Looking through pictures of very old bikes I noticed the saddles, all of them leather like a Brooks, were pushed forward on the rails. This got me thinking about why the Brooks saddles have a reputation of using short rails and many people cannot get them back far enough. This got me thinking about seat tube angle and how it affects placement of the saddle and where on the rails it is clamped.

It dawned on me that the really old bikes used slacker frame angles than today's bikes. The rails on Brooks saddles reflects this design as the saddles can be pushed very forward, but do have a limited rearward position. With this in mind I built a touring frame with a 72 seat tube angle and it allows the saddle to be supported in the middle of the rails. Using a 73 or 74 seat tube angle forces the saddle all the way back.

Has anyone else come to the conclusion that Brooks saddles are better suited on frames with less than 73 degree seat tube angle? Or is this just a bunch of hooey?

Definitely not a bunch of hooey at all.

Which Brooks saddle?
Many styles and rails over the years.

Paved roads changed the need for long wheelbases and slack angles.
Road racing evolved.
Mtn biking revived slack headtube angles.
Too much going on here to generalize.

...
...I always supposed it had something to do with longer top tubes and the resulting farther to the rear position of the seatpost and clamp. I could be wrong. The Asian made Brooks knock offs (like the ones VO used to sell) don't seem to have this issue.

When it comes to saddle fit, I don't think one can generalize. Personally, I've never had a problem with setback and Brooks saddles, but that's my anatomy. I have ridden bikes from the 1930s, and it's not necessarily the seat tube angle that's a factor, but the super slack head tube angle, which creates lots of wheel flop. To counteract, you need to shift your weight forward; hence, the clamp forward saddle position you usually see on those bikes.

For racing bikes with steep seattube angles (track, tri, TT, 'climbing') - you don't see many suspended leather saddles, as there are better designs for 'on the rivet' riding.

For touring or sport bikes where all-out 'on the rivet' riding isn't the deal - suspended leather saddles have a bigger audience.

But the above is generalization. You can ride hard on a suspended leather, you can ride Fred on a narrower harder racing saddle. Saddle design, riding style, body measurements, top tube + head tube lengths, stem/bar characteristics and other factors influence a saddle's clamping position on the rails.

edit: also, a part of the personalization and art of good bicycle fit.

Considering KOPS as the rule for fit, I have two bikes with 74 seat tube angles, one with 73, and another with 72. On the bike with 72 seat tube angle the saddle rails are centered on the seat post clamp using the same seat post as the other two bikes. On those two, the saddle is shoved all the way back, and I still feel the rivets, more so on the 74 than the 73 degree bike.. Brooks Professional saddle, 1979 model year. Same thing happens with a B17, 2018 model year.

That's always been my understanding -- the Brooks design was frozen in amber before frame angles steepened to ~73°, and the switch-over to plastic saddles among performance cyclists took away any evolutionary pressure on Brooks to keep up with the times.

Quite frankly, as much as I like the Brooks shape, I'd use something else (maybe Berthoud) if I had any frames that had seat tubes steeper than 73°. Even that is pushing it for me!

This conversation is eye-opening. I'll have to go look at where I have mine on the rails!

Okay, so, in a word, yes. Brooks saddles use a frame design that was developed many decades ago, when bikes tended to have relatively slack seat tube geometry.

But that's not all there is to it.

Brooks saddles are designed to have a rather pronounced Y-shape, as opposed to other designs that have more of a V-shape. The front ⅓ part of a Brooks saddle is narrow. The wider part of the frame, where you attach the seat post, reaches absolutely as far forward as it can, without making the front part of the saddle wider. So, as a result, you cannot get more setback unless you change the shape of the saddle.

Saddle modifiers, mostly Italian ex-racers (many anonymous ones, plus better known ones including Barale, Galmozzi, and especially Ottusi), who remade Brooks saddles to a new shape, made them more of a V-shape. The Unica-Nitor plastic saddles came a little later, and they too have a relatively V-like shape. That is, the middle part of the saddle is wider, and as a result the wide part of the rail reaches farther forward, and you can get more setback.

Selle Anatomica saddles are really V- shaped, and therefore have a long adjustment area.

I don't know why frame builders think seat tubes have to be steeper, since riders need to overcome this by placing their saddles farther back; perhaps it's a conspiracy against older saddle designs.

Where I put the seat for me is more about the cockpit length and stem length. I am short trunked and long legged, so , the race geometry is very comfortable on my bikes. I do notice that the bikes I have that have stem lengths over 100mm I tend to move my saddle forward on the rails whether it is my Brooks or my Cinelli’s. We are all different in terms of riding habits and those of us that have been riding for many years get used to a certain setting and , for me , hard to think about changing unless it becomes uncomfortable. The other most important setting is seat angle. I usually spend a lot of time getting that right as after about 30 miles I get really sore if it ain’t right. Joe

The rails on a Berthoud Aspin aren't any longer than the rails on a B.17, although the shape does let you sit a little farther back on the saddle. Your best bet to deal with a steep seat tube angle is a Nitto S84 seat post.

Kabuki12, am I corre t in understanding that you do not concern yourself with KOPs, just the distance from the saddle to the handlebar?

Ah, shoot! I'd probably select a different frame before going to a wild-offset seat post.

The Brooks Campagnolo edition saddle that used narrow rails and special seat post rail clamps had a longer fore/aft adjustment length.
I don't know who brought those two mfgs together, Bianchi? Legnano?

There was an evolution in thinking of saddle position before the framebuilders caught up. Before steeper seat tube angles there were 7 seat posts which had a horizontal tube allowing the saddle to be moved forward.

the UCI has a say in this too- at least for international level racing bikes.
it has diverged from one number but for road bikes the forward point of the saddle is to be at least 50 mm behind the bottom bracket. In review there may have been a clarification about the useful seating part of the saddle positioned to that dimension via appeal.

this type forming was to prevent recumbents and later "tri bikes" from polluting the peloton.

for a long period seatposts or posts and clamps placed the attachment point of a saddle behind the seat post. - or no more forward of the centerline- now called a setback seatpost.

Some of us can’t just “select a different frame”! Although if I had budget, space, and the blessings of my cyclist wife, a custom frame would have a shallow ST.
My asymmetric rear demands a leather saddle (love my Berthouds!) if I want to be comfortable for more than 30 miles, and my long legs like it set well back. Here are my “wild-offset seat posts”. And yes, Berthoud saddles allow one to sit farther aft without actually sitting on rivets as on Brooks of my experience (Team Pro, B17, Swift).

Early version of VO’s long setback seat post (only comes in 27.2mm) on the Marinoni, showing my asymmetry:


Truvativ 26.8mm in Miyata 912, which also has since gotten a Berthoud:

BTW, that Ti-railed Rivet Independence saddle on the 912 has a bit more setback than a Brooks, and is no longer in use...

Sorry if I offended, [MENTION=340794]Dfrost[/MENTION]. If I'm judging anyone, it's bike makers who won't accommodate all riders, not the riders themselves!

I am not sure what KOP is but for me yes the important thing in my seat position is distance to handlebar. Of course overall comfort as far as myarse is imperative , but the short distance to myhandlebars feels best on long rides. I did about 25 miles today on my Medici that has a short to medium reach stem and the saddle is positioned aft of center on its rails . The saddle is a Cinelli UniCanitor . This is why I like racing bikes over touring bikes, for my long legs and short trunk , it works. Joe ps I find the same goes for my Brooks Pro saddles.