Monotubing Me

The saying that everything old becomes new again has never been truer than when it comes to today’s ultralight manual wheelchair market, where Rainer Kuschall’s decades-old monotube design is all the rage, with virtually all manual wheelchair manufacturers now offering monotube models. To use another cliché, one might say that the bandwagon is better late then never.

Nevertheless, even though it took 22 years for the monotube to catch on in the U.S., it’s done so for good reason: A monotube makes for a responsive but forgiving ride, in a lightweight, compact package, with a sleek, minimalistic aesthetic.

I’ve used a rigid frame style manual chair for the past two decades, with my most recent built 7 years ago. I’m no jock or super-para by any stretch. In fact, I’m a complete spazzo on wheels – which is all the more reason for me to use a rigid frame, as in for utmost durability and propulsion efficiencies, compensating for my spastic, tone-driven push strokes. So, with my company increasing its presence in the manual chair market, and my needing a new rigid, I was fortunate to be able to put together a frame set of my own this year – a monotube, no less – in time for flying to MedTrade and other upcoming travel.

My frame set aside, the choices that I made toward components – such as rear wheels and casters – are the most applicable topics of discussion, using aftermarket components that are widely available, ones that you might use on your own chair.

Weight is critical toward wheelchair propulsion, especially at the rear wheels. A heavier wheel simply requires more energy to accelerate and propel than a lighter wheel, so the lighter the rear wheels, the easier a manual wheelchair is to push. With this principal, I began with a Spinergy Spox LX rim, which is among the lightest rims available.

If I wished the absolute most efficient, lightest wheel configuration, I would have finished the Spinergy LX rim with an aluminum handrim and a 100psi clincher tire. However, being that I’m using the chair for travel in everyday enviroments, I chose to run a slightly heavier but more practical set-up.

For tires, I went with a 65 psi, 1-3/8” everyday tire. Everyday tires offer better terrain handling, hold optimally with brakes, offer increased puncture resistance, and better maintain air pressure than 100 psi clinchers. Unquestionably, 100 psi clincher tires are far more efficient on ideal, hard surfaces than 1-3/8” everyday tires; but for everyday use on unpredictable terrain, 1-3/8” everyday tires are a sound choice.

The handrims were another choice made out of practicality. I went with ergonomic handrims for better grip over standard tubular handrims. And, indeed, the ergonomic handrims allow a notably comfortable, efficient grip – even on my one hand that doesn’t have a much coordination – and they are tremendously more effective toward uphill pushing and downhill braking. As such, from an ergonomic viewpoint, they are fantastic. However, ergonomic handrims are much heavier than a standard aluminum handrim – about 1 lb. Per side – to the point where the wheel feels heavier. What’s more, because the weight of a handrim is spinning at the outermost portion of the wheel – the most consequential place to add weight to a manual wheelchair – the heavier rotational weight of the handrim surely detracts from performance. However, the question becomes, do the benefits of ergonomic handrims outweigh the drawbacks of extra weight?

In my use, absolutely – the increased propulsion efficiencies that I get from using ergonomic handrims is well worth the trade-off in weight. The ergonomic handrims simply allow me to propel the chair dramatically better (or, at least keep the darn thing rolling in a straight line, which is the best that I can hope for!).

On the front casters, I went big for a monotube with an 80-degree front frame bend, squeezing in 6”, soft-roll front casters. Again, on ideal, flat, hard, smooth surfaces, an 80mm or 4” caster would prove most responsive. However, in everyday use, on unpredictable surfaces, a big, 6” soft-roll makes for an easier, safer ride. And, they are totally smooth, void of chatter on rough surfaces, which is a nice difference from small, hard casters – the chair all but glides. Plus, the aluminum rims are always a classic cool look.

Another practical touch are my quick-release stroller handles, set behind the backrest. On the one hand, I need a low back height for self-propulsion, but then the push handles are too low for others to push me when needed. To address this, I added height-adjustable, quick-release stroller handles that are placed at the right location for a companion, without interferring with my my positioning.

Of course, even though we built my own chair, I wasn’t without fitting issues like many users, where my posture doesn’t like to conform to typical seating and angles – I’m not a sit-and-go kind of fit. As has always been the case, I build my seating as close to my needs as possible, then a lot of tweaking still has to occur with adjustments to angles, cushions, and straps. While I understand this involved process, my ever-teasing daughter viewed it a tad mored bluntly. While fitting myself at home in my new chair one evening, I explained to her that we had to take the chair back to my office for some changes to the backrest, as it wasn’t fitting my angles and posture quite right.

“So, the back is wrong?” she asked

“Yep – I need to make it fit my crazy posture better,” I said, transferring onto the couch, my daughter holding the chair.

“But, you’re the one who made it, right?” she asked.

“Yep,” I replied.

“If you made the back, and it’s wrong…” she said with a smile, “…then that means that you made you’re own chair wrong.”

“Exactly,” my wife chimed in from the kitchen, making my daughter laugh.

“Come here, shorty – let’s see how well you fit!” I said, grabbing my daughter, pulling her onto the couch, tickling her.

“I take it back, I tack it back! You are the WheelchairJunkie!” she exclaimed, laughing hysterically.

Indeed, monotube wheelchairs and kids are fun – and even more fun together.