The Cadence Conversations

[ratz]

Ok I'm going to open the winter keyboard racing season and encourage people to debate this topic and to keep it civil. Disagree, point, counter point. But be respectful of all points of view.

The V20 encourage a big gear and a slow cadence; you have to actively work to spin. Anyone that's ridden the bike know what I'm talking about.

So how does this apply to training, racing, riding and equipping the bike? I do not know so lets discuss it and see what we can learn. I'll go first.....

Traversing the interwebs the generally immutable facts that do not seem to get argued about (maybe just a little):

• Self Selected Cadence is whatever you train it to be. Whatever you do the most often becomes self selecting. If you don’t train it; then it maps directly to your walking pace
• For a given cadence to be efficient you need to actually train at that cadence regularly. (adaptation)
• The longer the race the slower the cadence you usually pick (specificity)
• If racing and reacting to others in a pack; a higher cadence is advantageous (applicability)
• The greater the forces resisting the movement of the bike (wind and gravity) the more advantage swing to high cadence. Or in other words Low Cadence is more Efficient but it may not be more Economical (situational)

Training Cadence

I have noticed that I have to practice 8-12rpm higher on the trainer than what I want to do on the road with comfort. Example on the trainer I am well adapted to 105-110rpm when I am rested, when I am tired at my worst I am 86-92rpm. When I take that out on the road it on good day I do 92-94rpm and on bad days I’m around 78-84rpm. If I have to and I force myself to I can do 100rpm outdoors but it requires mental focus. I can change that by changing my training.

The short cranks help a-lot with making the spinning practical, having the right amount of leg travel and hip "throw" matters in the lying back position.

Applications to the Road and Racing

You need to test your gears on the road with no wind (or in Zwift on a flat section of road). If you want to ride at 22mph (26 mph for Larry) what cadence do you need to hit in each of your different gears to go that fast; and can you actually do it? and how does it feel? You can model this a gearing calculator but really you still have to try it on the road before your event. You do not want to be in a bunch pack with gearing with big gaps that (at speed the pack rides) forces you to pedal 79rpm and the next gear down forces 92rpm. That going to kill your energy.

Once a race starts you are likely looking at the speedometer, power meter, or nothing at all. Nobody races by staring at the cadence meter, that would be like racing cars by tachometer not speedometer. Cadence in the race will be a result of the speed you need to go and the gearing that allows you to go that fast; if your bike is not geared correctly your cadence will be higher or lower than you want or rather higher or lower than you trained yourself to ride.

Example applications:

On a flat course like Sebring I want a 53/42 on the front of the bike and an 11x23 on the back. That gives me really fine grain control over my cadence at Speed X. The 42x23 to get over that roller on the 11 mile loop when tired and for the climb away from the lake on the crap-tastic rough road. This combination is the gearing that gives me total control to hit the optimal cadence. While different people will want different rings almost everyone benefits from having the 11x23 or 11x25 tight packed cassettes.

On a climbing course with 10% grades, give me a 50/34 and a 12x28; I will sacrifice on the big rings to keep my gapping on the cassette tighter. While a 52/36 and 11x32 might give me more top end for going down hill, my cadence jumps will less granular. Both Gearings are efficient but the 50/34 + 12x28 is more economical. Some races you have no choice and you might have to run 50/34+11x36 or bigger; If that's the case you need to know that ahead of time. You need to go see how much your cadence changes each time you grab 1 gear, and have to maintain the same event specific target speed (assuming negligible wind). Then you need to actually TRAIN for that RANGE of cadences otherwise when you grab a gear you will either find yourself needing a cadence you cannot do; and you'll have to slow down, thus winding up going slower than your strength potential (you could give up 15 watts from a cadence problem).

This quandary is one reason the pros will use: 53/42, 53/39, 50/38, and 50/36 and tend to be exclusively 11x25 on the back for all but the steepest courses. They pick the front for the profile and the 11x25 give them as much cadence control as possible without having to think about it in terms of cadence. The problem is that is an expensive way to outfit a bike for different conditions. It also requires FD re-tuning which is more time consuming. The Cassette meanwhile is much cheaper than the rings and easier to change.

So pick your poison; study the cadence needed and train for what you need for your event; when possible, practical and affordable setup the bike so that you have the greatest odds to ride at the cadence you are most adapted to.

One of the more interesting benefits of Electronic shifting is you can load your FIT files into Di2Stats.com and figure out exactly what gears you actually used during a race. From there you can figure out how to tweak your gearing to give more of what you use most often for a given type of race. It also gives insight on cadences you need to train. If for a given event you used 53x11 1% of the time why was it on the bike for that event? What did you sacrifice for that %1 of the time?

 

[mattwall]

Hi Ratz,
I run a 50/34 with 11x32 on my Silvio 1.5. I need the low gears to get up our hills but do not like the huge cadence jumps.
I am looking at a Schumpf Mountain Drive with a 50 tooth front ring and 11x23 cassette .This would give a larger gear range with small cadence jumps.
There is no overlap of gears between the two ranges. Changing from Hi 23 to the next gear down Low 11 would be a pain as requires changing the Schumpf and simultaneously moving the rear derailed from 23 to 11 . Same going back up.
It would be very nice having small cadence jumps across all gears.

 

[super slim]

Hi Ratz,
I run a 50/34 with 11x32 on my Silvio 1.5. I need the low gears to get up our hills but do not like the huge cadence jumps.
I am looking at a Schlumpf Mountain Drive with a 50 tooth front ring and 11x23 cassette .This would give a larger gear range with small cadence jumps.
There is no overlap of gears between the two ranges. Changing from Hi 23 to the next gear down Low 11 would be a pain as requires changing the Schumpf and simultaneously moving the rear derailed from 23 to 11 . Same going back up.
It would be very nice having small cadence jumps across all gears.

The gear resistance of the Schlumpf Mountain Drive is high and you can feel each tooth engagement when in low drive.
I bought one for a touring trike, and experimented with it on my Silvio V1.0 with a 30/39/53 triple 175 mm crankset, and 11-32 10 spd.
I could only fit the 53 and 39 teeth chainrings.
But with the 2.5:1 reduction, the 39t in low range was the same as 15.6 T, so 15.6 to 17t rear (7th) 24.1" Gear Inches, was the same as 30T to 32 t(1st) 24.6" effective wheel diameter (Gear inches).

I climbed Adelaide's favorite Hill climb, Norton Summit, which is 5.55 km (3.46 mls) long, and 271 m (900 ft) climb, 4.88% average grade.
My best time with the triple 30 to 32 rear was 29:02 mins, 11.4 kph, but 2 days later with the Schlumpf Mountain Drive using Low 9th so same 90 cadence, I was 3 minutes slower, and if using Low / 5th 15.6T(39/2.5) to 21T, 19" Gear Inches, I was also 3 mins slower.

I have since fitted a 24T low chainring to the 74 pcd triple crank, which means I use Low 2nd (21") and 3rd (24") on most of the 5% grade Norton Hill climb, but can change down to first (20") on the steep 180 degree switchbacks!

http://www.bikesmithdesign.com/Short_Cranks/gossamer.html
I would recommend buying a FSA Gossamer Mega Expo 30/39/53 triple crankset with external bearings, and cranks shortened to 153 mm ($239), from Bikesmith Design, an loose the 53T chainring, so your double derailleur and shifter will work.
Ask to get the 30T replaced with a 24T chainring at a slight price increase, should be about $29.
https://www.modernbike.com/interloc-racing-design-defiant-chainring-5x74bcd-24t---silver

This gives you a 27.4" to 52" gear Inches in low range(24T), and 27.4"[12 kph(7.5 mph) @92 cadence], to 42"(7th), [20 kph(12.5 mph) @92 cadence]
And High Range (39T) is 45" to 85" Gear Inches, so 38 kph (24 mph) at 92 cadence.
This gives an effective 17 speeds

If the high speed is not enough, then ask Mark Stonich, of Bikesmith Design, about a 42 T middle chainring so 48" to 92", so 41 kph (25 mph) at 92 cadence, should be about $33
https://www.modernbike.com/fsa-pro-road-s9-c10-42t-middle-130mm-black-chainring
This gives an effective 18 speeds.

If the high speed is not enough, then ask Mark Stonich, about a 44 T middle chainring so 50" to 96", so 43 kph (27 mph) at 92 cadence.
This gives an effective 19 speeds.

You NEED a Middle chainring so there are pins and ramps to speed up the gear change from Low to Middle. I have a Q ring 39T (Low of a double) as the middle, with no pins and ramps on the low side so gear change UP to middle is SLOW! but as I am a tourer and not a racer, it does not matter.

The triple cost of $240+30 =$270 is a LOT cheaper than $850, lighter, and a LOT less friction.

https://hostelshoppe.com/SCHLUMPF-Mountain-Drive-130mm-BCD-79321/
$800 + $50?? to hire the bevel cutter for both of the Bottom bracket outer faces, so the 100 toothed clamps with stop the Mountain drive from rotating.

If you fitted a 50T to the mountain drive and used a 11 to 23 11 speed rear.
The low range would be 23" gear inches to 48" (10kph to 21 kph (13 mph)@ 92 cadence)
The High range would be 57" gear inches to 119" (25 kph (16 mph) to 53 kph (33 mph)@ 92 cadence), so a BIG Gap in the speed range between 13 and 16 mph!


I have a 25/39/53 Q Ring triple with Q Rings from Mark Stonich (As cheaper than I could buy!, AND he fitted them correctly for a recumbent after he requested I sent him side photos of the three Cruzbikes).
I use the 39 T chainring 95% of the time, as fairly flat in Adelaide, cruising at 25 kph(16 mph) using 39 to 17T (7th), so the chain is PERFECTLY straight with a chainline of 44 mm, and only use the 24T and 53T when going up or down hills greater than 4%.

 

[ratz]

I was also 3 mins slower.

Common with the MTN-Drive because it's too easy to gear to low; which is possible and is slower; due to pogoing in the dead-spot.

 

[Eric Winn]

Hmmm, I have a 53/39 and 11x36 but in my most recent flat-ish riding typically spend almost all my time in the 53 and 11x28. Can't remember the last time I've used the 39 ring. Especially after doing lots and lots of miles slogging a 70 pound velomobile around.

I need to try and train seriously and see what happens. Been mostly just having fun and enjoying myself so far. Short stuff I sometimes average up in the low 80 rpm range but I tend to gravitate back toward 70 rpm on the long stuff.

-Eric

 

[McWheels]

I have quite different gearing, a Sturmey Archer 8Sp IGH. However I do get the cadence question. It took me a while to nail down the chainring size I needed, and in truth it could yet be 1 or 2 teeth smaller. 33T chainring, 25T sprocket. the gaps are 15% 2-7, and 30% either end. I have found higher cadence is the way to ride the V2k quicker, so at about 20.5mph (26" wheels) I usually get into 7th on a 80-90% effort morning commute. I think I worked out the cadence on a gear calculator, but have lost the link.

Generally, the harder I try, the higher rpm I need and the later I shift up, it just won't grind out the miles.

 

[ratz]

The gear resistance of the Schlumpf Mountain Drive is high and you can feel each tooth engagement when in low drive.

I missed that of first read. The MD takes about 500-600 miles to break in; then that resistance goes away. Had one on my Catrike and at 700 the resistance was gone. Unfortunately the under gearing still was a challenge. Sure was fun with the 65T ring going down hill though.

 

[super slim]

I missed that of first read. The MD takes about 500-600 miles to break in; then that resistance goes away. Had one on my Catrike and at 700 the resistance was gone. Unfortunately the under gearing still was a challenge. Sure was fun with the 65T ring going down hill though.

When I took the mountain drive off the Silvio, it would have only done 500 miles, so maybe too early, but a Triple is so much easier and the going from 39T to 30T, requires going from 1st to 3rd, OR from 39T to 25T, requires going from 1st to 5th, but with a mountain drive (16T for Mountain, 39 T normal) is required going from 1st to 9th, which takes time, and I fell over a few times as the bike speed dropped too much! ON a Trike that can not happen!

When I went from a 30T low ring to a 25T low ring, I had to learn to change to Low range BEFORE I lost all speed near the bottom of the hill, and change the rear to 5th under light load, then to Low, then change down if required.

 

[super slim]

Hmmm, I have a 53/39 and 11x36 but in my most recent flat-ish riding typically spend almost all my time in the 53 and 11x28. Can't remember the last time I've used the 39 ring. Especially after doing lots and lots of miles slogging a 70 pound velomobile around.

I need to try and train seriously and see what happens. Been mostly just having fun and enjoying myself so far. Short stuff I sometimes average up in the low 80 rpm range but I tend to gravitate back toward 70 rpm on the long stuff.

-Eric

How long do your chains last with all that chain side misalignment and high torque of 70 instead of 90 cadence.

I cruise at 25 kph (16 mph) (SLOW with an Oldish slightly Heavy engine!) on the flat, so at 92 cadence I use the Middle 39T and the 7th 17T rear, so the chain is perfectly inline with a couple of BB shims.

 

[Eric Winn]

How long do your chains last with all that chain side misalignment and high torque of 70 instead of 90 cadence.

I cruise at 25 kph (16 mph) (SLOW with an Oldish slightly Heavy engine!) on the flat, so at 92 cadence I use the Middle 39T and the 7th 17T rear, so the chain is perfectly inline with a couple of BB shims.

I'm generally not mashing at 70-ish rpm, just spinning on the slow end. And most of the time, probably on 53-18 and 53-21 with up and down shifts for all of the short little hills around here. Haven't changed the chain until I was prepping for the MHPVA event back on June 24-25, 2017 weekend and that was only because I bought new chain to switch to waxing. No appreciable wear by eyeball - didn't try and measure wear and everything was working as well as it usually did. Oops, I did change to a new chain after I was side-swiped and dragged by a minivan on July 13, 2013:

IMG_2538 by Eric, on Flickr

I haven't ridden my Vendetta as much over the past three years due to carpal tunnel surgery on both hands (spread out over two years). Right hand surgery was Dec 2014. Left hand surgery was Oct 2015. Wonderful surgery, have not had any carpal tunnel issues since the doc whittled on me. I do have a bit of trigger finger but that seems to be slowly improving.

Currently I have about 4,591 total miles on my Vendetta and around 4,442 miles on my Strada velomobile.

Been riding the velo a lot more. It's a blast, extends my "comfortable" riding season by a huge amount and the tiller steering doesn't use any significant hand, wrist, and arm strength. In fact I've been working on getting fit just riding the velo the past several months: 300 miles in Jul, 500 miles in Aug, 700 miles in Sep, then work interfered and I've only done 274 miles this month so far but I'm also down about 20 pounds.

I'm thinking I'll do the 2018 Bike Sebring with my Vendetta but might do the 12 hour instead of 24 hour to see how my hands hold up - haven't decided yet... The carpal tunnel flared up drammatically on both hands from my 2014 Bike Sebring 24 hour and took about 3 months before my thumb and first two fingers on both hands quit feeling numb - and that was only after getting cortisone injections in my wrists. The shots provided fairly short-lived relief so I decided to do the surgery.

Although I did some KICKR training on the Vendetta over the past winter the first time I had it on the road for 2017 was was on June 23, the day before the HPV weekend and that was only for a few miles to make sure I had the shifting and brakes setup and working correctly. The waxed chain is wonderful. Never going back... Haven't been on it since the HPV stuff back in June but getting ready to start training with the Vendetta on my KICKR for Bike Sebring 2018.

Here is my 1 hour TT on the Vendetta on Jun 24. I have a Stages power meter on it so you can see my actual output. I wasn't pushing at all as I was not in any kind of shape to try and be competitive, um except I took 4th in the overall stock class, helped I'm sure by the prowess of the Vendetta. https://ridewithgps.com/trips/15544122 Average speed 18.4 mph, average 161 watts.

Here is my usual fitness/fun riding route albeit a bit faster than usual on the Vendetta on Jun 7, 2016: https://ridewithgps.com/trips/9354338 Average speed 17.1 mph, average 161 watts, 22.0 miles.

This is more typical: https://ridewithgps.com/trips/9433118 Average speed 16.3 mph, average 150 watts, 22.0 miles.


-Eric

 

[Gary123]

Hate to see an injured vendetta. Also hope you faired ok.

 

[super slim]

Did the rear wheel of the van go over the Vs front wheel?
Was there any fork damage?

How hot is the Velo in the middle of summer?
Is that when the big light gets removed?

 

[Rod Butler]

Cadence;
Instead of using the cadence function, which tells you what you've 'just' done. Try a metronome which gives you a beat to keep up to.
Runners (and some other sports) have been using them for years. Small, light ones are on ebay for a few dollars.
Most have a little red led light, adjustable volume (& jack). Set the beat and take off.

 

[nobrakes]

Cadence;
Instead of using the cadence function, which tells you what you've 'just' done. Try a metronome which gives you a beat to keep up to.
Runners (and some other sports) have been using them for years. Small, light ones are on ebay for a few dollars.
Most have a little red led light, adjustable volume (& jack). Set the beat and take off.

I use a metronome on the indoor trainer. Allows very precise power without having to look at your screen. I find it really useful.

 

[bladderhead]

You were DRAGGED! Sounds bloody terrifying! The wheel is gone, but the frame and forks survived. Do you call that lucky?

 

[tiltmaniac]

I had some trigger finger as well. That was mostly fixed by changing the angle of the handlebars (bullhorns correlated with getting trigger finger).

As for cadence-- a higher cadence implies lower knee torque for any particular energy output.
I've found that the thing that mattered more to me was being sure to pull up on the backstroke. This seems easier to do with a higher cadence.

I have no means to verify, but I wonder if a higher cadence doesn't change the blood-flow. There is some evidence that relaxed muscles mean better blood-flow (https://www.ncbi.nlm.nih.gov/pubmed/1642721). The doctors amongst us would know more, probably.

Anyway, if that is true, then a higher cadence might mean less variance in blood flow to the muscle. If the cells exchange oxygen in a manner that is non-linear with the amount of bloodflow, this doesn't matter. If the bloodflow is more linearly coupled with oxygen exchange (and other chemical exchanges which keep the muscles exciting efficiently), then this matters.

 

[Osiris]

I haven't gotten enough seat time on my Vendetta to be sure, but it does seem that what feels like the most comfortable cadence on it is a good deal less than it is on my other bents (CA2 & M5 CHR). There's a one mile stretch of flat road that I use to gauge my level of fitness, and judging by my Strava uploads, my average cadence on that stretch is right around 80 rpm. That's about 10 rpm below what feels best on my other two bents. I'm not sure why that is. I did swap out the stock 11-28T cassette for an 11-32T cassette, but I don't think that has affected my cadence; the primary benefit of the 32T gear is that it makes it much easier to get the bike going on a hill.

Now as a general question, I've always wondered why some bent riders (not on this forum) champion high cadence pedaling. I'm talking about 100+ rpm. I have tried it, but it always tires me out much sooner while producing no noticeable benefit. It seems counter-intuitive to me to pedal that fast, because the very act of spinning your legs burns energy, even when the resistance is zero. For example, there have been times where I just pedaled as fast as I could on my trainer to see how fast I could rotate the pedals. This was done without the tire touching the trainer's roller, so the resistance was as close to zero as it could possibly be. At a normal cadence of say 80-90 rpm, I could of course keep pedaling all day against zero resistance. But at a very high cadence of 140+ rpm, I couldn't keep it going for even one minute. The very act of pumping my legs that fast left me gasping for breath and exhausted my leg muscles in no time at all. Clearly the effect will lessen as you slow your cadence, but it seems to me that at 100 rpm, you're burning energy at a much higher rate just moving your legs than you would be by pedaling at say, 80 rpm, so why do it?

 

[bazzawill]

I haven't gotten enough seat time on my Vendetta to be sure, but it does seem that what feels like the most comfortable cadence on it is a good deal less than it is on my other bents (CA2 & M5 CHR). There's a one mile stretch of flat road that I use to gauge my level of fitness, and judging by my Strava uploads, my average cadence on that stretch is right around 80 rpm. That's about 10 rpm below what feels best on my other two bents. I'm not sure why that is. I did swap out the stock 11-28T cassette for an 11-32T cassette, but I don't think that has affected my cadence; the primary benefit of the 32T gear is that it makes it much easier to get the bike going on a hill.

Now as a general question, I've always wondered why some bent riders (not on this forum) champion high cadence pedaling. I'm talking about 100+ rpm. I have tried it, but it always tires me out much sooner while producing no noticeable benefit. It seems counter-intuitive to me to pedal that fast, because the very act of spinning your legs burns energy, even when the resistance is zero. For example, there have been times where I just pedaled as fast as I could on my trainer to see how fast I could rotate the pedals. This was done without the tire touching the trainer's roller, so the resistance was as close to zero as it could possibly be. At a normal cadence of say 80-90 rpm, I could of course keep pedaling all day against zero resistance. But at a very high cadence of 140+ rpm, I couldn't keep it going for even one minute. The very act of pumping my legs that fast left me gasping for breath and exhausted my leg muscles in no time at all. Clearly the effect will lessen as you slow your cadence, but it seems to me that at 100 rpm, you're burning energy at a much higher rate just moving your legs than you would be by pedaling at say, 80 rpm, so why do it?

I read a magazine article early in my cycling (DF) career that stated the obvious fact there are two ways a rider can make the bike to faster. Ride harder, in a higher gear, or soon faster.
Riding harder is anaerobic (think weight lifting / mostly building) and their is a limit on how hard you can ride for a sustained period (not many people lift their maximal weight for 4+ hours.
They suggested training to spin faster aerobically would allow you to go faster, longer. However IIRC they only suggested 80-100 RPM. Personally I can only manage 80-90 RPM.

 

[LarryOz]

Now as a general question, I've always wondered why some bent riders (not on this forum) champion high cadence pedaling. I'm talking about 100+ rpm. I have tried it, but it always tires me out much sooner while producing no noticeable benefit. It seems counter-intuitive to me to pedal that fast, because the very act of spinning your legs burns energy, even when the resistance is zero. For example, there have been times where I just pedaled as fast as I could on my trainer to see how fast I could rotate the pedals. This was done without the tire touching the trainer's roller, so the resistance was as close to zero as it could possibly be. At a normal cadence of say 80-90 rpm, I could of course keep pedaling all day against zero resistance. But at a very high cadence of 140+ rpm, I couldn't keep it going for even one minute. The very act of pumping my legs that fast left me gasping for breath and exhausted my leg muscles in no time at all. Clearly the effect will lessen as you slow your cadence, but it seems to me that at 100 rpm, you're burning energy at a much higher rate just moving your legs than you would be by pedaling at say, 80 rpm, so why do it?

There is definitely a balance that must be found between high and low cadence. I tend to think 100 rpm is a pretty good real world limit to shoot for for most people. About that it becomes a cardiovascular detriment, but also training at that level and above can give you a great cardio benefit.
On the other end of the spectrum, as you slow down your cadence you are having to push harder on the pedal, but for less times a minute. At your FTP is becomes increasingly difficult once you drop below 60 rpm, and dropping down to 50 becomes almost impossible. I use cadence drills in the 50-60 range like weight training in the off season.
The point I am trying to get to is this: If you pedal with high load pressure on your legs you cannot last very long. You burn up all the glucose in your legs pretty quickly and it cannot be replaced without rest and diet. You will crash.
There is a huge range between the 2 examples I just presented and I think each person has to find what works best for them at that time. For ultra endurance riding, I suspect that 90% of riders will fall between 75-85rpm.

I may have beat around the bush above trying to say this, but I think there is also great benefit in doing some training at both ends of the spectrum. low rpm for strength and power, high rpm for speed and cardio

 

[super slim]

There is definitely a balance that must be found between high and low cadence. I tend to think 100 rpm is a pretty good real world limit to shoot for for most people. About that it becomes a cardiovascular detriment, but also training at that level and above can give you a great cardio benefit.
On the other end of the spectrum, as you slow down your cadence you are having to push harder on the pedal, but for less times a minute. At your FTP is becomes increasingly difficult once you drop below 60 rpm, and dropping down to 50 becomes almost impossible. I use cadence drills in the 50-60 range like weight training in the off season.
The point I am trying to get to is this: If you pedal with high load pressure on your legs you cannot last very long. You burn up all the glucose in your legs pretty quickly and it cannot be replaced without rest and diet. You will crash.
There is a huge range between the 2 examples I just presented and I think each person has to find what works best for them at that time. For ultra endurance riding, I suspect that 90% of riders will fall between 75-85rpm.

I may have beat around the bush above trying to say this, but I think there is also great benefit in doing some training at both ends of the spectrum. low rpm for strength and power, high rpm for speed and cardio

Do you think that the crank length has an effect on the natural cadence as when I went from 175 mm to 153 mm, my natural cadence, on the flat, went from 80 up to 92, with the same power, AND the same pressure on the pedals.