CIVEbike

Hiyo,
I've been riding a 54 cm. Miyata 310 that has a very tight road geometry where as I am 5'9 with a 29" inseam, so short legs and a long torso. I feel like my butt should be further back so my back can straighten out. Also, on rides longer than 10 miles or so my lower back tends to hurt and standing over the bike I have to be up on my toes.

I'm in the market for a new (old) steel frame, preferably something that would fit me better and is japanese or italian made from the 70s or 80s. Does anyone know of a companys that made bikes with a somewhat unusually long top tube? I'm having trouble finding information on old bike geometries. I'd like to use it for much longer rides ~50-100 miles, and getting around the city.

Thanks!

Grand Bois

Bridgestones had long toptubes. Maybe you can find an RB-1 or RB-2 that isn't ridiculously overpriced.

See item #320011117658 on eBay. Sixteen hours to go and no bids. Maybe you can snag it cheap.

John E

As one who has owned and ridden lots of road bikes from the 1960s and 1970s, I can assure you that, for a given seat tube length, a European top tube will tend to be longer than its Japanese counterpart. You may find that a 54cm Bianchi or Peugeot fits you perfectly.

CIVEbike

Thanks, I have been noticing that japanese top tubes tend to be shorter. I'll also keep an eye out for bridgestones.

Pompiere

With my Miyata 310, I had the opposite problem. I am 5'9" with a 32" inseam so I have a 58cm frame and I was experienceing lower back pain from being too stretched out. When I switched to a shorter stem, riding became much more comfortable. Maybe if you swapped to a longer stem, you could stretch out more. I went from a 100 or 110mm down to a 60mm extension. My decision on length was based on the thumb-rule of the front axle being hidden by the handlebar. I just laid a ruler on the bar and sighted down to the axle to see how much change was required. Either I got lucky or the thumb-rule really works, but it's been 20 years and I'm not changing it.

John E

Even though my 23" / 58.5cm C-T Nishiki was too tall for me, its top tube was so short that I was much happier when I installed the long-reach stock stem from a 25" Nishiki. In contrast, I had to put a minimum reach stem on my 57cm Peugeot PKN-10 to obtain a reasonable fit.

The traditional rule of thumb is that with your elbow against the nose of the saddle, your fingertips should just touch the back of the horizontal center portion of the handlebar, next to the stem, i.e., the stem-to-handlebar distance should be one cubit. Most of my bikes are about 5-10mm longer than this, but most folks may prefer a somewhat shorter distance.

cyclotoine

Of the bikes that I have seen the European ones tended to have shorter top tubes. I have a 58cm carlton with a 56cm top tube.. seemed short, I know a guy who is looking for a Binachi with a 60cm seattube and 56cm top tube. He claims they are out there. In terms of small bikes. My girlfriend rides a 50cm and a 52cm. The 50cm is a GIOS with a very short top tube I think it is squared up but it replaced a 50cm fiori (Norco-japanese made) which had a 53 cm top tube she liked the GIOS position better (same stem). Her 52cm Norco Magnum GT has a top tube longer than 53cm for sure and she just looks too stretched out on it. I have come across low-end apollos (made by kuwahara) in a 52cm with a 57cm top tube! However I think things vary more in small sizes. ALmost all my 62cm frames have 58cm top tube except the marinoni (59) and the Raleigh team pro (57).

John E

It is evidently a function of frame size and year of manufacture. I can speak only from my own experience, in which a 1980 57cm Peugeot PKN-10 and even a 1970 54cm Peugeot UO-8 had significantly longer top tubes than a 1971 58.5cm American Eagle Semi-Pro.

I am noticing the same phenomenon in mountain bikes; my 1988 Schwinn has a significantly longer top tube than my circa 1992 Ross MT-1600.