to get used to the 58 because of the bigger drop to handlebars, but now I prefer it for most rides. As others have said, the size you end up depends on the bike's geometry, your fitness, riding style, and so on, but at 6' I would start at a 58 and consider working down...

I'm 6'1" and a 60 would be big for me. 58 should be fine, I think...