Those with shortened cranks

[Cyril Haearn]

I think we do have many different sets of muscles for different purposes

Cyclists develop some muscles, weightlifter or swimmers or gymnasts develop others

Is the brain a muscle? It comes in many different forms too

[[XAP]Bob]

Yes - but no...

It's not so much different physical muscles (except of course that those in your arms are different from those in my arms) but tolerances and readiness for different contraction regimes.

[recumbentpanda]

On the headwind thing: went into town on some errands during storm Doris or whatever it was called. I Only found out there was anything wrong with the weather when the wind blew my down over the ears Belgian style cap off. Effect on bike handling (Nazca fuego low rider) - zero.

On the safety thing: Every time I get on an upright bike these days, I feel really insecure. During a cold snap, went down on a patch of black ice. Injury to self - slightly scraped dignity. Damage to bike, slight scrape to one side mounted bottle cage and outside edge of a pedal. Yes, traffic can be challenging, but Take The Lane and practice situational awareness. For the most part, I find the 'head up' riding position of most recumbents much better for taking in the road situation that the head down, craned neck of all but the most upright of uprights.

On the short cranks thing: Depends on your leg geometry as much as bike geometry. When I started riding a USS, fairly upright, fairly low BB Linear, on standard cranks, I got knee pain (Muscle attachment points above and below kneecaps). Switched to 155mm cranks and problem went away. Later added pedal spacers which seemed to put feet in a more natural position.

Fuego came with some very nice 175mm cranks with a hollow tech BB that would have been a pain to replace, so decided try them out. NO issues in 2yrs. Maybe my knees just got used to bent riding. Pedal extenders went on new bike too and seemed to improve comfort.

As for the 'elephant in the room' mentioned upthread my reason to ride bents has nothing to do with health issues and everything to do with 'it feels good!'

[BrownBear]

Most of the time (on an upright) I am moving about....climbing, freewheeling, different pace, (slightly) different position. But once a headwind has you pinned down, its an unremitting grind, no chance to lift your bum, stretch your shoulders, you're just pinned there, punching it out. What about on a 'bent? Do you get much chance to move around, or is it a case of repeating exactly the same pedal stroke thousands of times?

Very true and why flat lands are unexpectedly tiring on a df.

There are options for moving slightly in the seat, bridging for hill sprints, having a period of toeing with calves etc. However, overall these are less than on an upright. But it is generally less relevant to bents, since once you have dialled your preferred position, it is so much more comfortable to hold for long periods. What really brings that home to me is static training. I could never do much more than ten minutes upright, but am happy (with headphones) for an hour on a highracer.

[Dave W]

Unusual muscle group for me would appear to be on the front of the thighs (quads I suppose) about two inches above the knees - ache for a couple of days after a good bent ride. DF muscle group seems to be higher up the legs and more to the out sides.

[Dave W]

The White Elephant answer would be 'because they are different' I was kinda hoping it would be 'because they are different and faster' I live in the wrong area for the latter unfortunately.

[landsurfer]

Reading and commenting on this post led me to look into the practical aspects of recumbent trikes.
Are there plans available for a lightweight, home built recumbent trike ?
Single, full-size (700c) wheel at the rear.

[531colin]

Unusual muscle group for me would appear to be on the front of the thighs (quads I suppose) about two inches above the knees - ache for a couple of days after a good bent ride. DF muscle group seems to be higher up the legs and more to the out sides.

Sorry to disappoint those of you who think you have a different set of muscles for every activity, but Quadriceps group consists of 4 muscles.;


from http://www.elitechironw.com/bigger-quads-according-to-science/

Immediately above the kneecap and medial is Vastus Medialis
Lateral, mid-thigh is Vastus lateralis.
are those the ones?

[Dave W]

haven't got a clue. I can tell you where I ache and that's about it. I think riding a recumbent is similar to me to step ups. Possibly because the legs are in a locked position and pumping away like pistons you can't roll the bike.

[hercule]

I think I might have been the first to say something about different muscle groups on this thread. I now feel for having said so....!

Of course I didn't mean different muscles. What I should more accurately have said was different muscle usage patterns, so relative differences in which muscles are being used and different patterns of neuromuscular activation to achieve the result. It's a bit like what happens when you switch from playing say a guitar to a mandolin - you're using the same muscles, but needing to use them differently and in different sequences to achieve the desired result. I have read somewhere that there can be differential activation of muscle fibres in different parts of the muscle belly according to activity, but I may have imagined that...

Whatever is going on, there is a difference between riding DF and riding 'bent and it takes a while to develop the skills to do the one when you are proficient in the other.

[531colin]

Lets just have a slightly-closer look at the quadriceps group.
"Any fule kno" that the quads. straighten the knee.....but look closer.....



Rectus Femoris crosses 2 joints, its attachment points are to the pelvis and the patellar tendon. So contraction of Rect. Fem. can either flex the hip (ie raise the femur) or....it can straighten (extend) the knee. When you are climbing the stairs or riding your bike, you want the contraction of Rect. Fem. to straighten your knee, so your glutes and hamstrings pulling your thigh down must overcome your Rect. Fem. pulling your thigh up.
This is a very common thing in the body, muscles work as agonist/antagonist pairs to give precise control of movement.
Picking another muscle, Vastus Medialis....this one is odd in that it only starts to contract when the knee is almost straight.
so, although I'm sure there are differences between pedalling a DF and a 'bent, they aren't what I would call big differences. You can't make your V. Med. fire before your V. Lat., V.med. only fires when the knee is almost straight, thats hard-wired in, and Rect. Fem. contraction must go with antagonist contraction in order for it to (help) extend the knee.

Asides which I alone find interesting.....
cyclists, distance runners, and others whose chosen exercise doesn't ever get the knee fully straight don't have well-developed V Med. There is a snag.....V. Med is the only muscle which pulls the patella medially, so if you don't have a strong V Med., you can get the patella tracking wrongly, leading to Patello-femoral syndrome, where the patella rubs against the side of the groove in the end of the femur instead of running smoothly down the middle of the groove.
You can demonstrate Rect. Fem. raising the femur by hooking your foot under an armchair and pulling up. Rect. Fem. is the only big muscle concerned with lifting the femur, and it has plenty of antagonists which pull the femur down. But you need to pull the thigh down to run, jump, and climb, you only need power pulling the thigh up in order to kick a football. So there is apparently no evolutionary advantage in playing football.

[[XAP]Bob]

No evolutionary advantage - I can't think of any advantage...

[nigelnightmare]

Re Shorter cranks

They help because you can't rock your hips in a recumbent as you do on a DF, So with longer 175mm cranks your knee is flexing further on a recumbent
Moving it outside the optimum power/comfort range. You end up feeling squashed and overextended with each revolution of the pedals.

Re Up Hill
DF riders are using GRAVITY when they stand up therefore they can keep up the higher output for longer as it's their weight that helps the pedals for almost 120 deg of pedal rotation.
I.E. 2 O'clock to 6 O'clock.
Also they can and do pull up no the handlebars to give even more force which is something that recumbent riders cannot do.

Recumbent riders have to rely solely on leg muscle power without the assistance of gravity/body mass and upper body strength.

Hope that makes sense

[531colin]

Re Shorter cranks

They help because you can't rock your hips in a recumbent as you do on a DF, So with longer 175mm cranks your knee is flexing further on a recumbent
Moving it outside the optimum power/comfort range. You end up feeling squashed and overextended with each revolution of the pedals.

Re Up Hill
DF riders are using GRAVITY when they stand up therefore they can keep up the higher output for longer as it's their weight that helps the pedals for almost 120 deg of pedal rotation.
I.E. 2 O'clock to 6 O'clock.
Also they can and do pull up no the handlebars to give even more force which is something that recumbent riders cannot do.

Recumbent riders have to rely solely on leg muscle power without the assistance of gravity/body mass and upper body strength.

Hope that makes sense

Couple of problems, really......
1) If you are rocking your hips on an upright, then your saddle is too high. Or possibly your cranks are too long and your saddle is too high.
2) The only way you can use gravity to propel yourself is by starting from the top of a hill. When out of the saddle, most people pedal by extending and flexing the knees. However, if you were to pedal by moving your body up and down, then your body moves down under the influence of gravity, but you have to lift it back up again by muscular work, so there is no net gain to be had. (I can't quite picture how that would work....on my bike, when one pedal is at the top, the other one is at the bottom..... )

Certainly on an upright, its possible to use core strength to assist pedalling....but earlier in this thread, I was told that you can generate MORE power on a 'bent by pushing against the seat than you can by working the bars on an upright. If that is the case, then 'bents should climb and accelerate faster than uprights.....which they don't seem to do.

[Dave W]

Considering how long recumbents have been around I'm surprised nobody seems to have worked it out.