[Closed] Steeper seat angles

In theory, what does a steeper seat angle do?

In practice, they generally let you keep up over the cranks on steep climbs so it's easier to pedal. There will be a limit to this, though. Inline seatposts aren't unusual, XC racers have been using them for decades.

One very basic thing, which I think is quite often overlooked when people talk about it, is it means the seating position doesn't change as much with the height of the seat. With, say, a 73 degree seat angle an extra 100mm of seatpost means moving the seat about 30mm further back. So within the range you can compensate with different seatpost heads or moving the saddle, provided you're not using that for something else.

I had a Scandal 26 with On One Approved 130mm fork and 400mm seatpost and I ended up say somewhere behind the rear wheel 🙂

With the long and slack revolution many manufacturers overlook the seat angle which is a vital component in the geometry. As well as the above stated benefits it’s also means that you can remain centered on the bike both while descending and climbing. Throw is a short stem and you no longer have a wandering front end whilst climbing.

In summary lengthen and slacken the frame then shorten the cockpit to compensate the doown sides.

People think that everything has gone long and slack now but in reality very few bikes are truly long and slack, the rest are just slightly less conservative than last year.

My Patriot has a slack seat angle by modern standards.  An unexpected side effect of this is that I found it surprisingly hard to pick the bike up to pop off small trail obstacles when using flats, since my feet are far out in front and I it's harder to grip the pedals by angling feet downwards.

As a taller rider I'm delighted. I can spend less time looking at the other fashion variable of shorter seat stays since a steeper seat tube won't see my bum somewhere over the rear axle with the seat up.

it’s also means that you can remain centered on the bike both while descending

Not really, why would you be descending sitting down?

Looking at pictures of the bike’s OEM buil I see it comes with an inline seatpost.  Given that they aren’t typical these days, looks like someone at Trek had a similar idea.

Aren't they?  Look at all the dropper posts most of us now use.

An unexpected side effect of this is that I found it surprisingly hard to pick the bike up to pop off small trail obstacles when using flats, since my feet are far out in front and I it’s harder to grip the pedals by angling feet downwards

you do that "popping off" while sitting on the saddle ?

I'm sure there is an effect on handling while climbing, but the reality is that your seat should be set in relation to the BB, in height and setback to get in the right position for pedaling, obviously if pedaling is what you are trying to get optimize.

So I don't understand the whole thing where a steeper seat tube angle will move you forward on the bike it you set your saddle up correctly?

So I don’t understand the whole thing where a steeper seat tube angle will move you forward on the bike it you set your saddle up correctly?

loads of bikes are too slack (plus coming with a layback post) to actually allow you to setup in the correct position for pedalling efficiency

So I don’t understand the whole thing where a steeper seat tube angle will move you forward on the bike it you set your saddle up correctly?

Never hauled yourself forward and almost stuck the nose of the saddle up your bum for a steep climb?  Steep seat angles mean you are forward already where old school shallow wouldn't be there even with the saddle all the way forward

you do that “popping off” while sitting on the saddle ?

No - but I'm moving forward from the saddle to do it, and because the cranks are further away I find I have to move forward more.  I'm sitting down and standing up a lot.

In my opinion, slack seat angles have their place.  I think that they are useful on touring bikes and for long days in the saddle as they tend to be comfortable over long distances.  Indeed efficiency is a relative term and for certain types of riding/rider they are efficient.

I like steeper seat angles for steep slippery climbs, going fast on trail centre type rides and similar energetic riding.  Horses for courses innit.

loads of bikes are too slack (plus coming with a layback post) to actually allow you to setup in the correct position for pedalling efficiency

Interested as to why you say that.  Steeper SA feels better to me, but I'm repeatedly told that roadies have done experiments to prove that it is not more efficient to have a steeper SA.

It's simply a by product of increasing reach and needing to maintain a reasonable seat to handlebar distance. A side effect is shifting body weight forward which helps keep the front wheel down when climbing.This has been inflated as meaning 'better climbing' like suddenly it creates 50watts more power.

loads of bikes are too slack (plus coming with a layback post) to actually allow you to setup in the correct position for pedaling efficiency

Funny how roadbikes (where pedaling efficiency seems to be quite important) have seat angles of 72/73degrees and mostly use setback seatposts (TT/Tri bikes are a different matter as its more linked to aerodynamics/utilizing a different muscle group).
Although I'm not a KOPS subscriber (it's more happenstance than scientific fact)  it does seem widely accepted as a starting point for good pedaling dynamics.

I see it comes with an inline seatpost. Given that they aren’t typical these days

Err, yes they are. As mentioned above, have a look at a few dropper post clamps.

I’m repeatedly told that roadies have done experiments to prove that it is not more efficient to have a steeper SA.

By who? And for what?

Steeper seat angles tend to make climbing easier within the parameters of modern MTB geometry.

Try climbing the same section with your saddle pushed all the way back and see what you think.

But is the whole KOPS idea linked to a load more widely accepted geometry norms?  Once you change one of them do others have to change too?  How do recumbent riders manage?

I was pondering about this. I was looking at changing frames and started checking out the Stanton Sherpa & SC Chameleon, but decided the SA was too slack compared to what I ride.
It all goes back to when I had a Charge Blender- HA 68' (slack for its time) and a 66' SA !! It pedaled like an absolute pig. I had similar 4x/DJ/Messing about bikes, but the Blender was by far the worst. From then on I have always considered steeper better.

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Look at it, looks crazy! This was mine. With the saddle up for XC you pretty much sat over the rear axle (yes, saddle angle would be altered for XC rides).

The new 'extreme' geometries like Sick, Geometron and Moxies have 76-77' SA (alongside really long reach & slack HAs).. These bikes are mainly described as winch and plummet, rather than trail bikes. I have yet to ride a bike with such extreme geomtries, but I think a middle ground is required for trail riding.

I'm not far off with my Whytes 'progressive geometry'. I think I want a 76' SA, 435mm reach, 64.5' HA and medium BB drop 29er with adjustable CS.

Err, yes they are. As mentioned above, have a look at a few dropper post clamps.

Not saying they don't exist, more that they aren't the majority.

I'd hazard that they probably are the majority, if you discount BSOs.

Pleased someone mentioned the Charge Blender. Been there done that. Such a fun bike at the time but an absolute dog to pedal.

I find the main benefit of my fashionable seat angle is that I'm in a much more comfortable position 99% of the time and the bike seems to fly along as a result. My last bike was much more sluggish and I travelled everywhere slower even when just pootling around.

A nice off shoot of the steeper angle trend is less wear on the dropper post shaft.

That'd be true if most FS bikes did'nt have offset seat tubes meaning although the effective seat angle is steep the actual seat angle is much slacker.

Plus there doesn't seem to be any consistency on the height at which the effective seat angle gets measured, so you rarely have much idea what your seat angle would be anyway.

legend

Not really, why would you be descending sitting down?

You misunderstand me. I mean that long slack bikes with steep seat angles allow you to remain centered up and down. So when standing for descent you remain centered as apposed to hanging off the back or being thrown out of the front door on a bike that is too short. Then when climbing in a seated position you are still centered by a steep seat angle as apposed to a slacker seat angle that has you too far back, causing the slack head angle to wander and the front end to rise.

You basically sat on the rear axle of my Yelli....it was a HOOT!!

I’d hazard that they probably are the majority, if you discount BSOs.

Alright then - PICS!  Show us your seatposts!

All  droppers bar Command posts and cheapo KS ones (Inline= <10mm).

My X-Fusion has a layback.

Reverb has a little bit of layback, although not much admittedly.

Majority = Greatest number, so the majority of dropper posts are inline FFS.

'I have a black cat.......Therefore all cats are black'

Er yeah I'm not saying that.  But whatever.

What colour IS your cat?

Although I’m not a KOPS subscriber (it’s more happenstance than scientific fact) it does seem widely accepted as a starting point for good pedaling dynamics.

KOPS is nonsense. I didn't think anyone still took it seriously.

This is a Reverb - it is not a layback post:

Pretty much every dropper on the market is inline. Molgrips continues to be a perfect example of the perils of anecdotal evidence.

Steeper seat angles are more efficient for roadies. Take a look here:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786204/

My take is that on modern Enduro winch & plummet type bikes it puts you in a more forward position to aid steep ascents, you'd previously have slid forwards on your 73' SA bike to achieve this. Also, if all other numbers (ETT etc) remain the same you'll gain more reach, thus a more forwards front wheel position to aid the plummets that Enduro riders thrive on. For regular bimblers / traditional XC riders I do wonder if a 77' SA will not be as comfory on long flat / undulating trails, particularly on a HT.

Bear in mind the mantra: if you improve one characteristic on a bike, by design, it'll detract from another characteristic, in the end, it's all a balance.

BX dropper, being not a layback yesterday-

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The last thread on this subject someone pointed out that we're climbing hills on much longer travel bikes than we used to. When you point them uphill the front suspension fully extends, the rear squats. All the super steep seat angle does is put you in the same climbing position you'd have been in on a rigid bike (give or take).

It can lead to some weird characteristics though - I found seated pedalling on the flat very odd on my Geometron.

Echo the point made above about tall people (I always wondered how anyone over six foot ever set up a Klein Palomino, for example).

My current bike is a case in point, built up a month ago based around an early Noughties (?) 21" Kona Lava Dome. In-line seatpost, saddle all the way forward; the contacts are all in the right place relative to each other, but the front end is much lighter and wanders more than the 2012 Cannondale Trail frame it replaced - purely because the seat tube is slacker. I was out yesterday and found myself rediscovering the joys of climbing with my anal sphincter practically clamped round the nose of the saddle. There was a reason people used bar ends back in the day.
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My Patriot has a slack seat angle by modern standards. An unexpected side effect of this is that I found it surprisingly hard to pick the bike up to pop off small trail obstacles when using flats, since my feet are far out in front and I it’s harder to grip the pedals by angling feet downwards.

I'm really, really struggling to get my head around this to be honest. Maybe it's my riding style (or lack of) but I can't think of any instances where I'm 'popping off' things where the relationship between my arse and the saddle is relevant. Because I'm always standing up. Unless I've not managed to get the dropper down.

As above though - it's simple weight distribution - longer travel cpmbined with longer top tubes means you're sat further back, combine that with longer front ends ans slacker HAs and you end up with a more wandery front end that wants to lift as well. Steeper seat angle brings you forward, puts more weight on it, adds a bit of stability, especially on climbs.

With all due respect, Comparing the geo of a Patriot to something like a 65 degree degree HA, 430mm CS, 450mm reach, 160mm bike is very much apples and oranges.

I've been a serial frame-swapper in the past, I can only echo the sentiments made elsewhere about a steeper seat tube angle making for easier climbing.

My current go to bike is an S-Works Enduro, which isn't terribly long in the top tube. The dropper post itself has about 30mm of layback, so I have to perch on the nose of the saddle to climb steep stuff. A 50T cassette helps but it isn't the full answer.

It is a compromise adn will depend on the rider's dimensions and how they like to pedal. Bikes (particularly 29ers) tend to have a bit longer chainstays now than 26" bikes did. On not-so-steep, greasy climbs the problem I have is not getting my weight forward, but getting it back. I have to really push the handlebars away from me and sit up as tall as I can to get grip, or start the rocking back and forth thing. But I like to pedal with my pelvis rotated forward a bit mroe than some peeps (not in proper flat back roadie style, but a bit that way). I don't mind having to slide forward a bit on the saddle on steep climbs, if it makes the riding position on flatter sections better for me.

I found seated pedalling on the flat very odd on my Geometron

I found this on steep tube bikes fine going up but the flat feels like hips are too far forward and my knees are feeling it ( could be age) old hardtail bike I don’t notice

I’m really, really struggling to get my head around this to be honest. Maybe it’s my riding style (or lack of) but I can’t think of any instances where I’m ‘popping off’ things where the relationship between my arse and the saddle

Massive thread revival, but anyway - the issue isn't with my arse and the saddle. The saddle is in the right place with respect the bars for seated pedalling, the issue is that with the slack seat angle the pedals are further forward than I'd like. This means that to get my feet in the right position to pick the bike up as I'd like, I have to move forward, which means that the bars are now a bit too close.

In other words - the distance from saddle to bars is perfect, but the reach is too short.

Since this thread was started, I've realised that I may have been pedalling with my feet too far forward, because I'm really not used to flats. Moving my feet backwards on the pedals is equivalent to adding a degree or so to the seat angle!

I think I'm going to try a slightly longer stem again, and slide the seat even further forward. I've also considered fitting the seatpost backwards to make it lay-forward...

the issue is that with the slack seat angle the pedals are further forward than I’d like. This means that to get my feet in the right position to pick the bike up as I’d like, I have to move forward, which means that the bars are now a bit too close.

?? The seat angle doesn't dictate the pedal position. Even if you changed the seat angle on your bike by a couple of degrees the pedals would be in exactly the same place. If your bars are too close when you stand up its because your reach is too short.

The seat angle doesn’t dictate the pedal position.

Mate the pedals are at the other end of the seat tube from the saddle.

If the saddle.is the right distance from the bars, then a slacker seat angle means the pedals are further forward.

The reach is too short yes that's the point. Shorter reach, slacker seat angle. I'd the seat angle weren't as slack as it is then the saddle would be too close to the bars.