Vintage frame fit

[dirttorpedo]

About three years ago - after years of mountain biking - I got back into road riding by buying an aluminum GT Edge off Craigslist. Well I was completely clueless about how a road bike should fit and ended up with a 54cm x 54 cm bike (I'm 6' 1"). Thinking that bike was a 56 cm frame I replaced it with a 58 x 58 cm GT Edge in steel. The fits ok, but because I have a very short stem on it (80mm) I suspect I should have gone with a 57 x 57 cm or a 58 x 56 cm frame. Anyhow, I'm shopping for an early 80's road bike to add to my collection. This bike would probably be my winter training bike and also be the bike I used to ride L'Eroica if I'm so lucky to tick that off my bucket list. Now I recall my old 80's road bike frame to be quite large - like 24 inches or thereabouts. My GT would convert to around 23 inches in the old sizing method. So what should I look for? A 24in x 23in, a 23 in x 22 in? a 22in x 22 in a 23in x 23 in?

FWIW my PBH is around 32 inches.

 

[Jonny69]

From what I've observed, 80mm isn't short for a stem on old frames, it's more like the norm unless you specifically wanted a longer one. It's only since threadless headsets have been used that stems have got longer. An old 58cm frame is probably about right for you - I think a 56 will feel a bit small.

 

[Johnsqual]

Re:

+1 to Johnny69.

Like you, I'm about 6'1" (183cm) and I under-estimated my frame size when I bought my first road bike. I was riding round on 56cm frames, both modern and retro.

For various reasons, I recently re-thought my bike fit and used a few different online calculators to recalculate my size. This one was quite good because it takes a lot of information and gives guidance on stem length and other stuff, not just frame size:

http://www.competitivecyclist.com/Store ... e.jsp#type

I came out with 59cm frame size. My commuter bike is 58cm.

One of the guys in my club pointed out my saddle was too low, so I recalculated that using the 109% of inseam, measured from pedal axle to top of seat method.

Riding a bigger bike with the saddle height set right does feel more comfortable and efficient, and the knee pain problems I was having have become much better.

Johnny

 

[dirttorpedo]

Re:

Interesting. I have a fair bit of hand numbness riding my 58 x 58 with the 80mm stem which is why I thought the frame might be too big. I ride with the bars up high and have a nitto noodle on the bike with brifters. Would a 58 x 56 be more suited to me? Should I get a short reach handlebar? Dump the brifters and go to downtube shifters and regular levers?

 

[NeilM]

Re:

I can't comment on vintage bike fit, but on my 90's retro frame, my 2004 Rourke and my new KTM I ride 56 / 57 and I am 6' 1".

I don't do the mega mileages some guys do, but I regularly ride 60 to 70k and this summer have done a couple of sportives, one 70k the other a touch under 100k and have had no issues with the fit of my bikes.

That said, fit is very personal, and what fits one tall guy may be murder for another, as typified by my son and I, who are both similar heights, but who have measurably different fits, although we both ride 56cm frames.

 

[47p2]

I'm 5'7" and my 1985 frame is a 56cm x 56cm so the OP definitely requires something bigger

 

[dirttorpedo]

Re:

I've been perusing the 1981 Trek catalog (I'd like to get an old Trek) and noticed that I've been misinterpreting the imperial frame sizes. I thought the 22 1/2 inch frames equated to 57 cm, the 23 inch to 58 and the 24 inch to 60 but its not so straight forward. A 22 1/2 inch 1981 Trek is actually a 56 cm frame and the 24 inch is just a titch under 60 cm. That's probably why I remembered riding a 24 inch bike in my youth.

 

[cce]

%ft 10 and riding 57cm top tubes here.

 

[dirttorpedo]

A fellow selling an 80's Koga Miyata tells me that top tube of his 60 cm frame is 56.5 cm long which would put it in my size range with respect to reach. Did these older bikes have lower bottom brackets than frames made in the 90's like my GT?