If an Alchemist was a Climber: Spreng Reng Continues Refinement of the Omni-Radius Chainring

The Spreng Reng is designed so that one side of the chain-ring within the entire power stroke segment is a smaller radius than the other side, thereby increasing the mechanical advantage of that crank arm.

Climbing hills is a fundamental component of the bicyclist experience. For instance, the #bicyclistchallenge route profiled in Issue 151 sees 7,600’ feet of climbing over 62 miles, a significant challenge for even the veteran road-cyclist. For some, this is a welcomed challenge, but for others, it can be an insurmountable barrier to experiencing all the sport has to offer.

The physical and mental exhaustion experienced during a climbing segment can make sustained and incremental training difficult. And for some inexperienced riders, their base level of fitness precludes even considering adventuring on road or trail with significant elevation changes. The allure of electric bikes can be explained by this; removing the physical and mental challenge of cycling, and allowing individuals to skip ahead to experiencing the world at 18mph – the perfect speed for experiencing the natural, architectural and social grandeur all around us – ‘Earn those turns’ be damned. And that’s a good thing!

illustration of a road cyclist climbing up a mountain

More people on bikes – electric or otherwise – increases the constituency of cyclists. But for the individual, they are denying themselves the mental and physical development that comes from incremental hill climbing. There is a moment that all aspiring bicyclists have had – the hill that ‘almost’ won, but you prevailed. Having that singular experience will informs future climbs, reminding you that no matter the grade, you will prevail, just as you’ve done many times before. It may take you time and toil, but you will have earned the ultimate confidence in yourself, the mental strength to continue and determination not give up when every primal sense is screaming at you to quit.

animated

So what are the options for the beginning hill-climber who refuses to skip ahead to the reward of peak vistas, and rapid descents via electronic assist? To “climb often, take it slow and SPIN – always be spinning,” is the refrain from across the cycling zeitgeist. Though good advice, it can be problematic for the newcomer who has run out of gears and is still not ‘spinning’. A triple chainring up front is an option, but will be quickly outgrown once regular training and dedication to the hills has commenced. The limited availability of such triple options is explained by this fact. A more generous rear cassette can provide some relief, but with sizing limits of road derailleurs, that may not be enough.

There is a moment that all aspiring bicyclists have had – the hill that ‘almost’ won, but you prevailed. Having that singular experience will inform future climbs, reminding you that no matter the grade, you will prevail, just as you’ve done many times before

Mechanical Relief

An option that came across our desk to help address this barrier is a non-round chainring that is being developed by Douglas Brown, Jr. and released under the Spreng Reng moniker as a replacement for 110 BCD chainrings, either inner double or as a 1x replacement, both for road. The Spreng Reng is designed so that one side of the chain-ring within the entire power stroke segment is a smaller radius than the other side, thereby increasing the mechanical advantage of that crank arm. The radius of the ring changes as it rotates, either favoring your left or right leg depending on how it is installed. The chain-ring can then be adjusted to equalize the power between legs and provide a faster cadence, and ultimately faster speed. Or it can be used to provide easier gearing to the dominant limb and more challenging gearing for the weaker limb.

While riding, the Spring Reng replaces a 38t gear and instead provides 37t gearing for one limb (easier), and 39t gearing for the other (harder). Since riders will have unbalanced power between the left and right limbs, tuning the power stroke to amplify, or equalize this unbalance between limbs can lead to faster cadence, while power output is maintained – the key recipe for increasing your speed. Spin faster, remember?

For individuals with muscular or balance constraints, the Spreng Reng could be the difference between being able to spin over the local club grade, or having to mash the pedals as if whipping molasses with a canoe oar. It also provides an emergency option for climb-heavy events, where having that extra mechanical advantage is the difference between suffering the climb and finishing, or quitting the climb and getting Uber’d home.

The Spreng Reng is not yet available to the public. The version we received was Version 20, and continues to see refinements. It’s an unconventional design, but one we will see more of in the future as riders continue to look to industry for performance advantages and tuning options to address the assortment of issues that effect a subset of the cycling populous.

As we look forward to seeing continued development on the Spreng Reng, and acknowledge the place it has, especially in the coaches tool kit, the biggest hurdle to climbing is mental. It’s a hard truth to accept, but the pain stays the same. Training helps you pedal faster and become more accustomed to the discomfort, until ultimately, the discomfort becomes something you’ll seek out. And when that day comes, the #bicyclistchallenge will be waiting for you.

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like
Read More

The 1989 Iron War Revisited

The Kona Ironman world championship consists of a 2.4-mile swim in a calm bay in downtown Kona; a 112-mile bike race through the barren black fields, climbing up the lush mountain road with green grass to the small town of Hawaii; then back down, through the lava fields to the Kona Surf Hotel outside of Kona
Read More
Read More

Antiperspirant: Bad to Worse?

Despite the popularity of antiperspirant deodorants today, most Americans didn’t use them until the early twentieth century. For the average person, the antidote to unpleasant smells was often heavy amounts of perfume and altered clothing, such as cotton sweat pads under the armpits.
Read More
Read More

The e-Chariot

My friend Ron’s granddaughter is a precocious nine years old with a penchant for mechanical things. She conceived the e-Chariot to be a vehicle that would allow her family, including her 12-year-old physically challenged sister Hailey, to bicycle together.
Read More
Read More

The One Way Ride to Mexico

The One Way Ride Program officially began in 2012, but these men have been carrying on this tradition for over a decade. It all started after the 2001 Rosarito to Ensenada ride when local resident Raymond “Randy” Kiefer and his riding partner, Hank Williamson, generously gave away their bicycles to two local teenage boys who were hanging around the finish line watching the riders come in.
Read More
Read More

India by Bicycle: A Brief Survey

When I lived in India for six months in 2014 doing environmental research, I always traveled to my host institution in the northern Bangalore suburbs on my bicycle. It was 6 km away and only took me about 20 minutes. It was a lovely trip through a colorful neighborhood and I relished the sights, smells, and sounds. But, the rides were challenging, both physically and emotionally.
Read More