puma1552

I'm 5'5" (evenly proportioned but with slightly long arms), 40 years old, average flexibility, and have been riding a size 48s Colnago C-RS for 6 years without issue. Absolutely love it, but eye is starting to wander. Trying to do some geometry mapping to a new bike that is largely similar but maybe addresses just the couple small niggles I have. My current bike is very comfortable for very long rides and not cramped; I don't mind being stretched out a tad. Although I'm 40, I'm not ready for something as upright as a Roubaix or similar. Not much to complain about with the bike's fit but the niggles/notes are:

1) Drops reach is good but hands fall naturally about 1 cm back from ideal hood position - would like 1 cm less effective top tube; already on an 80 mm stem, don't want to go to a 70 mm. Factory stem was 90 mm.
2) Not a huge deal, but pushing the limit for stand over height (I can stand over with the top tube right there; I never unclip both feet though and likely wouldn't with a smaller frame anyway).
3) Currently have 25 mm of spacers, but I could easily lose either one 10 mm spacer or the 5 mm spacer and be fine. I am basically a french fit but being stretched out a bit, I'm not really that upright.

Basically I love the fit and handling of my bike, I just wish the ETT was 1 cm shorter and being a touch easier to stand over may as well be something I fix with the next bike while I'm at it.

Here's a chart comparing my current bike to some key measurements on a couple replacement options:



My thoughts:

V4Rs:
1) 485 - ETT is way too long, that size is out.
2) 420 - might be cramped, not sure. Likely use a longer stem than 80 mm to compensate for shorter ETT. Surely better stand over but possible toe overlap? Stack getting too low = too many spacers needed?
3) 455 - looks right? Minimal stack reduction while giving me exactly 1 cm less ETT, which should put my hands right on the hoods naturally with the same 80 mm stem (the stem/bars are integrated on V4Rs and the 80 mm stem models come with 75 mm drops reach, which is perfect. 90+ mm stems have 80 mm drops reach). Little more seat post would show too and probably slightly better stand over.

V3Rs/V3:
1) 48s - basically identical to current bike, could obviously work but result would be the same.
2) 42s - might be cramped, not sure. Likely use a longer stem than 80 mm to compensate for shorter ETT. Surely better stand over but possible toe overlap? Stack getting too low = too many spacers needed?
3) 45s - looks right? Probably at the limit of acceptable stack reduction; gives me a little over 1 cm less ETT. Little more seat post would show too and probably slightly better stand over.

Conclusion:
With the main goal really being just a bit less ETT and with slightly easier stand over being a nice to have, I think either a 455 V4Rs or a 45s V3Rs/V3 would fit me well while being comfortable and not cramped, assuming the same 80 mm, -6 degree stem. But I really can't tell if the 420/42s sizes are too small or if those would actually be the right size with longer stems compared to the 455/45s? I don't like my bike too cramped/twitchy, nor do I like toe overlap, which I currently get none of. I don't find 80 mm stems to be twitchy, because I'm a bit stretched out currently and have a slack head tube. My only experience with a cramped bike was a 49 cm Allez test ride, which I found to be awful (I realize it's a crit bike and a poor comparison being an off the shelf test ride, but I hated the feeling of it being so small under me and hitting my toes on the front wheel).

Thoughts?

DaveSSS 

I'm 66 inches or 168vm tall, with long legs. My saddle height is 72-73cm. I had a C-RS in a 48cn with no spacers and a -17 x100 mm stem to produce an 11cm saddle to bar drop.

​​​​I'd say you need the smallest 42cm.

If you can remove spacers, try that.

FWIW, with my saddle height, I also have two bikes with only a 505mm stack height. The minimum headset top cap is 20mm and the bars are integrated with -6 degree angle that raises the bars about 15mm. Don't overlook stem angle.

Iride01 

You won't know if you like other types of fit if you don't try them out.

I picked the smaller of the size overlap I was in for my Tarmac. And I don't feel cramped on it. I wish I'd considered even the next smaller size just outside the two recommended. Except then the frame stack may have gotten too low and I'd have to keep all the spacers under the stem that possibly would fit.

You should think of twitchy as sporty. Sporty being more maneuverable in close quarters such as riding with others that might stop or turn suddenly in front of you. Or get around potholes they don't call out for you or simply escape your attention when you are solo.

If the twitchy feeling is just something you are feeling while trying out the bike for a ride or two, then realize that in almost every case it's just something you get use too as you get use to the proper inputs to make with your muscles. Might take a week or two worth of rides.

puma1552

Thanks. Just curious though -

You're only 1" taller than me and also had the same 48, but are recommending a 42? Did you feel your 48 was a bit too large?

My saddle height is 82-82.5cm from the center of the pedal spindle (guessing you used center of the crank to measure instead which I think would put your saddle 6-7cm higher than mine which makes sense if you have really long legs). What I find interesting though is that even with the extra 6-7cm saddle height you still had a 20mm longer stem slammed -17 degrees and no spacers...all that added up seems like it would make a significantly longer reach to the hoods than me with my 25mm spacers and 80mm -6 degree stem, and especially considering that while my legs/torso are approximately proportionate, my armspan is like 2" wider than my height, so my arms are considered kinda long I believe and I still don't have a cockpit as long as yours. Obviously you're an inch taller, but it seems like your torso would be shorter than mine given your seriously long legs so I'm having trouble visualizing how your reach to the cockpit wouldn't need to be even shorter than mine. Do you have super long arms and super flexibility?

I'm basically a french fit with just a few cm of saddle to bar drop and average flexibility, and I'm 40. Regardless of going to a smaller frame size which might show more seat post, the actual saddle to bar drop is unlikely to change much overall except maybe a couple extra cm.

Sorry, not necessarily disagreeing with your recommendation for a 42 - you may well be right - I'm just having a bit of a hard time visualizing how long your reach is on the same size/model of bike given you're only 1" taller than me and all of that and maybe more is in your legs.

For a visual, this is how my bike is set up:

Iride01 

Which is roughly the amount of spacers you have under the stem on your bike pictured. If you take those spacers out from under the stem, it might give you a idea what the smaller size bike might feel like for more bar drop. Not so much for the difference in reach. But at least you'll know what that much drop will feel like. Saddle height is the one thing that will stay the same between any road bike model or size in the same model that you pick. Bar height will only get lower with decreasing sizes that generally decrease the frame stack too. There is only so much steerer tube the bike will come with that you can get over that.

I don't know if on new bikes they shorten the steerer tube to a certain exposed length as the head tube length decreases with size, before sending them out to the LBS or customer. On the size bikes I look at, they generally come with about 30-40 mm of spacers in varying size thicknesses. Maybe another knows.

wheelreason

Smaller frame with more stack.

Polaris OBark

The Bike Geometry Comparison Tool website might be worth a look.

SoSmellyAir

puma1552: You want (a) your reach to the hoods to decrease by 10 mm, but how is (b) your reach to the handlebar tops? If the latter is fine, then you don't really need a frame with a shorter ETT; you just need a handlebar with less reach and/or to clamp the STI levers a little bit closer to you. Not that I am discouraging new bike shopping in any way.

DaveSSS 

My saddle height from the center of the crank is 72-73cm. That's the most common way to measure it. If I measured to the pedal spindle, that would add 17cm. Even though I'm old, I use a saddle to bar drop that's not much different than a pro cyclist, at 11cm.

Your bike is set up with much less saddle to bar drop and a shorter reach. If you want to try a more aggressive fit, just remove all of the spacers and put them on top of the stem. Every 10mm of spacer removed will also increase the reach by about 3mm. I once removed 20mm of spacer to use none and it caused me no problem. That bike was a small sized LOOK 585.

FWIW, my wingspan is about 2 inches greater than my height.

​​​​​​Your brake hood position looks fine. I wouldn't change it. I use bars with an 80mm reach, which is very common these days.

If you're happy with the fit, an endurance bike with a taller stack height and less reach might be a better choice. Colnago geometry has up to 10mm longer reach than other brands. I used a 100mm stem with my C-RS. My current bikes all have a little shorter reach, so I use 110mm stems with them.
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