The Cadence Conversations

[LarryOz]

My lastest workout where I really concentrated on spinning really fast.
https://www.strava.com/activities/1445412617


This was 12 x 6 min intervals that ranged from 88-92 FTP%, so not super high or hard wattages, but a pretty significant time averaging 90% so still a pretty hard workout.
For the entire workout I averaged 107rpm for 2 hours (my highest average yet), the last 20 minute interval I averaged 109rpm, and for the last 6-min interval I average 115rpm.
The nice thing is not to feel the extreme "pressure" and "load" on my legs and knees during the effort. My HR was more elevated and neared 170 at the end, but some of that was because of the rpm, so due to fatigue at 90% FTP for so long.
It was also easier to keep the pace with music going. I was listening to some commentaries for the first 8 of the 6 minute intervals and switched to some of my fast passed worship music during the last 5 and it was easier to keep the higher rpm.
I have been trying to ride at or near 105rpm for the last week or so, and now 100 feels slow, and 90 feels like I am hardly moving.
I believe this is one of the keys to being able to sustain high power levels for 1hr+ TT efforts.
Biggest problem when getting up to the 120rpm range is legs are moving so fast and bike almost bouncing around on the trainer and even trying to scoot across the floor.
I am riding 152mm cranks right now. I may experiment with some 140's or even 130's and see if it is easier to maintain the 120+ rpm since legs will not have to be moving as much.

 

[bazzawill]

My lastest workout where I really concentrated on spinning really fast.
https://www.strava.com/activities/1445412617

View attachment 6483
This was 12 x 6 min intervals that ranged from 88-92 FTP%, so not super high or hard wattages, but a pretty significant time averaging 90% so still a pretty hard workout.
For the entire workout I averaged 107rpm for 2 hours (my highest average yet), the last 20 minute interval I averaged 109rpm, and for the last 6-min interval I average 115rpm.
The nice thing is not to feel the extreme "pressure" and "load" on my legs and knees during the effort. My HR was more elevated and neared 170 at the end, but some of that was because of the rpm, so due to fatigue at 90% FTP for so long.
It was also easier to keep the pace with music going. I was listening to some commentaries for the first 8 of the 6 minute intervals and switched to some of my fast passed worship music during the last 5 and it was easier to keep the higher rpm.
I have been trying to ride at or near 105rpm for the last week or so, and now 100 feels slow, and 90 feels like I am hardly moving.
I believe this is one of the keys to being able to sustain high power levels for 1hr+ TT efforts.
Biggest problem when getting up to the 120rpm range is legs are moving so fast and bike almost bouncing around on the trainer and even trying to scoot across the floor.
I am riding 152mm cranks right now. I may experiment with some 140's or even 130's and see if it is easier to maintain the 120+ rpm since legs will not have to be moving as much.

This is my second ride (return trip) attempting to improve my cadence (unfortunately I only get a chance to ride 2x 20kms at the moment but not a bad start)

and the first

Both of these I was focusing on spinning with not to much load just to train cadence. As higher cadence becomes second nature I will increase power. It will be interesting to see how I go with my minimal training schedule but that is the life of a twin dad.

 

[Brad R]

I made an observation this week. I wanted to ask if others have noticed a similar effect.

Last fall I had a back spasm. The physical therapist taught me an exercise for strengthening the core muscles. It was simply tightening them. It was different than just sucking in the gut because doing it right doesn’t prevent you from being able to breathe. I learned it laying down, but once learned it can be done standing or sitting.

During my 40 mile ride on Sunday afternoon, my back started to feel a little tense and I decided to do my core muscle tightening exercise while riding.

To my great surprise, if riding in a low enough gear to be able to spin reasonably easily, tightening my core muscles increased my cadence and speed by about 5 to 10 percent without any perceived increase in effort in the legs.

Has anyone else noticed a correlation between speed or cadence and relaxing/flexing core muscles?

I tested it again on shorter rides a couple time this week. It happens as long as I can accelerate without to much pressure on my knees.

Any explanations? Flexing core helps the return leg pull to get more work out of each leg? Flexed core lets the legs work against the core muscles and that is more stable and efficient than working through the flesh and seat cushion when the core muscle has s relaxed?

 

[bladderhead]

The latter, I think. Somewhere on this forum a long time ago there was a discussion about sear-pushing and bar-pulling. If you push the seat, your guts acts like a Ventisit and absorbs a load of energy, but if you pull the bars your arms can stay rigid and not recoil or deform or whatever they call it.

 

[DavidCH]

Flexing core

For a long ride I sometimes put pressure on the pedals and lift the small of my back off my seat as though I was going over a bump. I find these elevates tensions enough for me.

 

[Rod Butler]

Over rough ground lately.
I've pushed my shoulders back into the upper seat by extending my hands, hard into the handlebars
and doing an ab crunch to lift my butt off the seat.
Works for me but took a little practice.

 

[ElyDave]

50km on the S40 today, I was feeling that my cadence was a bit slow, as the Garmin screens rolled around it showed me 90rpm.

Happy enough with that, 95-105 now seems to be getting seriously ingrained

 

[DavidCH]

I get to 110 rpm and I'm doing 42kph and start to have twinges of fear. Basically my boom is just a little too far out. If you feel that way don't push it but adjust it.

The objective is to be happy doing 120 rpm

 

[LarryOz]

The objective is to be happy doing 120 rpm

Yeah - Once you can do 120 all day long, 100 feels like you are barely moving!
btw - I am not there yet! haha - trying to keep it between 105-110 during training workouts. In reality it is really hard to keep it above 100 out in the real world for some reason.

 

[RAR]

In reality it is really hard to keep it above 100 out in the real world for some

I think that's called wind resistance.

 

[Balor]

In reality it is really hard to keep it above 100 out in the real world for some reason.

I think it has to do with managing pedal steer torque in real world. It gets really hard to get in perfect sync without uniform hard pull on the bars, and latter is quite tiring because uniform contraction (isometric) severely impedes blood flow - it is even recommended as a fast way to train slow twitch muscles that are otherwise very resistant to fatigue and require super-long (think century ride) efforts to properly work out.

Anyway, I've always been more of a masher, but after installing short cranks I do find spinning much easier which is logical - your muscle contraction speed remains unchanged at higher cadence with shorter cranks. Too fast muscle contraction speeds, based on what I've read, generate too much 'fiber-fiber' internal friction which is partly viscous and hence quadratic... I case you don't know, muscle fibers can only contract or not contract, we can only vary the force by varying number of contracting fibers, and we NEVER use all of them at once - that might actually tear the ligaments off. Friction between fibers that contract and those that do not account for most of the losses after biochemical conversions.

I've also been working to improve my highest cadence at sprints. Finally got around to installing cadence meter.
At 140mm crank length I can hit 160, and it seems that my max power is not much changed by fitting shorter cranks.
https://www.strava.com/activities/1876282602/

I still find cadences above 90 mentally exhausting. I guess I need to train more.

 

[Osiris]

Anyway, I've always been more of a masher, but after installing short cranks I do find spinning much easier which is logical - your muscle contraction speed remains unchanged at higher cadence with shorter cranks. Too fast muscle contraction speeds, based on what I've read, generate too much 'fiber-fiber' internal friction which is partly viscous and hence quadratic... I case you don't know, muscle fibers can only contract or not contract, we can only vary the force by varying number of contracting fibers, and we NEVER use all of them at once - that might actually tear the ligaments off. Friction between fibers that contract and those that do not account for most of the losses after biochemical conversions.

Does that suggest that a low rpm/high torque style of pedaling may be more efficient because a higher percentage of muscle fibers are contracting? I seem to recall reading a study which said that a pedaling cadence of somewhere in the mid 70's rpm proved to be the most efficient for power production, but that no one would want to pedal hard at such a low cadence due to knee strain.

I've also been working to improve my highest cadence at sprints. Finally got around to installing cadence meter.
At 140mm crank length I can hit 160, and it seems that my max power is not much changed by fitting shorter cranks.
https://www.strava.com/activities/1876282602/

I still find cadences above 90 mentally exhausting. I guess I need to train more.

On a bent (it doesn't seem to matter which bent), I feel most comfortable pedaling at around 80 rpm, whereas on my DF it's about 15 rpm higher. I've yet to figure out why I can't pedal nearly as fast on a bent. Even on a trainer, it's hard just to reach 125 rpm, whereas on my DF, I managed to hit 167 rpm in a sprint. The DF has 172 mm cranks, compared to the 165 mm cranks on most of my bents.

 

[Balor]

Does that suggest that a low rpm/high torque style of pedaling may be more efficient because a higher percentage of muscle fibers are contracting? I seem to recall reading a study which said that a pedaling cadence of somewhere in the mid 70's rpm proved to be the most efficient for power production, but that no one would want to pedal hard at such a low cadence due to knee strain.

That's more complex - in physiology, there is optimum muscle contraction speed to muscle load, both too fast and too slow costs efficiency. Plus, different types of muscle fibers have different contraction speed at which they are most efficient. Admittedly, that's the extent of my knowledge - I've tried getting into molecular biochemistry and physics of muscle fibers and got stumped, it assumes a lot of specialized knowledge that would take a lot of time to accumulate, so it is not just about 'knee strain'. Cadence drills can be pretty hard on knees as well, I can tell you that.

My higher BB bent is being remade, it wonder how higher BB (I presume you don't have low BB bents yourself) affects your cadence. I still think that my max cadence is higher on DF, and quite a bit more power as well.
It cannot be 'openness' of position - my position is more open than most production bents even reclined to the max, yet as you see I can hit decent cadence numbers.

Gotta try 'field testing' and see how management of pedal feedback will affect it.

 

[Balor]

Well... went for an outdoor ride and result are... both unsurprising and surprising at the same time:

https://www.strava.com/activities/1877615455

My median cadence turned out to be 98... well, I daresay not surprizing given 140mm cranks, but why the hell my median cadence on a trainer is 87? This is turbo muin, it has rather large freewheel and fluid resistance curve... very steep btw, it may have something to do with it I presume. A very small change in cadence or gearing results in huge spikes in power required.

 

[Osiris]

My higher BB bent is being remade, it wonder how higher BB (I presume you don't have low BB bents yourself) affects your cadence. I still think that my max cadence is higher on DF, and quite a bit more power as well. It cannot be 'openness' of position - my position is more open than most production bents even reclined to the max, yet as you see I can hit decent cadence numbers.

I'm not sure how BB height might account for it, but there's definitely a difference when pedaling a bent compared to any of my DF's. It's not just that I can pedal comfortably much faster on a DF, it's also that the strain on the upper ends of my thigh muscles seems much worse after a long ride on my bents than on a DF.

 

[Balor]

it's also that the strain on the upper ends of my thigh muscles seems much worse after a long ride on my bents than on a DF.

That's a very common complaint, and something I do not have - at least in the 'upper' thigh. My hamstrings always hurt, though. It would be interesting to see my 'power figure of eight' shape on a bent... that would require investment into something like Garmin Pedals though.

I'm very interested how IQ2 PM will turn out, if it meets expectations I'll sure to grab a pair, seems affordable, and increase in Q-factor might be a blessing in disguise - I have wide hips and already find MTB crankarms more comfortable. Using road cranks with those adapters might actually be more comfortable for me.

 

[Balor]

Anyway, since our body essentially being a tensegrity structure, it kind of makes sense how changing bracing points can have widely varying implications across entire body, and in a very complex and non-intuitive ways...

 

[Osiris]

That's a very common complaint, and something I do not have - at least in the 'upper' thigh. My hamstrings always hurt, though.

The pain in your hamstrings might be because you use the "scraping" pedaling technique on a bent, but not on a road bike. Scraping strongly engages the hamstrings, which I can feel every time I ride my bent. On the DF however, I seem to employ the quadriceps to a much greater degree, so my hamstrings never feel tired after a long ride on a DF. I need to try the scraping technique the next time I ride a DF and see if it works as well as it does on my bents.

 

[Balor]

The pain in your hamstrings might be because you use the "scraping" pedaling technique on a bent, but not on a road bike. Scraping strongly engages the hamstrings, which I can feel every time I ride my bent. On the DF however, I seem to employ the quadriceps to a much greater degree, so my hamstrings never feel tired after a long ride on a DF. I need to try the scraping technique the next time I ride a DF and see if it works as well as it does on my bents.

Well, that's a certainty. I've trained my hamstrings to a point I think they give me considerable edge on df in seated sprints where there is a very strong 'scraping' component' for proper execution. I think can sprint as hard or maybe even faster than I've used to, and pretty much nearly as fast as on a bent - none of *my* bents have very good aerodynamics though. And the stronger my hamstrings get, the more power I get on a bent.

I'm still reasonably slower than I've used to though in normal riding on DF, where contribution from hamstrings is indeed minimal and just does not feel like an effective way of generating long-term power. I presume it is simply much less mechanically efficient - if I used DF much more (I've used to have about 6k miles a year on DF, now it is about 1k DF and 5k bent) I'll likely get back my 'pushing' power AND retain better seated sprint ability, but I loath using DF bike for training, not just 'commuting' to our parents summer cottage (just 10 miles away).

Using shoulder boosters (plus much stiffer seat) would be an ultimate test of my 'bracing theory', which predicts that I should be able to generate much more power that way and use my quads once again, especially combined with Rotor Cranks - which I'll have to get rewelded (they are CNCed in the middle) and shortened.

 

[paco1961]

That's a very common complaint, and something I do not have - at least in the 'upper' thigh. My hamstrings always hurt, though. It would be interesting to see my 'power figure of eight' shape on a bent... that would require investment into something like Garmin Pedals though.

I'm very interested how IQ2 PM will turn out, if it meets expectations I'll sure to grab a pair, seems affordable, and increase in Q-factor might be a blessing in disguise - I have wide hips and already find MTB crankarms more comfortable. Using road cranks with those adapters might actually be more comfortable for me.

About 2 or so months into making the DF to CB transition I was having some IT band problems so I ordered a set of 1cm pedal spindle extenders. Besides immediately helping the IT issue I was delighted with an immediate improvement in balance. No idea on power output but it certainly can’t hurt.

My ave cadence is also about 10-15 rpm lower on a CB. Working on spinning but while I’m sure I’ll improve I don’t see any way I’ll match my typical DF cadence. Mostly an issue of stability at high cadence