emeshelman

I'm in the market for a vintage road bike to use as a commuter. I'm 5'11", generally in the 56-58cm range I'd imagine, but every vintage I stumble on in that realm seems too small. Is that normal, do you generally size up for vintage? Reach seems shorter and more compact, and my legs always seem too close to my torso. This weekend in particular, I tested a 56cm 1982 Austro Daimler Puch Luzern Reynolds 531 and a 58cm 1986? Trek 310, both of which felt far too small.

For reference, I'm used to a 56cm 2012 Specialized Roubaix. My stem is not slammed--it's quite the opposite, as I've taken it on multiple 3-4k mile excursions so preferred the upright feel. But my saddle is aggressively high, much higher than these vintage seatposts give.

horatio 

Is the stem on your Roubaix slammed?

emeshelman

Updated ending of original post with this information--thank you for the question.

bikemig 

It's easy enough to add a longer seatpost if that's the only thing that bugged you about those frames. At your height, you likely can fit 56-60 cm with 58 likely being the best size. The point is that whatever riding position you have on your current bike can be replicated more or less on a vintage bike.

ramzilla

You can always raise a seatpost on a small frame bike. But, you can't always lower a seatpost past a certain point on a large frame bike.

crandress 

If your Roubaix is has a 56cm seat tube, you would need something larger in a vintage bike because vintage bikes don't have a sloping top tube. If the bike is what Specialized refers to as a 56 (which has a seat tube much shorter than 56cm), then you should be close as it is meant to be the equivalent of a traditional 56cm frame. I would think you would not need a bike bigger than 58cm, but there are many variables including your leg length. A good shop should be able to help you find the right fit though for any style bike. Also dependent on your riding style one would think. It could just feel funny because you are positioned differently.

Salamandrine 

If you are comparing modern sloping top tube bike sizing to vintage steel, you can't. Yeah, you have to size up, likely about 4 or 5 cm. Modern bikes have a sloping top tube (usually), and more seatpost exposed.

One way to get your vintage size would to lay a level on top of the top tube at the head tube joint, and then measure from the bottom bracket center to the bottom of the level along the seat tube.

Or just get your ballpark size the old fashioned way, by standing over a bike. Lift up both wheels evenly to get top tube clearance. Circa 1982, you'd have wanted about 1.5".

Sounds like you are pretty long legged. You may be best with something as large as a 60 or so, with a relatively short top tube. Only you can find out.

horatio 

I'd try a 60cm frame and see if the longer top tube doesn't feel better, but it's not uncommon to find a 60cm seat tube mated to a 58cm top tube, like my Ciocc. In that case you'd need a longer stem to stretch out.

T-Mar

In my experience, the SBI road frames of this era were sized based on effective size for a theoretically horizontal top tube. A Roubaix with a 56cm size had a true length seat tube of only 51.5cm (CTT) and an effective horizontal top tube length of 56.5cm. This would be very close to my starting point for an average proportioned male that is 5'11", which would be a 56cm or 58cm frame.

horatio 

Here's the scoop on geometry. @T-Mar, you are dead on, as usual.

horatio 

OP, a pic of your bike from the drive side would help.

emeshelman

Thank you to everyone who provided input--this is exceedingly helpful, pretty much confirming I'd need to play around with larger sizing (thought I was going crazy on my own thinking about this). I'll just have to keep trying on Craigslist until I find something that feels right. And to the whole Specialized sizing, I ALSO thought I was losing it because I know I have the 56cm and I certainly wasn't measuring 56cm... Haha Thanks again!

philbob57

1) Size of vintage frame measurement - CTC or CTT? 54 cm CTC is about 56.5 cm CTT. IIRC, the Treks are measured and advertised CTT; I don't know about the Puchs.

2) A rule of thumb for frame sizing BITD was 9"-10" less than you 'inseam' - but was that 'cycling inseam' or 'pants inseam.' I bought bikes based on pants inseam, and got a bike that was too small.

3) IIRC, some manufacturers produced non-custom frames with 22" top tubes. Works great for me, with my relatively shorter legs and longer torso and/or arms and 21" seat tube. Might won't work great for other sizes and proportions.

4) The 1"-2" clearance rule doesn't take into account the rider's weight. Should someone buy clearance to flesh, or clearance to bone? I'm ...um... fleshy. I bought clearance to bone, and I'm OK with that.

5) Feeding my measurements into Competitive Cyclist's tool, I got 50 cm for the most competitve fit. Man, I rode a 50 cm Gitane for a a few years BITD and almost gave up cycling. The new bikes are almost square, and i think the Gitane was, too - I felt too cramped. Today's fit doesn't suit me, but it's what vendors sell. The y used to sell a different fit. Who knows which is better, and who knows what is best? Beats me....

Giuanin

Bernard Thévenet and Phil Anderson, 1.80m / 5'11"as you, used frames of 57cm ctc.

easyupbug 

Might be worth looking into https://www.competitivecyclist.com/S...ulatorBike.jsp. It is easy to do and might point out some aspects of your sizing that would helpful. They also have a good discussion on French Fit vs. a more competitive fit which you may have on your Roubaix.

Classtime 

I get it. Some vintage frames that are "my size" have seat posts that are a bit short for my preferred saddle height. I rode my PX-10 with the saddle about 1cm short and the stock simplex post extended as far as I dare. I did the same with a Tenax Schwinn. These experiences make me think that BITD, if you needed more leg extension, you got the next size larger frame and not just a longer seat pin. For a while the long campy post was 180mm.

ryansu

Something else to consider is that even with the same seat tube length e.g. 58cm the TT can vary widely on vintage bikes. I have some bikes that are "square" 58 cm st and tt but others have shorter tt or longer. The good news is you get to test out a wide variety of bikes to find what fits. When I found something that finally felt right I took careful measurements of tt st standover, saddle height, reach of seat post to bars and stem height and length so I could replicate the fit down the road. Have fun test riding until you find the fit you want.

SurferRosa

"I see your Schwinn is as big as mine. Now let's see how well you handle it..."

- Dark Helmet [alt take]

Salamandrine 

I can answer a couple of these.

1) CTT was pretty much standard for all typical bike shop lines of bikes. CTC was very rare, usually Italian racing bikes IIRC.
2) never heard that one but doesn't sound too reliable.
4) There is a correct answer to this. It's to the bone. Ignore the flesh. We would have to sort of politely ask customers to lift the bike up vigorously, as far as it will go, to get the correct measurement. Could be slightly awkward.

Wildwood 

edit: missed @ryansu's comment above. but confirming.



Sizing can be weird, period.
I have 62cm (ctc) bikes with top tube lengths ranging from 59.5cm down to 54.5.
Go figure.
Luckily, stems go to 140mm, some seatposts offer seatback.
But it is confusing/challenging at times.