What's with the seat clamp in front of the post?
 

I've noticed old bike catalogs usually show bicycles with the seat clamp set in front of the seat post.
http://www.sheldonbrown.com/retroral...an-drawing.jpg

This is just about always the case on bikes with upright handlebars, and often (or usually) the case on bikes with drop bars.
http://www.sheldonbrown.com/retroral...ton-sports.jpg

Today, of course, we always put the seat clamp on the back of the post, or use a seat post with an integrated clamp that always goes to the back. Actually, I'm not even sure it would be possible to use a typical "modern" post this way ("backwards") (has anyone tried?).

And it would appear that il campionissimo had his 1952 Bianchi set up like a modern one (though of course it may have been changed later):
http://www.rouleur.cc/images/stories...e/img_1318.jpg

So I'm wondering, were the older bikes designed for a different weight distribution than today's? Does anyone ride this way today? I'm especially curious about those of you who ride bikes from the 50's and earlier.

Actually, it makes more sense from a structural standpoint. Most of your weight goes through your "sit bones" which (for me at least) settle in at about the widest part of the seat. Putting the clamp that way positions the sit bone contact point directly over the seatpost. Doing it the "modern" way is more aesthetically pleasing to our eyes, but it ends up meaning the load is further aft of the seatpost and the seat has to carry higher bending load along with the vertical load. The old pictures are correct from a structural efficiency standpoint, but it looks dorky to us today.

http://www.ravingbikefiend.com/bikepics/reg09new3.jpg

I think it has always been about fit... my Reg Harris model has a long top tube and those bars have some pretty good extension (I have some decent reach).

In a time when frame sizes were more limited to 1 inch increments reversing the seatpost just allowed the rider a greater range of adjustment... I never see this as being backwards on older bikes.

We should also know that Reg did a great deal of his road training on a fixed gear... :)

I have thought of reversing my clamp but that would be to meet an aesthetic as the bike is perfectly dialled in... I would do it for science.

Really? I'm having a hard time conceptualizing how the orientation of the clamp would affect how weight was distributed; the seat would stay in the same relative position over the post, no? Otherwise it'd affect fit.

Maybe I'm just confused about what is being talked about.

Another thing that I forgot to mention: the old seat post bags fit much better if the seat is farther forward.

Sixty Fiver, I can't tell from the photo; but you have your clamp in front of the post? Beautiful bike, anyway.

No. Assuming the clamp attaches to the rails at the same spot, then having the clamp in in front of the post puts it about 2" forward of where it would be if the clamp is behind the post. The length of the rails on your typical saddle allow for about 1 1/2" of adjustment.

http://www.ravingbikefiend.com/bikepics/regnew1.jpg
1955 Raleigh Lenton Sports Reg Harris Road Model

This what a Lenton looks like it after it has been ridden continuously for nearly 60 years... :)

I had things set up for more upright touring when I took this shot but have lowered and levelled my bars a little since... I have a new Brooks clamp for the bike and I will install it reversed.

I've got some modern bikes and some vintage bikes, and the only one with the seatpost clamp facing forward it my Airborne Manhattan Project, which you can see below. Everything else has the bolt at the back.

http://i705.photobucket.com/albums/w...t/IMG_1093.jpg

Ok, looking back at the pictures, I understand what you're talking about.

Was about to write a big ol' paragraph about not understanding the structural argument still, but then it all clicked. I wasthinking it'd put you further behind the clamp than the modern way, then realized that would probably put you right over the seat tube, which is exactly what doohickie was talking about (i think).

The seat tubes on older bikes were between 68 and 70 degrees as opposed to 73 to 75 for modern bikes. As the seat tubes got steeper the clamp rotated around the back to keep the seat in the same position.

vjp

No, you misunderstand me. I'm talking about the seat clamp, which holds the seat to the post, not the seat post clamp that holds the seat post in the bike frame. Thanks for your photo; it shows a typical modern post with integral clamp on the back of the post.

We have a winner!

I follow you now...I was thinking of the wrong clamp.

Okay, but is that the whole story?

I've also read/heard that it was a function of a slack seat tube angle. No zero-set-back posts in the old days!

Neal