Very confused about riding position(s) - mtb vs road

[2manyoranges]

It felt REALLY weird putting 165 on the mmmBop for the first time. My knees did not forgive me the first three or four rides. But then two things happened…my knees actually changed - lots of side muscle development around the knee and development at the bottom of my quads, and I habituated higher cadence. It was a very intrusive and conscious thing….which lasted only a few rides….now I just don’t notice the difference when switching from bike to bike. Of course, I switch also from 26 to 27.5 and 29…and they feel very different anyway…and all that’s habituated now too.…the human brain is pretty amazing. I was cranking up an incline at the weekend, and I just remembered what a ‘double everest’ female cyclist said last week -‘… it’s just my mind which is making me think I am at the limit, my body can go on…’ and the MOMENT I thought that I could crank more easily and with more power, just as I was slowing up….very interesting, the Human Mind….

 

[eightyeight]

I'm 175cm with an inside leg of a little over 33" (because we love mixing metric and imperial). I've run 170, 172.5 and 175 on different bikes and never noticed the difference but perhaps that's just me.
Different bikes makes sense, track bikes tend to be 165-170 due to banking rather than rider size, i think you just get used to it and develop for it much as 2manyoranges says.

 

[rochester21]

Hi guys,

This is a sort of rambling/monologue on some thoughts that have been keeping my brain busy this last week. I recently switched back to riding a MTB (1993 Marin Palisades Trail ) in the city, for commuting. It wasn't much of a voluntary decision. My main bike broke down and I had to make do with what I had. Two things surprised me: the first is that over a 20km commute in London, the mtb is only 7% slower than my road bike. I was expecting worse. The other is how much more comfortable I am pedaling on it, compared again to the road bike which, for sake of information is a modern Boardman SLR8.6. And I don't mean comfortable riding position, but comfortable leg movement. I feel that my legs move more naturally and that the effort is distribute across the leg muscles, while when I'm on the Boardman, the effort is mostly on the quads. What's worse is that on the road bike there seem to be a perfect window in cadence where the pedaling feels good, but as soon as I need to grind or spin, it feels either very hard or uncoordinated. With the MTB I have much more flexibility and don't have to be in the perfect gear all the time.

I will take some time over the weekend to compare the riding positions, especially the horizontal distance between saddle and bottom bracket, as I suspect I might be too far forward on the road bike. Which would be a shame as the seat is fully slammed back. I might also consider a professional fitting on the bike, but before doing that I would like to try to understand by myself what's going on.

Somewhat true, but then again a road race bike isn't built with comfort in mind, it's a racing bike.

There is however a solution, buy a endurance road frame with a compact handlebar and raise it using spacers and a stem with pozitive angle.
This way you will have a more upright position.

It's the same when buying a motorcycle, a cruiser is very different that a racing machine.

If you don't race, simply buy something with a more relaxed geometry.
But that's advanced biking stuff, in the beginning people don't realise how important fitting and geometry can be.

 

[Madmax1993]

But that doesn't answer the question. If none of them are sufficiently right, you've got no baseline.
And it sounds like the Boardman isn't right anyway, short legs/long torso *usually* requires a long stem to get the stretch right, not slamming the saddle all the way back.
You really need to get someone to cast an eye over it all.

This.
I see so many people using the saddle position to get closer to, or further from the bars. The saddle position is meant to get you in the right place over the pedals (plumb line from the front of the knee through the pedal axle when pedals are at 3 o'clock position IIRC).
Then you adjust the reach of the bike with longer or shorter stem, or flipping the stem between 'rise' and 'drop' positions. For the reach you want your bicep at 90° to your torso, and a slight bend in the elbow, all when holding the 'hoods' of the shifter.


If you get things right, your road bike should be fairly comfortable, as the boardman has a more endurance geometry, not an aggressive race geometry.

 

[eightyeight]

That stuff about knee over pedal spindle is bollox. How does that work on a recumbent?
90% of bike fit is from what position you are used to riding in. Anyone who has specific rules for a bike fit is probably doing it wrong, we are all different.

 

[Madmax1993]

That stuff about knee over pedal spindle is bollox. How does that work on a recumbent?
90% of bike fit is from what position you are used to riding in. Anyone who has specific rules for a bike fit is probably doing it wrong, we are all different.

I'm not sure about a recumbent, but I would take a guess and say, the same applies, just rotated back by 90°, so a spirit level through the knee and pedal axle. Or that a recumbent being what it is, requires sacrificing the perfect position for the needs of a recumbent rider.
We are all different, yes, but that doesn't make certain 'rules' of bike fitting wrong. Regardless of shape or size, if your saddle is too low, you'll get sore knees. If your seat is too high, you'll get sore hips. So yes, everyone's body is different, and different settings are required to position them correctly.

 

[eightyeight]

So if it can be rotated for a recumbent can't it be rotated for any bike/seat tube combination?
Bike fit, body position, arm position etc. etc. depend not just on rider but the type of riding they are doing too which is why 'rules' are often unhelpful, they can get taken out of context.
The knee is often above the spindle but that doesn't mean it should be. If you have a fit that is good for you and the knee isn't directly above the pedal spindle don't change just so it is.

 

[Madmax1993]

So if it can be rotated for a recumbent can't it be rotated for any bike/seat tube combination?
Bike fit, body position, arm position etc. etc. depend not just on rider but the type of riding they are doing too which is why 'rules' are often unhelpful, they can get taken out of context.
The knee is often above the spindle but that doesn't mean it should be. If you have a fit that is good for you and the knee isn't directly above the pedal spindle don't change just so it is.

The rotation of the whole system where the cyclist is effectively lying back is not the same as a rider being at the same angle just horizontally shifted over the pedals. The second is not a rotation, it's a change of relative position.
As for different types of riding, of course the rules don't always stand up. A modern trail/enduro MTB has a really steep seat angle, which will throw off the 'rule' we are discussing, in order to position the rider better for 'winching' up a hill. It's sacrificing one bit of efficiency in favour of something else.
The rule does give the most efficient pedalling position when in the saddle, on a road or XC bike, which is what the OP has. Small variances are one thing, but as others have pointed out, the OP has shown pictures of different bikes with very extreme (visible in a photo) positions that are very unlikely to be comfortable for anyone.
I would start by resetting to this neutral position, and work from there.
Anecdotally, people usually come away from a bike fit feeling more comfortable, and realising that their way felt comfortable when it's all they've ever known, but was subject to improvement by someone with knowledge and experience.
But by all means, choose ignorance, choose to believe that you know better than science.

 

[eightyeight]

When you show me the science i will become a believer but when all you show is tradition and opinion I'll remain doubtful.

 

[Woz]

You would all do well to read this: https://www.clinicalbikefit.com/dispelling-the-myth-of-kops-keith-bontrager/