The theory of marginal gains states that if you take any system and improve every individual aspect by just 1 percent, you can dramatically improve overall performance by stacking the small gains into one significant improvement. This approach has proved successful in arenas ranging from business to professional cycling — and, yes, even ultralight manual wheelchairs.
The very definition of an ultralight wheelchair has dramatically changed over the past four decades. In the 1970s, an aluminum manual wheelchair approached 40 pounds, but decade by decade, weights dropped. By the late 1990s, an ultralight manual wheelchair was formally defined by insurance coding as weighing 29 pounds or less in its base configuration. However, due to never-ending marginal gains in ultralight chairs on the part of manufacturers consistently pursuing lighter weights, most now see 29 pounds as heavy in a world of sub-20-pound ultralight models.
So, what makes the latest designs in ultralight models and components so astoundingly ultralight?
What’s in a Pound?
The iconic Quickie brand has never stopped pushing the envelope when it comes to reducing weight, especially in the widely-funded K0005 class of ultralights. The newer Quickie 7RS is among its lightest models to date, weighing in at 17.67 pounds complete for a 16-by-16-inch seat size, with a transport weight of 9.88 pounds. So, how does the Quickie 7RS achieve such an impressive weight?
It begins with using 7000 series aluminum for the frame, which has a higher strength-to-weight ratio than a comparable 6000 series aluminum, allowing a very strong, light structure. From there, the Quickie 7RS squeezes out every ounce by using a minimally adjustable axle mount instead of a highly-adjustable one, and an integrated welded backrest that eliminates mounting brackets. These two areas alone not only shave just over a pound off the chair, they also increase propulsion efficiency by more directly translating the user’s energy into each push rather than being absorbed by bulky frame components. To reduce weight even more, Quickie offers an ultralight seat sling, not overlooking even the smallest weight-saving detail.
In a market where ultralight has become somewhat synonymous with ultra-expensive, the Quickie 7RS is a high-performance rigid ultralight that fits many conventional funding sources.
’Lite Keeps Getting Lighter
The TiLite TR is a bit like an iPhone — when someone says they have one, you have to ask, which version? Indeed, the TiLite TR — now on its third series — has been an industry leader in high-end ultralights for years. However, even the newest version continues receiving weight-reducing refinements, bringing today’s TR in at 16.9 pounds in a 16-by-16-inch seat size, with a transport weight of 9.3 pounds. That’s astoundingly light for also being among the toughest, strongest rigids on the market.
The TiLite TR’s ultralight weight is mostly due to its titanium frame. Its strength-to-weight ratio is higher than aluminum, so you can decrease the weight of the frame itself without compromising strength. However, that doesn’t tell the real story as to why the TR is so light.
If you look at the current TR, you’ll note that it’s not a mono-tube frame, but a unique swept-in box frame, meaning there are both top and lower tubes, seemingly doubling the frame material. So, how does this create a lighter chair?
In order to create strength and durability in a mono-tube frame (with one frame tube per side) thicker-walled tubing is required, which adds weight. By going to its dual-tube design, the TiLite TR actually reduces weight by creating a super-strong reinforced structure using extremely light, thinner-walled tubing. It sounds counterintuitive, but more tubing equals less weight based on how it’s applied.
TiLite hasn’t just focused on making an ever-lighter frame. Its newer “bullet caster housing” removes even more weight in this typically bulky area. To drop weight even further, TiLite offers an optional carbon fiber camber tube along with an all-titanium backrest and footplate for an unbelievably ultralight package.
The TiLite TR Series 3 isn’t the most funding-friendly ultralight. However, if you have exceptional insurance or are paying out of pocket, the weight savings warrants the steeper price tag.
Frog Legs Makes Another Leap
Frog Legs suspension forks have been the premier ultralight accessory for two decades. Although they’ve evolved and slimmed over the years, they’ve still always added bulk and weight over conventional caster forks — that is, until now. The new Frog Legs Phase-Two fork (double or single-sided) is made out of carbon fiber and is said to have twice the tensile strength of the aluminum version, with less weight.
Additionally, although not yet for sale at press time, Frog Legs is introducing a corresponding carbon fiber caster that’s 33 percent lighter than its aluminum counterpart. In all, Frog Legs Phase-Two forks are a big leap in allowing the benefits of caster suspension in a compact, ultralight design.
Lightening the Load
Reducing the weight of an ultralight manual wheelchair isn’t just about numbers. It’s about practical impacts on our everyday lives. A lighter chair is simply easier to propel and transport. Saving a pound here and there on an ultralight may not sound like much. However, the marginal gains add up when correlated with quality of life via less body strain. That may be the greatest benefit of marginal gains, after all.