mschwett 

long story, but i need to replace a bike i love with a different one. i've ridden about 10k miles on the white bike outline below, had it professionally fitted and it's great. it's a 58. if anything, i would have guessed it's maybe 1-1.5cm too "small" in reach for me, since the saddle is slightly farther back rather than farther fore, but it fits great. i'm a hair under 6'2, average proportion arms and legs.

the rub is that the two largest sizes of the new one, 56 and 58, both have shorter reach but quite a lot higher stack. it looks to me like the 56 is actually closer to what i'd like, with the only meaningful difference being that i'd need a 20mm longer stem (so a 130, pushing it?) to get the touch points in the same position. 10mm less toe clearance, not worried about that. the actual difference in reach from white to dark blue is 17mm. no worries at all that i could get the saddle to BB position just right with any of these.




FWIW, the manufacturers calculator/recommender says to go with the 56 for a sporty ride or 58 for comfortable, so i'm obv on the edge. i also dislike the way the larger frame looks.

it just seems crazy that someone 6'2 would ride a 56. shop also said these run big. and no, there is nowhere anywhere nearby with the bike on the floor in either size.

choddo

I would always go smaller. I’m 6’2 and that meant getting the 58cm instead of 60 version of my bike funnily enough. Rarely, I clip the bars with my knee when out of the saddle. Which would be solved by your longer stem but wasn’t an option for me, integrated headset/bars. Apart from that, correct decision.

PeteHski

It’s actually quite common for pro cyclists to downsize for a lower stack height and they just compensate for reach with a long stem. Same as you are thinking. It should work fine.

DaveSSS 

If you know the current bike's stack, reach and seat tube angle, comparing it to a new one is fairly simple. Stack heights often have a 20mm difference between sizes. To compare the two correctly, assume that 20mm more steering tube spacer will be used on the smaller size and subtract 6mm from its reach, then compare the two reach values. Seat tube angle only affects the seat post setback that may be required. Each degree of difference changes the seat post clamp horizontal position by about 12mm.

Stem angle can be used to change the bar height too, if the bike doesn't use a proprietary integrated bar/stem with no stem angle options. With integrated bars, getting the right stack height is more critical, to avoid a big stack of spacers.

I pay no attention to frame size numbers or letters. If the stack on the new frames is a lot taller, you may be comparing new endurance models to an older racing model. If you want lower stack, a different frame model may be needed.

Iride01 

Comparing frame reach can help pick which bikes to look at, but you also have to take into account the stem length and bar reach. As well if the seat post has a set back or not. So all of those bikes could be made to give you the same position. Though you probably should get the one that will require the least changing out of parts.

Be wary of all the things a geometry comparison tool doesn't show you. Length of cranks probably changes too between 58 and 56 cm frames. Stem length might also change by 10 mm or so. The bar width might have 2 cm difference also.

I like shorter cranks and narrower bars and lower bar height so I'd be taking the smaller frame size. If you prefer longer cranks and wider bars then take the larger.

You really won't know till you've ridden one or both for a long distance. If you can't do that, then consider the return policy of where you are buying.

bruce19

Back in the day it was common to get the smaller size because it would be lighter. I'm feeling pretty lucky because a 54/55 frame with a 55 TT is perfect for me. If frames are specified as S-M-L I make sure I take actual measurements before I choose a frame size.

DaveSSS 

I haven't bought a pre-built bike in over 30 years. I much prefer to buy a frame and build it up with my favorite components. The already built bikes that I've looked usually have bars that are too wide, a stem too short, a saddle that I don't want and tires and wheels that I'd replace.

My next bike may be a true road bike with electric assist, like those by Orbea or BMC. They both have the problems mentioned. Pay a lot for the bike, then pay more to replace a bunch parts.

choddo

Doesn’t that end up costing a lot more?

mschwett 

orbea is one of the more customizable ones in that space - others you literally have no choices other than size, and any components you change you just eat. it’s too bad, but understandable given what a niche market it is.

interestingly you can buy just a frameset (including motor, battery, controller) for some of the higher end eMTB, so it’s certainly doable.

eduskator

I'm 6'2'' and ride 56cm or 58cm depending on the frame's geo. Looking at the picture you posted, I'd get the new smaller one for sure. You can always compensate the handlebar reach by changing your stem for a longer one.

wheelreason

"I like the way the larger one fits but not the way it looks" is a thing with a lot of guys (it's always guys). I've read your post 3 times, and still not sure what you are asking, and I do this for a living...

Zaskar

I TOTALLY get the looks thing. It shouldn't matter, but it does. I hated the look of my 62 - it looked like I borrowed it from an NBA player. My next bike was a 58. I was able to replicate my fit with a bit more post showing and a slightly longer stem. It was the best of both worlds. I now have four 58s and they all feel fantastic. Oh... and they look good too ;-)

mschwett 

weirdly, everyone else figured it out? another way to say it is “is a 20mm longer stem to compensate for 20mm shorter reach on a new frame going to screw anything up?”

the consensus seems to be no, and that the proposed size is close enough to a current bike that i know and like as to be viable.

mschwett 

of course it matters! not more than fitting correctly, but it’s a downer to look at something with unpleasant proportions. unfortunately a lot of bikes with tall headtubes just don’t look good to me.

PeteHski

Yeah, there’s a reason why all bikes pictured on manufacturer websites are medium sized. They just look better proportioned. XL frames nearly always look terrible. 58s usually look ok, but above that they start looking odd.

aliasfox

If the bike you're trading up from is running mechanical (non-hydraulic) brakes, one more thing to consider with fit is that hydraulic hoods are noticeably longer than cable brake hoods. Might make the difference between a longer vs shorter stem. Conversely, if going from a 'standard' sized handlebar to a compact handlebar, you may actually lose ~10mm in effective reach - or vice versa if going the other way around. I would add those two factors into the equation as well. If the touchpoints remain comparable (ie, hydraulic to hydraulic, compact bar to compact bar), then the conversation can stay focused on frame and stem.

Of course, this is also predicated on whether you can get comparable stack heights between the bikes. With ~30mm of allowance for spacers, that generally shouldn't be an issue going between two adjacent sizes.

One thing in favor of the smaller frame size would be having slightly more exposed seatpost. If you buy into the comfort that an unsupported aluminium or carbon tube can give you, than an extra 2cm of exposed post might feel better (psychologically, if not physically).

Or you can find a Bianchi, which will split the difference with a 57cm size, solving your issue (why does Bianchi do odd-numbered sizing, when the rest of the industry goes even?)

tomato coupe

No, it made you look like an NBA player.

jimincalif

My bike is a 59, I’m about 6’ 1”. When shopping, the LBS owner who is about the same size suggested the 56, as that’s what he prefers. I tried it, but it did have a toe overlap/strike issue, I took it on a 50 mile road ride, but still didn’t care for the toe strike, even though it wasn’t an issue when actually riding. But this is also a gravel bike, so I had to consider occasional low speed turns with more turning of the front wheel than it typical on the road. So I chose the larger size.

Zaskar

I'm just under 6'1" but my legs are ridiculously long - hence being fitted on a 61cm (twice)... so, I looked like a normal dude riding some big dude's bike.

Turnin_Wrenches

mschwett : If it were me I'd go with the smaller frame (which seems to be the consensus from reading prior comments). If you need a 130mm stem to get you to your preferred reach, that's OK. It's at the long end of the spectrum, but not out of the norm.

I think one important piece of info that was not provided in your original post is the type of riding you do. If you are a racer and/or enjoy fast group rides on curvy roads, the smaller frame will have more lively and nimble handling. The smaller frame will also have a lower stack, which will help get you into a more aggressive / aero position. If you're more of an endurance, long-distance cyclist, the larger frame will be more stable with its longer wheel base, but also less nimble and less lively (relatively speaking). The taller stack may also help with comfort depending on your level of flexibility.

vuurmot

definitely smaller so you can build up if necessary
just go for a bike fit honestly

Camilo

Probably yes. But, the expense is mitigated or even negated by the number of parts you happen to have on hand for the build, and the number of parts that come on the ready made bike that you'd need to or want to replace due to inadequate fit parts, saddle, gearing, and especially, the wheels that almost always come on a ready-made bike that aren't commensurate with the overall quality you'd expect for that particular bike. For me, it's a combination of these factors that leads me to building a bike up from the frame. I haven't bought a complete bike for my wife or myself for a long, long time (8 or 9 bikes over the years?) until recently when i bought two inexpensive Salsa Journeyers to be kept with our RV away from home. (FWIW, they're "cheap" but very functional and plenty fun).

But I like messing with them, and making them exactly how I or my wife wants and needs them to be.

PeteHski

The wheels are usually in line with the overall build tier level chosen. It’s only a problem if you want to pair a low tier group set with high-end wheels. Even then it’s often cheaper just to buy an additional wheelset or a higher spec complete build if the difference in cost is less than the wheel set.