[Closed] Has modern bike geometry forgotten pedalling efficiency?

I find current designs far more efficient feeling, I was forever trying to balance getting the saddle forward for efficiency against trying to keep stretched out enough.

Go and ride a Charge Blender about a bit then report back.

If you ride up hills, I think you'll find the steeper seat tube a pleasant surprise - as long as you haven't sized down obvs!

What does tend to get overlooked these days in the focus on progressive geometry, is how efficiently full sus bikes pedal. Most are OK, but some are really good and a few are soggy and bob-prone.

If you value pedal efficiency, be sure to get a test ride on your planned purchase. Which may also address your seat angle concern anyway.

The steeper seat angle + the usually pedal efficient design nowadays makes climbing easier and offsets the general increase in weight of modern bikes. Suits the climb up and smash descents sort of riding very well.

I get that saddle forward improves bike stability on steep climbs and descents which is good if that is the type of riding you do. If you riding is undulating flat (like mine), then the leg power and knee health is more important. Paton's vid was interesting but a little confusing. Forward like Chris Hoy, but do not let the knee pass the pedal spindle. Seems to be a balance which requires a bit of testing on the bike.

I've read that it's less comfortable pedalling on the flat, but the kind of bike you are talking about is all about winching up to allow you to plummet down. There are other bikes, designed for pedalling efficiently, perhaps you could get one of those? They aren't anywhere near as compromised on descents as people seem to think.

I find current designs far more efficient feeling

Agree with this. I went from a large MK1 Bird Aeris 140mm travel which was ok to a XL 160mm LongShot Cotic Rocket which feels a million times better on the climbs despite being steel and more travel. As already said steeper SA are key (well for me any way) keeps you more central in the bike making it easier on techy climbs.

In terms of Fore and Aft I think the thing to remember is the majority of us are not elite athletes so just stick the thing flat and in the middle and go from there. Extreme changes in the seat position will never end well incremental over time is whats required unless you got a jig.

Go and ride a Charge Blender about a bit then report back.

So agree with this. By far one of the most fun but most useless bikes I have ever owned. Being over 6ft riding that thing even for 5miles was a struggle.

To the Op's original question and making my own frames I'd say yes.

The current steep sa fad came about because the long reach and slack ha needed it to work. There was a by-product that the steep sa / long back end was easier to make (no need for complicated shaping of seat tube, rear stays, bb area and more room for wheel travel on full sus). So the manufacturers can upsell a "feature" that actually makes their life cheaper and easier. And everyone buys new bikes with wondergeo tm.

For non winch-plummet riding, I've settled on unfashionable slack / short rear end and a moderately long / moderately slack front end. This works fine, and if I need more front wheel weight I just slide forward on the saddle (so have many options on seated position during a ride). You can't do the opposite and slide backwards on a steep sa.

Does this not break the tried and tested bike set up rules (front of knee over pedal spindle), which I assume have been developed with best efficiency and knee health in mind?

The KOPS thing is nonsense. I'm surprised anyone still takes it seriously.

https://www.sheldonbrown.com/kops.html

It's also to counter the sag of the rear shock when sat on it. So a classic seat tube angle would be even more laid back while a steeper seat tube would settle at a more natural angle...
Climb switches dont truly lock out shocks.

double post

^ What thols2 said.

I've always preferred a straight seatpost and saddle rammed forward long before steeper STA became common.
Using bodyweight to push down onto the pedals instead of pushing down/forwards always felt better to me.

I’ve read that it’s less comfortable pedalling on the flat, but the kind of bike you are talking about is all about winching up to allow you to plummet down. There are other bikes, designed for pedalling efficiently, perhaps you could get one of those? They aren’t anywhere near as compromised on descents as people seem to think.

This all day. The majority of the bikes we're seeing bought and sold on here lately are what the people 'want' which is bikes that go down better than they go up, it's all about the down. Sure, they go uphill, but not quite as well as full on XC weapons... But that's the price for going down better.

Knee over pedal is pseudo science passed down by generations of roadies.

Steep STA on a full suspension is needed because when seated you sag into the rear travel more than front and it slackens the STA.

The new generation of hardtails with STA as steep as FS bikes could be going too far as they get steeper when you get on the bike with front sag only. I can only think the purpose is so you can make the bike as long as possible for standing descending while retaining a comfortable ETT when seated.

Geometry is not seen as a science, more what companies think looks acceptable and what it fashionable at the time. The likes of Geometron pushed DH geometry for specific purpose of going downhill, then they found it actually works just as well for everything else.

I think the thing to remember is the majority of us are not elite athletes

I really don't think it matters if we're elite or not. Why should our bikes be uncomfortable or inefficient just because we're not pros? I may not be racing but I'm still sat in the saddle for three hours giving it my all and getting tired, and I'd like to feel as quick and comfortable as I can be.

I have been wondering the same. i think it depends what you want the bike for. I understand the steep SA gives good climbing thing and the idea behind winch up and hammer down - but if you plan longer rides and 'days out in the hills' then it may not work so well although some of the Bikepacking.com guys who claim to know about these things seem to love the steep SAs for bikepacking bikes.

I am not so sure as the general feeling is that slacker seat angles move your body back and provides a better weight distribution between bum and hands with your feet on pedals acting as the fulcrum. Steeper angles tend to push your wight onto your hands which can be uncomfortable. My most comfy bike for all day riding has a slack SA. I would like to try some steeper angle bikes to see what works - but I suspect that i would only use one for shorter rides and trails.

There are other bikes, designed for pedalling efficiently, perhaps you could get one of those?

Agree. A slack bike with steep seat angle is built for a purpose. That purpose is not to churn out the miles on flat terrain.

For the original question - no.
They’ve optimised pedalling efficiency for seated climbing. Rotate your bike backwards to simulate it going up even a modest climb, set the rear sag to 30%+, and the forks to 0sag, and then see how steep the seat angle is relative to the pedals.
The trade off for this is on the flat road you are in a sub optimal position, this seems to have been accepted by most bikes of the larger travel variety to be beneficial.
Most fit people who ride bikes I’d wager could get a modern enduro bike up to its top pedalable speed (probably just over 20mph with 32x10) for a short period of time even while in a sub optimal position, probably without even using their full strength.
However, get on a climb, and suddenly being able to put 10% more power means you are climbing 10% faster (approximately).
It a really noticeable when you are riding with your mates, looking at your Strava time or a reviewer who has to answer the question ‘how does it climb’ but never the question ‘how does it feel ridingdown a flat road’

Remember that the knee over pedal nonsense also goes hand-in-hand with "Ball of big toe over pedal axle" nonsense.

Myself, and everyone I know personally rides with either/or/both:

- Cleats slammed as far back in their clipless shoes as possible
- Flat pedals with arch of foot over pedal.

Thats gotta be equivalent to 20-50mm of saddle fore-aft movement.

The legs are making the same shape, but the whole body (and CofG) isfar further forward and 'in' the wheelbase of the bike, not dangling over the back axle.

Timely thread as I'm having issues with this too.

KOPS=bollox, although its somewhere to start from I guess.

I'm running a MkV Soul with 140mm forks and a last gen (2) Rocket Max (both med). The Soul by my standard is a steep (but effective) SA, and is the best technical climbing bike I've owned. The Rocket Max, I basically feel wedged between the saddle and the bars, even with the saddle all the way back on the rails. Its great for plodding up steep fireroads - lazy sit there and spin away stuff, but as soon as I have to stand up to climb, either for a technical uphill section where I need to chuck the bike around, or a short down section, I'm basically unable to move about without dropping the saddle, which if it's in the middle of a lung buster is the last thing I want to do, as I'll just blow up (and possibly loop out) trying to push the saddle down.

On the flat I do notice that I've got quite a lot of weight on my wrists too on the Rocket as my upper body is pushed further forwards over the bars, despite the reach being longer. The bike is absolutely the right size for descending on (and an absolute riot to ride) - I really wouldn't want to size up, but it does limit how big a day I want to do on it, whereas the Soul I just don't really fatigue on. (the Rocket also plays merry hell with my hip flexors and glutes as its such a different shape to all my other bikes)

The daft thing is that the most recent Cotic droplink bikes have yet steeper SA again (and is why I deliberately opted for the older frame)

Like all these things, the only way you find out where the limits are is by pushing too far and backing off a bit. There was a thread earlier this week about shorter TTs and narrower bars. Plus tyres seem to not be a thing anymore, a few years ago it was all about how low you could get the bars on your DH bike - now that's all stabilised. We're probably hitting the point now where "peak steep SA" has been reached and a lot of manufacturers might back off a hair

Will I be pushing the saddle back on the rails or swapping in a layback seatpost, to get back to where I used to be?

No, because the bike is very likely to be longer up front to allow you to keep the same length cockpit, just shunted forwards overall. Saddle goes forwards, but so do the bars.

I’ve read that it’s less comfortable pedalling on the flat, but the kind of bike you are talking about is all about winching up to allow you to plummet down.

IMO this is a consequence of bars still being too low. We dont need them to be so low anymore because weight distribution is improved as per my above comment. Everyone still seems to be learning this bit.

Nobody pedals these days, you just coast down hill from the uplift surely?

Most fit people who ride bikes I’d wager could get a modern enduro bike up to its top pedalable speed (probably just over 20mph with 32×10) for a short period of time even while in a sub optimal position, probably without even using their full strength.
However, get on a climb, and suddenly being able to put 10% more power means you are climbing 10% faster (approximately).

Not even close to top speed ... on a 32T front on 27.5 I keep an average 30 kph on our local mostly flat roads. (simply cos I've got komoot in kph*) and that's not even using the 11T
How knackering or not that is depends on tyres above all else.

*setting it in km and kph makes me feel better...

Also 30kph just seems to be fast enough to get to the trails without dying of complete boredom

but do not let the knee pass the pedal spindle

or what will happen?

Your knees might hurt

I have tried the below bikes over the last year around the tweed valley and I have gone back to my Capra 2018CF. About a week spent with each bike.

Norco Optic
Norco Sight
Privateer 161
Bronson
Megatower
Ransom Tuned
Rocket
Rocket Max.
DMR SLED (better than all above ride feel wise and in steep terrain, never got tired or sore on it. Easy to ride. IMO)

Who cares about pedalling efficiency?

It's all about the downs.

Your knees might hurt

Any evidence for that?

Sounds like the same bro science oft quoted for squatting (with no scienece to back it up).

Steve - I think I’m agreeing with you.

Top practical speed is what I’ve called the sensible limit of riding your mountain bike on flat tarmac.

A single ring trail or enduro bike is going to give you a practical speed limit in the low 20s (in freedom units) without spinning like a loon or totally exhausting yourself.
People seem to be happy with this speed at a moderate level of exertion. (And let’s be honest, it’s a lot more effort for little gain at higher speeds with knobbly tires and an upright position).

If you had a 40 tooth up front would you really have the want or ability to do it significantly faster? Outside of elite level xc races that situation doesn’t really arise.
The need to use your maximum power happens when you are seated and the bike is pointed up a steep slope, or you are stood up and sprinting downhill. For which modern geo is much better suited.

Not even close to top speed … on a 32T front on 27.5 I keep an average 30 kph on our local mostly flat roads. (simply cos I’ve got komoot in kph*) and that’s not even using the 11T

Unless my maths is incorrect*, and assuming you are using a 13T sprocket and 650x 2.25" tyres, and not taking into account how draggy those tyres are, you must have a cadence of over 90RPM. You are Chris Froome and I'm claiming my £5!

*my maths being incorrect is entirely possible!

KOPS is a good starting point and knees may hurt if saddle dramatically too far back or forward but that is down to the individual. It does have a bearing on muscle use though so while may not affect knees it will affect how fatigue the muscles are.

This is all really based on road riding though going at a fast speed for a long time and not just riding up a hill sitting down, coasting back down standing up etc,.

Steve – I think I’m agreeing with you.

Yep...

the sensible limit of riding your mountain bike on flat tarmac.

Unless my maths is incorrect*, and assuming you are using a 13T sprocket and 650x 2.25″ tyres, and not taking into account how draggy those tyres are, you must have a cadence of over 90RPM.

Quite probably correct (seems about right for me)... though my smallest tyres will be a bit bigger... something around high 80's to 90 seems the most comfortable for me on tarmac/gravel etc. and Komoot is probably not that accurate GPS speed??? (It's just an indicated speed I can keep up for a few miles/km till I get to the trails ... I find unless I set a speed and keep to it I'd very quickly be doing about half that.

People use maximum power in all kinds of terrain and situations - not just your examples of steep climbs and stood up sprinting downhill. Modern geo is not fastest for everything.

I bought a Ripley frame over the summer and have been having this same thought. I couldn't get the saddle back to match my previous bikes. I couldn't get the saddle height right either, for whatever reason it was always too high or too low.
After a two month wait I got a 9point8 layback dropper and a 35mm stem (from 50mm). I tried this combo with the saddle as far back as possible, still not as far as previously.
It felt awful, and I was contemplating selling the frame. But I did some digging on the interweb and found two articles that set me on a new path...
https://www.mtbiking.com.au/how-to/bike-tech/cockpit-setup
And
https://m.pinkbike.com/news/lee-mccormacks-guide-to-perfect-bike-set-up.html
I think the rad thing has been mentioned before on singletrack.
So I forgot about saddle position in relation to BB, and went for a bar to saddle distance instead. Kept the 35mm stem and brought the saddle forward, but also dropped the height. Finally I pulled my cleats back from ball of foot over axle by about 15mm.
Having tried it a couple of times the difference is amazing. I can understand the way the geometry has been designed and love riding the bike. I have done a 4 hour ride like this and not noticed any drop in leg output or new discomforts. In fact shoulders and neck have felt less fatigued.
My advice is don't be obsessed with keeping the same old position, the new way could be better for you. It's an expensive experiment though, I'll give you that.

Oddly, I find "modern" geometry OK on teh flat as long as I am hammering along with my shoulders forward to get my weight over the pedal when I am pushing it. The problem is when I want to pootle and sit up a bit - I can't because the handlebars are too far away.

I take the point made above about higher handlebars, but I like them the height they are for most other types of riding and my available steerer tube was dictated by the guy I bought teh forks off.

I was just reading about the Stif Squatch. 78° seat tube on an unsagged hardtail! I cannot imagine riding that on flat or flowing singletrack. Or on the way to the winch and plummet place. It's probably good on the downs though.

It's like you need an old school XC with a 69° headtube and 73° seattube for singletrack and riding anywhere and then a gnardtail for the plummet.

Buy an ebike and then it doesn't really matter

Pedalling efficiency is one metric in bike performance, i still see lots of bikes that are built around pedalling efficiency, but they are shorter travel and more XC bias, because that market pushes that, the end you're looking at is pushing plush trail/enduro style riding that can minimise small bump impacts whilst still soaking up larger impacts, but in most instances that means more active suspension and rider position being more aggressive.

So the answer is no, they haven't forgotten pedal efficiency, they just prioritise the frame geoemtry for the task at hand, and thankfully so, instead of the old days where the geo stayed pretty similar across the range, only really moving with the DH beasts.

Don’t know about the science but I went from a 2016 Orange Segment to a 2020 Orange Stage 5 so similar in general feel and design. The Stage is a bit longer, lower, slacker and has a noticeably steeper seat tube which puts me in a much more natural and efficient feeling seated position. Defo climbs better, isn’t any less comfortable on the flat and is probably a bit quicker down. I’m sold on steep seat tubes.

Apart from the better climbing position, steeper seat angles are one way to open up hip angle leading to greater efficiency while pedalling and less risk of knee problems. I've not really got any bikes with very steep seat angles by modern standards, but did go through a few with stupidly slack ones. Seemed to put a lot of strain on my IT band and be a partial cause of knee problems.

There are still many suspension bikes with a steep effective seat angle on paper that in reality isn't radical at all. Bent/offset seat tubes get slacker the higher the saddle is, some companies measure the effective angle lower than normal saddle height for the frame size, suspension sag slackens it as well.

Also as mentioned above, the popularity of flat pedals and ramming cleats all the back (me) recently has an effect here, pushing feet forwards. A more traditional seat angle was probably intended to be used in conjunction with the roadie belief in placing cleats further to the front.

i like the steep seat angle on my suspension bike. i think it’s 76 or 77°. it climbs well and though i don’t do long rides on flat trails, it is good on rolling terrain.

i found the extra weight on the wrists from the a steep seat angle can be relieved by raising the bars without any negative effects on the handling.

The current steep sa fad came about because the long reach and slack ha needed it to work. There was a by-product that the steep sa / long back end was easier to make (no need for complicated shaping of seat tube, rear stays, bb area and more room for wheel travel on full sus). So the manufacturers can upsell a “feature” that actually makes their life cheaper and easier.

when long reach and slack head angles came along bike designers were aiming (and riders clamouring) for the shortest rear centre possible and seat angles were still slack and made slacker from massively curved seat tubes. i’m not saying that your opinion on fit and performance or cost to manufacture aren’t valid, but my experience (in the places i ride) tells me that with the exception of wheelies and manuals slack, long, steep and long bikes are great.

Modern geometry is slightly less efficient but that's because there world has realised that making something as efficient as possible takes a huge amount of joy, comfort and useability out of said thing.

The same reason I don't have the absolute most efficient car, football boots, tent or coffee machine.

Current cycling geometry is led by what consumers want rather than what bike designers think is best in theory on paper. These Internet has allowed people to share feedback, ideas and innovation that works bringing the best design by smaller more creative companies to the fore.

An example is Bird. They wouldn't be nearly as successful without the webternet. It allowance them to compete on an equal footing. I'm looking for a new 29 FS and I'm certainly going on forums ahead of reviews.

Surely recumbents are the most efficient peddling position as you are pushing against a solid stop - the seat back not just against your weight and whatever pull you can get on the bars.

The whole KOPS thing is such obvious nonsense as the same peddling position can be rotated backwards and forwards without changing the relative position of bars to seat to pedals

Oddly, I find “modern” geometry OK on teh flat as long as I am hammering along with my shoulders forward to get my weight over the pedal when I am pushing it. The problem is when I want to pootle and sit up a bit – I can’t because the handlebars are too far away.

I'm not that bothered over reasons... but my experience is I either maintain a speed or it drops right off. I guess the reason I'm not that bothered over the why's is the solution seems easy.

I have an old school XC HT as well and the main difference I find is in the intermediate speeds between pootle to pushing on.

Oddly, I find “modern” geometry OK on teh flat as long as I am hammering along with my shoulders forward to get my weight over the pedal when I am pushing it. The problem is when I want to pootle and sit up a bit – I can’t because the handlebars are too far away.

A valid point which I have also found. Modern bikes are far more comfortable when ridden hard. Uncomfortable, poorly handling (and dull) when pootling.

Bit of a double whammy when you get near the end of a big ride and run out of energy though! Riding ability and enjoyment drops off a cliff.

You try pedalling a recumbant up any sort of slope then.
I've found that going from a very layback position [thudbuster /Inbred' to a 75 Big Dog] that, although I have raised the handlebars a lot, I still get more wrist pain. Out of the saddle I only just clear the saddle nose, and that's with the saddle rammed back. So I wouldn't buy a frame with a seat angle of more than 75, preferably 74, because I climb a lot out of the saddle. I have a very very short torso so I'm not averagely proportioned. Overall I like the new position though.
Folks get wound up by the numbers but modern dropper inline posts steepen the seat angle. One can still move the saddle rails which is perhaps a 2 or more degree difference either way

As a tall person, the steep seat angle has been a massive improvement over older bikes. A few years ago my weight was over the back axle and applying any sort of force to he pedals made the front want to lift up.

New bikes with a steeper seat tube and more reach mean I and not cramped and my weight is far more central on the bike making climbing a lot easier, even with more rear travel than I had before.

I don't think it is just down to the seat angle. The modern geometry overall is a big improvement climbing technical tracks, but then the Big Dog like the Solaris has long chainstays; on a short chainstay bike seat angle may be more relevant. Depends in part on how much the overall longer wheelbase is affecting things..