Does pulling up help?

Changes of Pedaling Technique and Muscle Coordination during an Exhaustive Exercise

SYLVAIN DOREL1 , JEAN-MARC DROUET2 , ANTOINE COUTURIER1 , YVAN CHAMPOUX,2 and FRANÇOIS HUG1,3 1 Research Mission, Laboratory of Biomechanics and Physiology, National Institute for Sports (INSEP), Paris, FRANCE; 2 Ve´lUS Group, Department of Mechanical Engineering, University of Sherbrooke, Sherbrooke, Que´bec, CANADA; and 3 Laboratory

“From a practical point of view, the mechanical adaptations observed in our study (i.e., higher downstroke effective force and lower mechanical effectiveness and effective force around the top dead center at the end of the effort) question the pertinence to perform a specific training program to improve mechanical patterns and more specifically, the ability to pull up the pedal more efficiently.”

Effects of Pedal Type and Pull-Up Action during Cycling

really interesting read

Interesting PDF

No difference in effeciency



mechanical efficiency hasn’t changed much in bicycles since the beginning.

Asher Straw reviews the literature for effeciency of clipless pedals:

Cycling enthusiasts and manufacturers have long claimed that rigid-soled cycling shoes and clipless pedals are “more efficient” because they allow riders to pull up during the pedal stroke. However, numerous researchers have shown this to be incorrect. Most notably, Korff et al. (2007) recorded a significant 5.9% decrease in gross efficiency when they instructed subjects to focus on pulling up during the pedal stroke as compared to “pedaling in circles”. Further, Ostler et al. (2008) compared the efficiency of cycling with tennis shoes on both flat pedals vs. classic toe clips and straps at different power outputs (60-240 watts) at a cadence of 90RPM. They concluded there was no difference efficiency between the two types of pedals. Mornieux et al., (2008)compared athletic shoes on flat pedals to cycling specific shoes and clipless pedals in competitive cyclists. They too found no significant differences in the rates of oxygen consumption. Recently, we (Straw & Kram, 2016), reported that cycling efficiency did not differ when riders wore flexible running shoes with flat pedals vs. rigid-soled cycling shoes with clipless pedals. Thus, the evidence to date is unequivocal that shoes and pedals do not improve efficiency.

Optimal cadance

What’s your optimal cadance? The going wisdom from trainers seems to be ‘higher is better’ with CTS reccomending 100rpm. But the literature in the journals suggest that may not be the only optimal scenario.

Some geeky articles below on cadence:

Determining optimal cadence for an individual road cyclist from field data – proposes taking 6 month of power, cadence and Heart rate data into account to determine optimal pedal cadence.

Effects Of Cadence on Aerobic Capacity Following a Prolonged, Varied Intensity Cycling Trial

Javier, Chavarren & Calbet, Jose. (1999). Cycling efficiency and pedaling frequency in road cyclists. European journal of applied physiology and occupational physiology. 80. 555-63.10.1007/s004210050634.


. 2011 Dec; 111(12): 2885–2893.
Ergonomics, Volume 20, 1977 – Issue 5

Published Online: 25 Apr 2007

. 2011 Dec; 111(12): 2885–2893.
Published online 2011 Mar 25. doi:  10.1007/s00421-011-1914-3
PMCID: PMC3218268
PMID: 21437606

The relationship between cadence, pedalling technique and gross efficiency in cycling

“In conclusion, energy expenditure is strongly coupled to cadence, but force effectiveness, as a measure for pedalling technique, is not likely the cause of this relationship. Along with other studies (Kautz and Hull ; Ettema et al. ; Lorås et al. ), we are inclined to conclude that FE is mostly affected by inertial forces, and thus the value of this parameter as a measure for technique should be questioned. “


Cycling efficiency and pedaling frequency in road cyclists –

Key Points from above

  • “When competitive cyclists perform prolonged exercise that simulates racing conditions (i.e., variable, low-moderate submaximal cycling), a higher cadence results in excess energy expenditure and lower gross efficiency compared to a lower cadence at the same power output.
  • Consequently, maximal power output is reduced during a subsequent exercise bout to exhaustion after using a higher cadence.
  • Selection of a lower, more energetically optimal cadence during prolonged cycling exercise may allow competitive cyclists to enhance maximal performance later in a race.”


pop article that says:”shoot for 80″


the vaic takeaway is that work done in cycling can be best measured as Gross Effeciency:

We focus on the effect of cadence and work rate on energy expenditure and efficiency in cycling, and present arguments to support the contention that gross efficiency can be considered to be the most relevant expression of efficiency. A linear relationship between work rate and energy expenditure appears to be a rather consistent outcome among the various studies considered in this review, irrespective of subject performance level. This relationship is an example of the Fenn effect, described more than 80 years ago for muscle contraction. About 91% of all variance in energy expenditure can be explained by work rate, with only about 10% being explained by cadence. Gross efficiency is strongly dependent on work rate, mainly because of the diminishing effect of the (zero work-rate) base-line energy expenditure with increasing work rate. The finding that elite athletes have a higher gross efficiency than lower-level performers may largely be explained by this phenomenon. However, no firm conclusions can be drawn about the energetically optimal cadence for cycling because of the multiple factors associated with cadence that affect energy expenditure.
Efficiency in cycling: A review (PDF Download Available). Available from: [accessed May 28 2018].

pedal measurementrs

clipless only

another one

Pedal across Washington

Welp – this year’s adventure seems all but chosen: . This route crosses washington west to east, La Push to the Idaho border. A fit rider should make it in 7 days (+/- 3 in my case). The planner says it’s a quarter of the divide – 25% as long, 25% as tall (at the height of the elevation).


May 20 til it’s done.

Now all I have to do it get fit.

Electronics on the Tour Divide: Dynos, Chargers, Cables Oh My!

On my Tour divide trip last year, keeping my electronics charged was a huge pain. Some lessons learned below.

Charging Cables are a Single point of Failure

TL;DR – Cables fall apart *really* fast. Bring spares! Get electronics you can swap batteries on, especially batteries you can buy at a gas station.

For most folks, the electronics you bring on the tour divide are critical: you need them to see at night (lights), follow the course (GPS), or get help if you’re stuck (phone/SPOT). We all take care to make sure we get rugged devices, but it’s easy to overlook one of the most basic failure modes – dead battery.

I went into last year’s race feeling pretty self assured because I was rolling a SP PD-8 dynamo hub. I knew I’d have electricity to spare. As a backup, I brought a big battery bank. What I overlooked was that no matter how many electrons I had to push into my devices, none of that mattered if the cables wouldn’t connect. Oops.

For example: I was using my cellphones for navigation. This worked *great*, as long as I had enough battery power. I used a Sinewave Reactor to get USB power out of my dynamo hub, but no matter how long I had my phone hooked up to it, it never charged up because the damn cable wasn’t actually connecting to the contacts in the phone itself. Imagine riding along in the wilderness watching your power level drop and trying to fiddle w/ the cable to get it to charge while going fast enough to keep current running from the dynamo. In a word: impossible.

I’ve never had these problems on other routes – my dyamo setup worked great on the Oregon outback. I think it basically happens because of: the intense vibrations + long duration. My guess is that the internal contacts on the cables themselves just fall apart after a couple days.

Cables are a Single Point Of Failure. Once they start to fail, even being connected to a wall based power supply doesn’t help (much). I spent literally hours jury rigging my cables and phone so that they’d charge overnight. Put a snickers bar under the cable, and a shoe on top of my phone, then check after 5 minutes to see if the little lightning bolt was still there and pray to god it lasted all night.

So – some lessons learned:

  • Get quality USB cables. It sounds rediculous, but you get what you pay for in cables. Since I got back, I’ve been using Anker USB cables for charging. These seem *way* more durable. There are also other ruggedized cables out there. I brought one of these too, and ended up throwing it away, so on to point 2…
  • Bring extra cables. Even with ruggedized cables, I found I could rely on a cable for 3-5 days. Cables are cheap. Buy good ones, bring a lot. If you’re worried about weight & bulk, bring short ones. Don’t count on buying these on the road. You’ll get crappy ones for a lot of money (I spent $25 on a cable in Whitefish, MT). Better to carry more from the get go.
  • Have a backup charging plan. Does your device have removable batteries? Bring a spare. Can you charge your spares w/o a USB cable? Bring that too!
  • Bring devices you can buy batteries for. You know what’s faster than recharging your USB flashlight from the wall? Putting in new AAA’s.
  • Take care of the batteries you bring. Cold temperatures mean bad performance for batteries – keep them warm at night; Don’t drop them.
  • Bring fast chargers, and fast charging devices. If it takes you 8 hours to charge your batter cache, guess how long you’re stuck at a wall socket? Many chargers and devices have fast charging modes now – you could be on your way in half the time.
  • Get a ‘pass through‘ battery cache. If you can charge your device & your cache at the same time you’ve just increased the amount of time you can go before your next stop. Not many battery caches have this feature, do your research and _test_.
  • Figure out your ‘dead device’ plan. If your gps dies, how will you navigate? If your spot dies, how will  you stay in the race? What do you do if your lights runout in the middle of the night? A small Backup light, a rudimentary paper map, and spare Lithium batteries are your friends.

Given how quickly my cables failed, I must say I’m *really* impressed with how durable my SP Dynamo, Sinewave Reactor and K-lite are. The K-lite cables and interconnects are exactly what I’d *like* to be charging my phone with. Maybe Kerry’s got something up his sleeve for the future for phones…

In the mean time, I’m going to start playing around with ways of charging my phone without using USB cables. Wireless chargers have notoriously low efficiency, but poor effeciency + highly reliable is better than a highly efficient cable that doesn’t work.

Electronics were a huge source of comfort and courage for me on the tour – knowing that people were following my ride helped me keep going. Being able to ride into the night let me go farther. Having mine be so tenuous during 2016 was really aggravating. I remember almost running out of cell phone power when calling my family on Fathers day. Next time I go I hope to do better on this front.

Charging on the trail: Dynamo, Solar or Battery Cache?

First things first: Have a backup. Going Battery Cache only? Bring 2 (hell, bring 3!). Bringing a dyno? Don’t skip a cache.

Should I go battery cache only? It’s not a crazy idea. The trick is that  you will likely need more power than you estimate: cache’s perform worse in the cold; your devices will need more power than you think (searching for cell towers or wifi). The solution here is to bring more, and the cost is weight. You should also consider how to keep your caches from failing physically: what happens if they get wet? Will it break if it gets dropped?

What about Solar? Solar is appealing because there are no moving parts. But… weather. And weight. Can you really haul enough panels to power what you need? How will you keep them oriented to the sun? It’s an interesting idea, but seems risky.

Why Dynamo? I love my dynamo lights – every time I move, I get power. But.. they do introduce (very minor) resistance, and they are mechanical and do fail. When they fail, they are really hard to repair. So… it’s also risky. If I had unlimited money, I’d bring this one as a backup.

End of the day, Dynamo seems the least risky and most flexible of all to me, and I have no plans to switch.


Keeping Guylines untangeled

In the spirit of keeping time off the bike down, here’s a trick to making tent (or hammock) setup fast:

  1. Make small pockets for your lines at tie out points. I plan on using Cuben tape for mine.
  2. Wrap your lines in a figure 8 when packing

Here’s a good guide on how to do this. Super handy!


Sleeping, Apnea and the Tour Divide

Racing the Tour Divide is all about sleep. Wanna go faster? Ride more, sleep less. To cover 190 miles a day, the winners ride 18 hours. If you’re lucky, 3 0f the remaining 6 hours are for sleep. Now imagine that with sleep apnea, a condition which keeps  you from breathing correctly while asleep.

You wouldn’t recovering enough to put in any sort of athletic performance, and you’d have a very hard time making memories. Worst case scenario: microsleeping while on the bike – it’d be easy to ride right off the road into who knows what.

My own apnea is serious enough to drop my blood oxygen level down below 80% when sleeping at sea level. Sleeping at 5000 feet makes it worse.

What’s adventuresome soul to do? Mandibular Advancement Devices seem like a good choice for some folks, but if your apnea is more that moderate you’ll likely need to haul around a CPAP. As far as I know, nobody makes an extension cord long enough for the Tour Divide.

HDM Z1 CPAPEnter the HDM Z1 Auto. It’s a small, light weight cpap built for travel. Thanks to the generosity of HDM, I was able to carry one this year.

The Z1 itself weighs about 10 oz – about the same as a light weight sleeping matt. The base, batteries and charger bring the total weight up to a bit more than 2lbs. Less than your tent. Less than a synthetic sleeping bag. And in terms of your ability to recover from a strenuous day, just as important.

The Z1 + the powershell is much less bulky than my home CPAP unit, and fit nicely stuffed int20160627_191707o the bottom of my Revelate Designs Viscacha, or my Jones fork micro panniers.

Sleeping in the woods? The Z1 is battery powered. The lithium ion battery will last a full 8 hours when fully charged (watch out for cold weather though, might be worth moving the battery inside your bag if it’s very cold outside).

IMG_20160612_140725609_HDRCharging takes 5+ hours, and doesn’t take place while using the Z1 itself, so if you need to stay outside 2 nights in a row bring a spare. Maybe future versions of this device will be able to charge the battery while the unit is in use. Until then, you might consider bringing 2 chargers (1 for the battery, one for the cpap) to charge up while you’re sleeping if electricity is available.


The Z1 is a bit noisier than my home unit, but this is a small price to pay for good sleep in the woods. I like to think that the sound from the unit scared off Bear 6 (the worst bear – the one I never actually saw) at the Red Meadow pass, where I was sleeping alone at 5,5000 feet. It also has a few small custom pieces that are important not to lose. Best to keep the custom hose adapter attached to the hose at all times, or perhaps bring a spare.

Particulars aside, the Z1 really lets me expand the range of adventures I can undertake. smilesGetting good sleep lets me ride harder and stay happier than waking up night after night with a hangover from an oxygen diet. What’s most important though is that I was able to stay positive and focused on this incredibly demanding trip. A bad nights sleep for me is a recipe for pessimism, procrastination and a painful head – no way to keep on keeping on in the worlds longest mountain bike race. The Tour Divide is certainly one of the greatest adventures of my life, I’m happy to have had the Z1 along for the ride.