The perfect Seat Tube Angle

Wondering if everyone here has drunk the Koolaid with regards to steep STA? 

My Primer is my steepest STA at 76 degres not-sagged. I put a new seat on today and figured I'd try it further forwards on the rails. I hated it for everything except riding up steep road. On technical sections I found I felt perched on top of the bike and had too much weight on my hands and lost maneuverability. I struggled with all the tight corners and slippery roots. I figured it was because I was post call but mid ride I slammed the seat back and voila, I was riding like a champ again. I also found it rubbed my legs uncomfortably while descending. When I put it back, the seat got out of the way when dropped rather than having the fattest part of the saddle right between my knees.

For me, I think 74-75 degress is the sweet spot. On really steep ass climbs I have to really get low or out of the saddle but the bike handles better for me overall. Wondering what STA you all actually prefer?

As seat angles get steeper I think it is to obtain a longer reach but keep the top tube lengths about the same. But as you noticed doing that can cause you to have more pressure on the bars. To alleviate that you can raise the bar height but that results in a more upright position which isn’t as efficient for pedalling. Or you can move your cleats as far back as you can or feet back on flats. Or move the seat back. You see some unusual saddle angles on steep bikes like Pole. I think that may be because the rider is leaning so hard on the bars that they are sliding back on the saddle so an extreme nose down helps. I’d have numb hands and sore shoulders i I did that. The so called efficiency of a steep seat angle on full suspension is partly to take into account more rear sag and even more rear sag when pointed uphill but at least part of the solution for taller riders is longer chainstays. Steep seat tube angles on a hardtail is just fucking stupid.

On a HT the STA gets steeper with sag and on a FS bike it gets slacker with sag so there is no way to pick a number unless you specify what kind of bike. After that it really matters if it's a winch and plummet bike or a bike you ride in the saddle on flatter/rolling terrain a decent amount. And we really need to be clear if we are talking about the effective STA measured at saddle height or the geo chart STA which is not the same unless the bike has a straight seattube.

On my 140mm hardtail that gets ridden for long distances as well as for shredding something like 74-75 deg effective STA works for me. I've been riding MTBs ~30 years so sliding forward on the saddle for a minute or 3 on a super steep climb doesn't cause me any grief.

Have you considered that it only seems like kool-aid to you because you're happy with what's always been on offer. 

I have a 36" inseam and bike companies until recently refused to vary chainstay lengths or seat tube angles by size. So when I was up to pedalling height I was basically flipping over backwards on climbs. Every single bike I've owned for 30 years has been like this. Until now. My new bike has 450mm chainstays and a 79' ESTA that puts me in a great climbing position even on steeps. This is the first FS bike I've ever had that was correct. 

Peoples' STA/ESTA preference is hugely dependent on height, inseam, femur vs tib-fib length and a bunch of other factors. Calling it kool-aid oversimplifies this to basically right and wrong, which is awfully convenient for someone who can comfortably ride what's always been available.

YMMV, I run my seats slightly nose high and all the way forward, which would effectively steepen the seat angle

unless the seat is tilted funny I don't see how where you put the seat would thro weight on the hands ?

It’s about seated balance. It can be subtle but it’s there. Stand in front of a table a few feet back and lean on the edge with your hands out butt over your feet. You are leaning with weight on your hands.  You’ll fall forward if you try and take your hands off the table unless you move your butt back.

Posted by: XXX_er

unless the seat is tilted funny I don't see how where you put the seat would thro weight on the hands ?

As you move the saddle forward relative to the BB and leave the bars in place you are putting more weight onto your hands.

Posted by: Vikb

On a HT the STA gets steeper with sag and on a FS bike it gets slacker with sag

This. The 76 degree seat angle on my Rootdown (same geometry as Primer) feels steeper than the 77 degree seat angle on my Sight. Also, differences in actual seat angle can result in an effective seat angle at your saddle height that is different from what is on the geometry chart.

Posted by: andy-eunson

It’s about seated balance. It can be subtle but it’s there. Stand in front of a table a few feet back and lean on the edge with your hands out butt over your feet. You are leaning with weight on your hands. You’ll fall forward if you try and take your hands off the table unless you move your butt back.

I can take my hands off the table without falling forward or moving my butt.

I put a building level on the seat and tilt it so the end above the stem is 1" higher than level which feels very right for me,

I tried flat saddle on the new road bike cuz i read somewhere you are suposed to have a seat flat but I didnt like it

so I went back to nose high, the road coach told me my position on the bike looked a lot better with the saddle like that ... YMMV

Posted by: RAHrider

.....

For me, I think 74-75 degress is the sweet spot. On really steep ass climbs I have to really get low or out of the saddle but the bike handles better for me overall. Wondering what STA you all actually prefer?

Trouble is the published seat angles tend to be fiction, written by marketing I imagine.

Crop a bunch of catalogue pictures along the BB axis and look how far the saddle is from the edge of the picture. Interesting how far off the numbers seem to be . (Obviously not as accurate as physically measuring the bikes with an angle finder and level or plumb line).

It's funny reading lazy reviewers complain about the "slack" seat angle of such and such bike and extol the "steep" angle of another, then cropping the catalogue pictures yourself and seeing they appear to be identical on both bikes.

Most mainstream bikes appear to be pretty close to identical lately as far as I can tell, whatever that actual angle is. There are a few outliers I've seen though like Revel which is slacker, and Norco and Marin which are steeper.

As far as my preference, unless I'm riding flat or rolling ground (I slide back on the saddle for the road commute to the trail) a steep angle is definitely more comfortable and faster for me while climbing the trail.

Posted by: Hepcat

Trouble is the published seat angles tend to be fiction, written by marketing I imagine.

Unless it's a straight seattube starting from the BB the geo chart STA will be measured at some arbitrary saddle height that is not likely to be the same as the rider's. Often this height is selected as level with the top of the headtube....which is low vs. actual riding position for most people. I wouldn't go so far as to say geo chart STA are fiction/marketing/made up, but they are 1) not likely to be what you will experience riding and 2) frequently the methodology varies between companies so you have to be careful comparing two geo chart STAs. It's quite possible to that Bike A has a slacker geo chart STA than Bike B, but when you are riding both Bike A has the steeper effective STA for you.

When I said I thought 74-75 deg worked well on my 140mm HT I was talking an effective STA that I measured at my actual saddle height and taking into account how I had positioned the saddle rails in the seatpost clamp.

My fully 75.4 still climbing the nose steep pitchs. >77 seems too extreme somehows.

https://geometrygeeks.bike/

Posted by: Vikb

...

When I said I thought 74-75 deg worked well on my 140mm HT I was talking an effective STA that I measured at my actual saddle height and taking into account how I had positioned the saddle rails in the seatpost clamp.

Ah, this is interesting. You may be the only one here who's measured their seat angle properly and knows an actual number.

I have no idea what the actual seat angle I prefer is. I rode a "73.5° angle" bike and "75.5° angle" bike that we measured out with a plumb line to be identical setback, which felt a little slack. I also rode a "74°" and "76°" recently which had identical plumb line setbacks after pushing the saddle forward 2mm on the 74. Whatever angle that was is spot on for me. But the ideal number those bike were could actually be 70° or 80° for all I know.

Yeah I agree, measuring this vital metric level with the bars is next to useless. Industry needs a more sensible measuring standard.